xvEPA
           United States
           Environmental Protection
           Agency
           Office of Air Quality
           Planning and Standards
           Research Triangle Park NC 27711
EPA-340/1-83-015
January 1983
            Stationary Source Compliance Series
Performance
Audit Procedures
for SO2, NOx,
CO2, and O2
Continuous
Emission
Monitors

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                                                 EPA-340/1-83-015
Performance Audit Procedures for SO2, NOx,
CO2, and  O2 Continuous Emission  Monitors
                               Prepared by:

                         Entropy Environmentalists, Inc.
                           Research Triangle Park,
                              North Carolina
                               Prepared for:

                               Louis R. Paley
                       Stationary Source Compliance Division

                    United States Environmental Protection Agency
                         SSCD Contract No. 68-01-6317
                               Prepared For

                     U.S. ENVIRONMENTAL PROTECTION AGENCY
                     Office of Air Quality Planning and Standards
                       Stationary Source Compilation Division
                           Washington, D.C. 20460
                              January 1983    U.S. Environmental Protection Agency
                                           Region 5, Library (5PL-16)
                                           230 S. Dearborn Street, Room 1670
                                           Chicago, -IL  60604

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The Stationary Source Compliance  series  of reports  is  issued  by the
Office of Air Quality Planning and  Standards,  U. S. Environmental
Protection Agency, to assist Regional  Cffices  in  activities related  to
compliance with implementation plans,  new source  emission  standards,
and hazardous emission standards  to be developed  under the Clean Air
Act.  Copies of Stationary Source Compliance  Reports are available -
as supplies permit - from Library Services, U.S.  Environmental
Protection Agency, MD-35, Research Triangle Park,  North Carolina
27711, or may be obtained, for a  nominal cost, from the National
Technical Information Service, 5285 Port Royal Road, Springfield,
Virginia  22151.

This report has been reviewed by  the Office of Air  Quality Planning
and Standards, U.S. Environmental Protection  Agency, and approved for
publication as received from Entropy Environmentalists, Inc.   Approval
does not signify that the contents necessarily reflect the views and
policies of the U.S. Environmental  Protection  Agency,  nor  does  mention
of trade names or commercial products  constitute  endorsement  or
recommendation for use.
                               ii

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                                  ABSTRACT
     As the Environmental  Protection  Agency  and  State control agencies place




greater emphasis on the use  of S02 and  N0x  continuous emission monitor (CEM)




data, valid and  reliable  monitoring  results increase   in  importance.   S0_




and NO  CEM performance  audits conducted by  the control  agency  provide  an
      A



independent and quantitative evaluation of the accuracy, representativeness,




and  reliability  of  CEM  data  reported  to  the  agency.   Source  owners  and




operators may  also  conduct  performance  audits  to evaluate  their  installed




CEMS and to diagnose operating problems.






     This report presents  detailed performance audit  procedures for a variety




of currently available S0_ and NO   CEMS.   Specific procedures for conducting
                         t      X



(1) initial monitor  inspections/calibration  checks,  (2)  calibration  error




tests,  (3) stratification   tests   at   monitor   sampling   locations,   and




(4) relative  accuracy tests  are  included   for  the   following  monitoring




systems: (1) LSI SM810 S02/N0  and CM50  02 monitors,  (2) DuJbnt  460 S02/N0x




and Thermox 02 monitors,  (3) Contraves-Goerz GEM  100 S02/N0/C02 monitors, and




(4) Environmental Data  Corporation   DIGI  1400  SO /N0/C02  monitors.   These




procedures may be adapted  to other types  of gas emission monitoring systems.
                                  iii

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                        TABLE OF CONTENTS
Section 1.  Introduction	   1
Section 2.  Testing Methodology 	   3
            2.1  Initial Monitor Inspection/Calibration Check 	   3
            2.2  Calibration Error Test 	   4
            2.3  Stratification Test	   5
            2.4  Relative Accuracy Testing	   7
Section 3.  Lear Siegler SMS10 S02/N0 - CM50 02 Audit Procedures. ...  11
            3.1  Principle of Operation	11
                 3.1.1  LSI SM810 SO /NO Monitor	11
                 3.1.2  LSI CM50 02 Monitor	12
            3.2  Initial Monitor Inspection/Calibration Check 	  13
                 3.2.1  Monitor Inspection - SM810 SO /NO Monitor ...  13
                 3.2.2  Calibration Check 	  14
                 3.2.3  Temperature Compensation Check (SMS10 Only) .  .  15
            3.3  Calibration Error Test	  .  16
            3.4  Stratification and Relative Accuracy Tests 	  18
Section 4.  DuPont 460 SO./NO  - Thermox 0~ Audit Procedures	19
                         2   x            2
            4.1  Principle of Operation	19
                 4.1.1  DuPont 460 S02/N0  Monitor	19
                 4.1.2  Thermox 02 Monitor	19
            4.2  Initial Monitor Inspection/Calibration Check 	  20
                 4.2.1  Monitor Inspection - DuPont 460 S02/N0x
                           Monitor	20
                 4.2.2  Calibration Check	22
            4.3  Calibration Error Determination	23
            4.4  Stratification and Relative Accuracy Tests 	  24
Section 5.  Contraves-Goerz GEM-100 S02/N0/C0  Audit Procedures  ....  27
            5.1  Principle of Operation	27
            5.2  Initial Monitor Inspection/Calibration Check 	  27
                 5.2.1  Monitor Inspection	27
                 5.2.2  Internal Calibration Check	28
                 5.2.3  Temperature Compensation Check	29
            5.3  Calibration Error Test	29
            5.4  Stratification and Relative Accuracy Tests 	  29

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Table of Contents
(continued)
Section 6.
Section 7.
Environmental Data Corporation DIGI Series 1400
  SO /NO/CO  Audit Procedures	   31
6.1  Principle of Operation	   31
6.2  Initial Monitor Inspection/Calibration Check	   32
                                                        ...   32
                                                        ...   32
                 6.2.1  Monitor Inspection ....
                 6.2.2  Internal Calibration Check
6.3  Calibration Error Test	    33
6.4  Stratification and Relative Accuracy Tests	    33

Quality Assurance Procedures 	    35

7.1  Method 3	    35

7.2  Method 6	    36
7.3  Method 7	    37
Appendices	    39

            Appendix A.  Stratification Testing Methodology  for
                           Gaseous Effluent  Constituents

            Appendix B.  Reference Method Procedures  -
                           Reference Method  3
                           Alternative Method  for  Stack Gas  Moisture
                             Determination
                           Reference Method  6
                           Reference Method  7
                                   VI

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                               1.   INTRODUCTION






     The EPA and state air pollution  control  agencies are rapidly expanding the




scope and implementation of continuous  emission monitoring programs and placing




greater  importance  on the  use  of continuous emission monitor  (CEM)  data  to




achieve  sustained emission  reductions.   In  some cases,  CEM  data are  used  to




determine compliance with applicable emission standards and  pollutant  control




requirements.






     For continuous monitoring  regulations  to be  effective,  monitor-specific




field performance audit procedures are  necessary to qualify and to quantify the




validity of  the CEM data.   These procedures must provide  consistently valid




results  and  must apply to  a wide range  of  regulatory,  source, and  monitor




conditions.






     This document presents  field  performance audit  procedures  for  CEMS from




four different  major  manufacturers.  These monitor-specific  field  performance




audit  procedures were  developed   using  both  the  manufacturer's  operational




manuals and  first-hand  experience  with the  individual  monitors.   Section 2 of




this report describes  general test procedures  that  are  common  to  each monitor;




Sections 3 through 6 outline the monitor-specific audit procedures for the Lear




Siegler  SM810-CM50,  the  DuBont  460-Thermox, the Contraves-Goerz  GEM-100,  and




the EDC DIGI Series 1400 monitoring systems, respectively.  Section 7 describes




quality  assurance  procedures for  gas  CEM  performance audits.   The Appendix




contains specific sampling  and  analysis  procedures for the  stratification and




relative accuracy method tests required in gas monitor  audits.

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                            2.   TESTING METHODOLOGY






     Performance audits of gas  CEMS include: (1) an initial monitor  inspection




and calibration check,  (2) a calibration  error  test (for those monitors which




accept  calibration  gases),  (3) a  stratification  test,   and   (4) a relative




accuracy test.  General procedures  for conducting each part of  the  audit are




discussed below. Monitor-specific procedures are provided  in Sections 3 through




6; specific  sampling  and analysis  procedures  for  the  stratification and the




reference method  testing  of the  relative accuracy test  are  included  in  the




Appendix.








2.1    INITIAL MONITOR INSPECTION/CALIBRATION CHECK






     An  inspection  of  the  installed  monitoring  system  is conducted  at the




outset of the performance audit:  (1)  to determine if the monitoring  system  is




fully operational,  (2) to  identify and  obtain  values for  monitor  operating




parameters necessary  for  conducting  the  audit,  and   (3)  to  ensure that the



tester  understands  the data  recording system.   Since the  performance audit




provides a  measure  of  the  capability of the  monitor to  provide valid data,




operational problems  identified  during the  inspection should  be corrected  by




the source representative before the other audit activities are  conducted.






     A calibration check  of the monitoring  system is  performed  by  having the




source representative (operator) conduct the required  daily zero and  span check




routine.   As  a  part of  this  procedure,   the  operator  should  adjust  the




monitoring system if  the  observed  zero or  span  drift exceeds the  applicable




limits.  Therefore, at  the  conclusion of the calibration  check  procedure  (and




the check of auxiliary monitoring parameters for  some  monitoring  systems), the

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CEMS should  be  fully  operational  and  properly  calibrated  according  to the




normal  practices of the  CEMS operator.








2.2    CALIBRATION ERROR TEST






     A calibration error test  is  performed  for pollutant monitors that  accept




gas injections. Zero, mid (45-55%  of monitor span),  and  high  (85-95%  of monitor




span)  range  calibration gases are  used  for  the  calibration error  test.   In




addition, a low (20-30% of monitor span)  range calibration gas is  also  injected




to verify the linearity of the monitor.






     A three point calibration error test is performed  for the diluent monitors




that accept  gas injections.   The  following  calibration  gases  are  used: low




(1-3% 02  or  1-3% C02),  mid (6-10% 02 or 5-8% C02), and  high  (air  for  02  or




12-15% C02).  (The high  range test  for oxygen  monitors  cannot  be  performed




unless the monitor span is >^ 21% 0 .)






     All  gases used in  conducting  calibration error  tests must be  analyzed




prior  to  use.   Two methods  are acceptable  for  establishing  the  values  of




calibration gases:  (1)  EPA Traceability  Protocol  No. 1, and (2)  analysis with




Reference  Methods  3,  6,  and  7  utilizing  the  acceptance criteria  for  such



analysis  included  in Paragraph 6.1.1 of the  proposed  revisions to  Performance




Specification  2  (Federal Register, Vol.  44,  No. 197, October 10, 1979).






     For  the calibration error test, a total  of 20 nonconsecutive measurements




for  pollutant  monitors   and  15  nonconsecutive  measurements   for  pollutant




monitors  are  obtained  by alternately injecting each of the calibration gases




(e.g., zero, low, mid,  high,  low, mid,  zero, high, etc.).   The gas injections



(i.e., proper  flow rate  and delivery pressure) must be  performed  in accordance




with the  applicable  monitor-specific procedures  (see Sections  3  and  4  of this

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report.






     For the  calibration error  test,  the responses  of the  pollutant  and/or




diluent monitoring channels are determined from the permanent data record  used




for determining  excess emissions which  are reported  to  the  control  agency.




Comparison of the responses indicated  on the permanent data record  and  backup




recording systems  or instrument panel  meters  (when  used  by the  operator  to




adjust the monitoring system)  should also be performed.  For each gas  injected




during  the  calibration  error test,  the mean  difference  and  95?  confidence




interval of  the  five  measurements  are  calculated and  expressed  both  on  an




absolute basis  (units of concentration)  and a relative  basis  (percentage  of




calibration gas value).  The calibration error  is  calculated as  the  sum  of  the




mean difference and 95?  confidence  interval, and  is expressed as a  percentage




of the test gas concentration.  The  calibration error  test  results  for  only the




mid and  high  range  gases  are  compared  to  the   <_  5%  limit  of   Performance




Specification 2 for pollutant monitors, and to  the same <_ 5% limit for diluent




monitors (proposed  revision to  Performance Specification 3, Federal Register,




October 10,  1979).








2.3  STRATIFICATION TEST






     A stratification test  is performed  to evaluate  the representativeness  of




the CEM  sampling  location  and  to   determine  a  representative  location  for




conducting  Reference  Method  sampling  for  the  relative  accuracy  test.  The




stratification test methodology entails the use of an  extractive, transportable




monitoring  system,  and  is  designed  to  detect  the  presence   of  effluent




stratification. It  does not  provide  a  quantitative   characterization of  the




effluent stratification profile,  nor does it provide  sufficient information to

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determine if a particular measurement  point  or path at  a  stratified location

provides measurements which  are  consistently  representative of emissions.


     The  procedures  for conducting   stratification   tests  are  detailed   in

Appendix  A,   "Stratification  Testing   Methodology   for   Gaseous  Effluent

Constituents."  However, for gas CEM performance  audits,  these  procedures must

be adapted to provide appropriate  results  for the monitor- and source-specific

conditions encountered.   The  following sampling  strategies  address  the most

commonly encountered situations:

     (1)  For  sources where  only  a   pollutant   or diluent  monitor   is
          installed, a stratification  test for  the constituent of interest
          should  be conducted  at the monitor  installation location.

     (2)  For  sources where  both  pollutant  and  diluent  monitors  are
          installed at the same  location and  view the  same  portion of the
          effluent  stream,   concurrent  stratification  tests  for  each
          constituent of  interest  should  be conducted  at  the monitoring
          location.   The measurement  results  for  each  sample  point
          expressed in units of  the applicable  standard  should be examined
          to determine if stratification is present.

     (3)  For  sources where  both  pollutant  and  diluent  monitors  are
          installed at the  same location, but view separate  portions  of
          the effluent  stream,  concurrent stratification tests  for each
          constituent of  interest  should  be conducted  at  the monitoring
          location.   The  concentration measurements of  each constituent
          should  be examined independently to determine  if stratification
          of either component exists at the monitoring  location.

     (4)  For sources where pollutant  and diluent monitors  are installed
          at separate locations, concurrent stratification tests for each
          constituent of  interest should   be  conducted  at  the  pollutant
          monitoring  location.   The  concentration  measurements of each
          constituent should  be  examined  independently to  determine  if
          stratification  of  either  component  exists   at  the  pollutant
          monitoring  location.  In addition, if  the  diluent monitor  is
          installed  at  a  potentially stratified   location,  a  diluent
          stratification  test  should  be  conducted   at   the  diluent
          monitoring  location.    Finally,  if  air  in-leakage  may  occur
          between the diluent and  pollutant  monitoring  locations,  and  if
          diluent  stratification   does  not  exist  at   either  monitoring
          location, then  simultaneous  diluent concentration measurements
          should  be made  at both  locations to detect  and/or  to quantify
          air in-leakage.

     (5)  For sources  where  physical  constraints  require  that relative
          accuracy  sampling  be  conducted   at a  location other  than the

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          monitoring location,  concurrent  stratification  tests  for  each
          constituent  of   interest   should   be   conducted,   and   the
          concentration  measurements  obtained   at  each  sampling   point
          should be examined independently to determine  if stratification
          of any component exists at the testing  location.


     In many cases it is impossible to conduct full traverses of  the stack/duct

cross section during stratification tests due  to  the lack of sampling  ports  or

other physical  constaints.   In  these  situations,   additional  sampling  points

should be included  on  the  traverses which can be  made  (at  least nine  points

should  be  sampled   in  all  cases).  Conclusions  regarding   the presence   of

stratification must reflect the limitations of the  testing  performed.



2.4  RELATIVE ACCURACY TESTING


     Sampling and analysis  for relative accuracy determinations  are  conducted

according to  the  procedures   contained  within   the  revisions to  Performance

Specifications 2 and 3 reproposed January 26,  1981   (Federal Register,  Vol.  46,

No. 16).  Testing is conducted  to  determine  both the relative accuracy  of  the

combined pollutant/diluent monitoring system in  units of the  standard, as  well

as the relative accuracy of each monitoring channel in units of concentration.


     Where  stratification  test results  indicate  that effluent  stratification

exists, the  Reference Method sampling points are  located  in accordance with  the

procedures described in  the proposed revisions  to Performance Specification  2

(January  26,  1981).  Otherwise, a  single Reference  Method  sampling  point  is

located adjacent to the installed CEM measurement point or  path.


     Reference Method tests (Method 6 for  SC-  , Method 7  for NO  , Method 3  for

COp or Op, and  Alternative  Method  4 for moisture) are performed  in accordance

with the procedures prescribed in Appendix A,  40  CFR 60 (see Appendix B of  this

report).  All  effluent  samples are  obtained  via  a single,   5/8  inch  O.D.

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borosilicate glass probe.  The  probe  inlet is  packed  with borosilicate  glass




wool to remove participate matter  from  the effluent sample.  In  addition,  the




probe  is  incased  within  a  stainless  steel  sheath,  and  is  heated to  prevent




condensation  of  water  vapor within  the  effluent  sample  stream.  The  probe




outlet is connected to a heated manifold from which connections can be  made to




appropriate sampling  trains.   Stainless  steel  valves are provided between  the




manifold and  the  sampling train connections.  The temperature of  the  effluent




sample stream within  the  manifold  is  monitored with a  thermocouple to  ensure




that water vapor condensation is prevented.






     Effluent samples are obtained  concurrently during  (at a minimum)  20-minute




sampling runs.  (Longer  sampling runs are occasionally used when  low  effluent




concentrations necessitate larger  sample volumes  in order to maintain  desired




accuracy levels.)  No more than one  sampling  run is conducted  in any  1-hour



period.






     EPA  Method  3  is  employed  to  obtain   integrated,   average   dry-basis




concentrations  of  C02  and   0-.   Triplicate  Orsat   analysis   is   performed




immediately after sample acquisition.






     EPA  Method  6   is  used  to   determine   integrated   average dry  basis



concentrations of S0?.   Midget impingers rather than midget bubblers  are used




to contain  the isopropanol solution which removes sulfuric acid  mist  from  the




sample  stream.   The  outlet   temperature of the  final,  dry impinger  of  the




sampling train is  not monitored, since  it has  been  demonstrated   that  the  S0?




collection efficiency of the sampling  train is greater  than 99 percent when the




impingers are cooled in an ice bath.  Titrations using barium  chloride  solution




are performed on-site.

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     Dry basis,  NO  concentrations are obtained  using  EPA Method 7.  The  three




grab samples that constitute a sampling run  are  spaced  evenly in time over the




run.  In lieu of 50-mL volumetric  flasks,  100-mL volumetric flasks are used  in




the analysis  phase;  the volumes  of  aliquots  are  adjusted  accordingly.  The




arithmetic  mean  of  the  three  grab  sample  results is  reported  as  the N0x




concentration for the sampling run.






     Most continuous monitoring systems analyze  the effluent concentrations  on




a wet basis.  The Reference Method results are on a dry basis;  therefore,  stack




gas  moisture  determinations  are  necessary to  convert  measurements   to   a




consistent  basis.   Moisture  determinations are  performed  according  to the




procedures  described  in  "An  Alternative   Method  for   Stack   Gas   Moisture




Determination" (see Appendix B).  Drierite,  rather than silica gel, is used  in




a Mae West midget impinger to capture water  vapor penetrating the preceding two




impingers of the train.  Samples are obtained at a flow rate of  2 L/min.  Water




vapor  concentrations are  computed  after  each   sampling  run  based  upon the




results from the final weighing of each train.






     For the relative accuracy test, the CEMS data should  be obtained  from the




permanent data record used for reporting of  excess emissions.  Where electronic




data recording  systems  which average  and  display monitoring  data on a  basis



that is  inappropriate  for  direct  comparison with  the  Reference  Method  results




are used, the  CEMS data may be determined  from a backup recording system,  if




available.  In  this  situation,  a  comparison of  the  permanent data record and




the  backup  record  for  each hour  of the  relative accuracy  test  should  be




performed.

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                    3.   LEAR SIEGLER  SM810 S02/N0  - CM50




                                  AUDIT  PROCEDURES
3.1    PRINCIPLE OF  OPERATION






3.1.1  LSI SMS 10 S02/N0  Monitor






     The  LSI SM810  is  a single  point,  in-situ,  dual  pass,  second derivative




spectrophotometer that  employs ultraviolet light  for  the measurement of SO,, and




NO. The ultraviolet light is generated  in  the transceiver unit  and  projected




down the  probe  (normally 6-8 feet  long)  to  the optical cavity located  at  the




end of  the probe.  Effluent  gases  diffuse  into  the  optical  cavity through  a




ceramic thimble which protects against  particulate  contamination.  A portion of




the ultraviolet light is absorbed by the  S02 and  NO,  and the remaining light is




reflected   back  to   the .transceiver.    An  oscillating  monochronometer  then




produces  a detector  output  signal  proportional  to  the  curvature  of  the




ultraviolet absorbance  spectra at different  points  in the ultraviolet spectrum




for S02 and NO.   A converter unit conditions the  transceiver  output to produce



signals proportional to  the  concentrations  of S0_ and  NO  in  parts per million




(ppm) .  Since S02 exhibits a  narrow  band  absorption  at the  wavelengths where NO



is measured,  additional  electronic circuitry subtracts  the  S02 interference




from the NO measurements.






     The SM810 transceiver  employs an  internal   zero device  and  a  sealed  gas




cell for  upscale  calibration  checks.   The  SM810 monitor  is also  equipped to




accept  the injection of calibration gases into the  optical measurement cavity;




the gas injection port  is located on the  flange of the  probe.
                                    11

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3.1.2  LSI  CM50 02  Monitor






     The LSI CM50  is an in-situ, electrocatalytic  oxygen analyzer.  As  the




CM50 samples combustion gases, the partial pressure of the  effluent  oxygen in




the sample side of the analyzer  cell  is lower  than  the partial  pressure of




oxygen in the reference  side,  which  is generally that of air.   When  the  cell




is  kept  at a temperature  of approximately  850°C,  oxygen molecules in  the




reference side pick up electrons  at  the  electrode-electrolyte  interface.   The




CM50's  porous  ceramic  material   (Zr02)  has  the  special  property  of  high




conductivity for oxygen  ions.    This  occurs  because  the  metal  ions form  a




perfect crystal lattice  in the  material,  whereas  the  oxygen  ions do  not,




resulting in vacancies.   Heating  the zirconium oxide causes the  vacancies and




oxygen ions to move  about.  The oxygen ions migrate to  the electrode on  the




sample side of the cell, release electrons to  the  electrode, and  emerge as




oxygen molecules.   The   resultant  EMF is  a  logarithmic  function of  oxygen




partial  pressures.   A  linearizer circuit  processes the  resultant  EMF  to




provide an output   equivalent  to  the oxygen concentration (% 02).






     The CM50 0^ monitor  is designed to accept injection of calibration gases.



The gas  injection  port  is located   on the  flange of  the   sampling  probe.




Normally,  a  low range  0^  gas  and  ambient  air  are  used to calibrate  the



monitor.
                                   12

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3.2    INITIAL MONITOR  INSPECTION/CALIBRATION CHECK


3.2.1  Monitor Inspection  -

       SMS 10 S02/N0  Monitor


     Perform the  following  initial  monitor checks  at the  converter unit  to

determine whether  the monitor  is  functioning properly.


     Check the four  system fault  indicators on the front panel of the converter

unit.
       OPERATE - The "OPERATE"  light  should be on.  If this light is
                 not on, the  control  unit  has lost  power  or  has
                 experienced  a  power  supply failure.

       SCANNER - The "SCANNER"  fault light should be off.  If on,  a
                 change in  the  scanner  amplitude has occurred which
                 may affect instrument  calibration.  The  extent of
                 this problem will  be checked by the calibration gas
                 injections as  described in Section 3.1.1*  of these
                 procedures.

           REF -The "REF"  fault light  should  be  off.   If  on,  the
                 light  returning   to  the  photomultiplier  tube  is
                 below normal operating limits.

        HEATER - The "HEATER" fault light should be off.  If  on, the
                 temperature  controller  on  the  transceiver  has
                 failed, or  power  to  the  transceiver  has  been
                 interrupted.


     Check the reference, input, and  temperature signals at the control unit by

placing the meter select switch in the proper  position.   The reference signal

measures the light  intensity level returning  to the  photomultiplier  tube. If

the  reference  signal  reading  is  not  within   the  green  band   area   (due  to

contamination of the optical  components  in  the analytical  cavity,  and/or to

lamp  degradation) ,  have the monitor  repaired  by  the  source  representative

(operator) before proceeding with  the audit.  Note  the  input signal during the

S02 and NO sampling cycles.


                                 13

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     Check the effluent temperature (°F) at  the monitor  probe tip by  placing

the meter select switch in  the  "TEMP"  position.   A  zero or  offscale  reading

means the monitor is not functioning properly; postpone the audit until  repairs

are made by the operator.



CM50_Og Monitor


     Check the four  operational  parameter indicators located on the front panel

of the control unit to determine whether the monitor  is  functioning  properly.

These indicators are:
       TEMP FAULT - The temperature  fault  light should  be  off.   If  on,  the
                    analyzer  cell  is not at the proper  temperature.   Postpone
                    the  audit until  corrective action is taken by the source.

  HI  CAL/LO  CAL - These  calibration  lights  should  be  lit  only   when  a
                    calibration cycle is performed.

            RANGE - A  selectable range of 2.5%,  10J, and 25% 02 are available.

            ALARM - Preset  alarms  are  illuminated  when  the  monitor  and/or
                    process  parameter indicators  report  data  below or  above
                    preset  monitor  limits.  (These  lights  do  not  indicate
                    improper monitor operation.)
Data Recorders


     Visually check the  S02,  NO,  and 02 data recorders to  see  whether signals

are being recorded.  If  the data recorders are off-scale or  are  not recording

data, have the operator  correct the  problem before proceeding with the audit.



3. 2. 2  Calibration Check


     Ask the  operator  to explain the  conventions used  for interpreting  the

strip chart data (e.g.,  identification of the zero level, scale  factor,  and/or


                                  14

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maximun data display  for  each monitoring channel).   Also,  if the monitor  is




interfaced with a computer  or  other  electronic  data  recorder,  ask the operator




to explain fully the method used  for averaging  and displaying the concentration




measurements, calibration data, and  for  calculating  emission measurements.  Ask




the operator for  the  correct   zero   and upscale calibration check values  for




each monitoring channel.






     Have the source perform the  daily monitor  calibration routine.  Record the




$1810  SOp and  NO monitor  responses for  the  internal  zero  and  span  checks.




Record the  CM50  0^  monitor responses for the  low and  high  range calibration




gases; also record  the gas injection  rate.   If the  correct recorder  responses




(i.e., ^2.5%  of  span)  are not  obtained for both the zero (or  low range)  and




span  checks  for all  of  the monitoring  channels, have  the source adjust  the




monitor before proceeding  with the audit.








3.2.3  Temperature Compensation Check (SM810 Only)






     The  effluent temperature is measured by a  thermocouple located  on the end




of the SM810 monitor probe and is used by the  temperature compensation circuit




to adjust the  second-derivative  signal  amplitude  and  the  resulting  S02 and NO




concentration output levels for temperature  variations.






      Check the monitor thermocouple  calibration by comparing  the monitor stack




gas temperature  readings to actual  effluent gas temperature measurements made




alongside  the  monitor  probe  tip.   If  the monitor  probe  and  effluent  gas




temperature measurements do not  agree  within +_ 2%,  have the source adjust the




monitor   for  the   proper  stack  gas  temperature.    If  adjustments  to  the




temperature measurement/temperature compensation systems are  made,  repeat the




calibration check procedure before proceeding  with the audit.
                              15

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3.3    CALIBRATION ERROR  TEST


     The calibration  error test procedures and  specific  calibration  gases used

for this test are described  in Section 2.2 of  this  report.   Before  initiating

the test, the  proper  calibration  gas injection  rate  must be  established  for

both the SM810 and CM50  monitors.   Establishing  the  proper  gas flow rate  for

the SM810 monitor is particularly critical.  If  the calibration gas flow rate

is too low,  the effluent  gases will diffuse into the  probe  tip cavity,  dilute

the  calibration   gas,  and  cause   an  incorrect monitor   response  for  the

calibration   gas  concentration.  If  the   flow  rate  is  too   high,  buildup  of

pressure in   the cell cavity (i.e.,  an  increase  in  molecules per  unit  volume)

and/or a difference between the calibration gas  temperature and  the  effluent

temperature   (i.e., the temperature  compensation  circuit  will  not  adjust  the

electronics  for the proper temperature) may cause an error in  the  readings for

the calibration gas.


     The following procedures  should be used for  the SM810 monitor:

     (1)  Attach  the  flow meters  and  flow control  valves  between  the
          calibration gas cylinders and the injection ports and adjust the
          regulator delivery pressure to  about  10  psig  for each of the
          calibration gases.

     (2)  Inject  a high range  calibration gas (use  SO,, for  S0?/N0 and  SO
          monitors; use NO only  for NO monitors) .   Slowly open the flow
          control valve  until the  gas injection rate reaches 2. OL/min
          (the gas injection rate  specified by  the  manufacturer) .   Inject
          the gas  for  at least  U  minutes for  a single  gas  monitor  (1
          minute  sample/hold circuit) or at least 6 minutes for a dual gas
          monitor (2 minute sample/hold  circuit) ,  or  until  the  monitor
          indicates a  stable response for  two successive sampling  periods.
          Record  both the time required to achieve  a  stable  response and
          the concentration value indicated by the monitor.

     (3)  Increase the  gas injection rate  to 2.5  L/min.   Allow sufficient
          time for  the  monitor  response  to   stabilize   and   record  the
          concentration value  indicated  by the  monitor.  If the  monitor
          response at 2.5 L/min is the same as 2.0 L/min, all gases should
          be injected  at  2.OL/min for  the  calibration  error test;  no
          further preliminary  testing is necessary.
                               16

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     (4)  If  the  monitor  response  at  2.5 L/min  is  greater  than  the
          response   at   2.0 L/min,  adjust  the  gas   injection   rate   to
          1.5 L/min,  allow sufficient time to  obtain a  stable  response,
          and record  the concentration value indicated by the monitor.   If
          the responses at 1.5 L/min and  2.0 L/min  are the  same,  inject
          gas at approximately 1.7 L/min  for the calibration  error  test;
          no further  preliminary testing is necessary.

     (5)  If the monitor response  at 1.5 L/min is less  than  the response
          at 2.0 L/min,  repeat  step (4) using 1  L/min gas injection rates.
          Inject all  gases  at  1.2 L/min if the responses at  1.0  L/min  and
          1.5 L/min  are  the same.   If not, proceed with step (6).

     (6)  Inject a  zero gas at  1.5 L/min  and record  the monitor response
          after it  stabilizes.  (A  small positive offset will  probably be
          observed  since the monitor  amplifies positive  noise  and ignores
          the negative  noise  at the  zero  concentration  level) .   Decrease
          the zero  gas injection rate in intervals of 0.25 L/min until  an
          increase  in  the  stablized  zero gas response   is  seen.   Ihis
          indicates that the gas injection rate is too low to  prevent  the
          diffusion of  stack gases  into the measurement cavity. Inject  all
          gases for  the  calibration  error test at  a rate of 0.25 L/min
          greater  than   the  flow rate  which  exhibits  an  increased  zero
          response.

     (7)  Record the  flow rate  used for the calibration error test and  the
          time allowed  for  injection of each gas.
     The response  of the  CM50 0^ monitor is much less  sensitive  to  calibration

gas  injection  rates  than  the  SM810  monitor.   For  the  CM50  monitor,  0

calibration gases  should initially  be injected  at  the  same   flow  rate  as

observed during the  daily calibration procedure.  Calibration gases should also

be injected at  0.5 L/min  above and below the initial  injection  rate  to  verify

that the monitor response is unaffected.  If  a  consistent monitor  response  is

not obtained during  these preliminary tests, then a procedure equivalent  to the

above steps for the  SM810 monitor  should  be  followed  to determine the  proper

calibration gas injection rate.
                                17

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3. M  STRATIFICATION AND RELATIVE ACCURACY TESTS






     Before initiating the relative accuracy test, perform a statification  test




at the monitor  location  using  the  procedures  presented  in  Section  2.3  and




Appendix  A of this document.   Conduct the relative accuracy test  in  accordance




with  the   procedures  in   Section  2.4  and  the  Reference  Method  procedures




delineated in Appendix B of this document.  Moisture testing must  be conducted




during the relative accuracy tests to  facilitate comparison of the wet basis




SM810/CM50  concentration  measurements and  the  dry  basis  Reference  Method




results.
                                    18

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                      4.  DUPONT 160 S02/N0x  - THERMOX 02




                                  AUDIT  PROCEDURES




4.1    PRINCIPLE OF  OPERATION




4.1.1  DuPont 460 S02/N0x Monitor






     The DuPont  460 S0p/N0   gas analyzer  is an extractive monitor  which uses
                      <—   X



differential  ultraviolet  radiation  adsorption  to  measure concentrations  of




sulfur dioxide and oxides of nitrogen.  The monitor sequentially cycles through




a  sampling  mode and a  purge mode for  the SOp and NO   monitoring channels.




First,  the  sample  cell  and  line are  purged  with  ambient  air  and the  S02




channel's zero  is automatically adjusted.  Next,  a sample is  drawn  from  the




effluent stream  through  heated  sample lines  equipped  with  filters  for  the




removal  of   particulate  matter.   The   sample   is then   pulled  through  the




condensate   trap and  into  the  sample  cell, where the  SO,,  concentration  is




measured. Tne sample cell and line are  then  purged with ambient air, and  the




N02  channel's zero  is  automatically  adjusted.    Finally, a   second effluent




sample is pulled through the condensate trap and  into  the sampling  cell where




the  N02 concentration  is measured.   The  cell   is then  sealed) and  oxygen  is




injected into the  cell  to  convert  the  NO in  the sample  to  NO,, which  is




subsequently measured and recorded as  the NO  concentration.   At  this  point,
                                             A



the  cycle   is   repeated.    Tne   SOp   and   NO    measurements   are  converted




electronically to an input signal  for  the  data  recording  system.






4.1.2  Thermox 02 Monitor






     The  Thermox  02 monitor  is an   extractive   analyzer which   employs  an




electrocatalytic process in the analysis of oxygen.  It is installed within the




DuPont  460  analyzer cabinet  in  a functionally parallel  arrangement with the
                                  19

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DuPont 460 sample cell. Curing the  S02  portion  of the DuPont  sampling  cycle,



combustion gases enter the analytical chambers of both the  DuPont  and Thermox



analyzers and concentrations of S0_  and  Op are measured concurrently.





     In the  Thermox  0^ monitor,  the  partial  pressure of the  oxygen in  the



sample side of the cell  is lower than the partial pressure of the oxygen in the



reference  side,  which  is  generally that  of air.   The  cell  is   kept  at  a



temperature  of  about 850°C;  at  this  temperature,   oxygen  molecules  in  the



reference side will pick up electrons at  the  electrode-electrolyte  interface.



The cell is composed  of  porous ceramic material which  has  the  special  property



of high conductivity  for oxygen ions.  This occurs because the  metal ions form



a  perfect  crystal  lattice in the material,  whereas the  oxygen ions do  not,



resulting in vacancies.  Heating this material causes  the  vacancies  and  oxygen



ions to move  about.   The  oxygen ions  migrate  to  the  electrode on  the  sample



side of  the cell,  release electrons  to the  electrode, and  emerge as  oxygen



molecules.   The  resultant EMF is   a  logarithmic  function  of  oxygen  partial



pressures.  Also, a linearizer circuit processes this EMF to give an output  in



units of  concentration  (% 0^).   The 02 measurements derived  by the  Thermox



analyzer are converted electronically to an input  signal to  the data recording



system .






4.2    INITIAL MONITOR INSPECTION/ CALIBRATION CHECK





4. 2. 1  Monitor Inspection  -



       DuPont 460 SOo/NO  Monitor
     Various types  of control  units are  used  for  the  DuPont  460  S05/N0
                                                                         £   X


analyzers; therefore,  no universal monitor  checks  can be  established.   Check



the control unit to determine that power is  being  supplied.   Visually inspect
                                  20

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the monitor  to see  whether  it is cycling  and supplying  an  output signal  to



drive  a data  recorder.  If  there are  any  problems  in  these  areas,  do  not



continue with  the  performance  audit  until  the problems have been corrected  by



the source representative (operator) .






     Various types and  configurations  of field units  (analyzer cabinets)  are



used  for  the  DjPont 460  S02/N0x  analyzers.   Visually check  the  monitor



parameters against the factory supplied  specification  sheets  (e.g.,  sample cell



pressures, air regulator supply and working  air pressures,  oxygen pressure (NO
                                                                             A


monitors only), sample flows, the cycling of pnuematic  control valves, and  the



sample  line  heater voltage/cur rent levels) .  Make  sure that  these  monitoring



system  functions are working properly (corrected by the operator, if necessary)



before continuing with the  audit.   Record  the sample  cell pressure and sample




flow rate  for the  S02  and  N02  channels.  Visually determine the location   at



which calibration  gases  are injected  in   the monitoring  system.    Note   the



cylinder gauge presure  and  regulator delivery pressures  for each  calibration



gas.






Thermox 0^, Monitor






     Check the Thermox control unit to  see  that power  is  being supplied to  the



monitor and that the  presence  of an output  signal  is indicated by the panel



meter.   At the IXaPont  field  unit,  observe and record the  0_  sample flow rate



during  the SO  sampling  cycle.   Determine the location where calibration gases



are injected  into the monitoring system.   Note the  cylinder gauge pressure  and



regulator outlet  pressure for each 0« calibration gas.
                                    21

-------
DuPont/Thermox Data Recorder






     Visually check the  SC>2,  NOX, and  Op  data  recorders  to  see whether signals




are being recorded.  If  the data recorders are  off-scale or are not recording




data, have the operator  correct  this problem before continuing the audit








1. 2. 2  Calibration Check








     Ask the  operator  to explain  the conventions used  for  interpreting  the




strip chart data (e.g.,  identification of the  zero level,  scale factor, and/or




maximum  data display for  each monitoring  channel).   Also,  if  the  monitor is




interfaced with a computer or other electronic data recorder,  ask the operator




to explain fully the method used for averaging and displaying  the concentration




measurements, calibration data,  and for calculating emission measurements.  Ask




the operator for the correct zero and  upscale  calibration check  values  for  each




monitoring channel.  Some DuFbnt  460  monitors are supplied  with glass filters




to  simulate  a  specific gas  concentration.   The  values of  these  filters  are




included  with  the  factory specification sheets.   All  DuPont  460  S02/N0x  and




Thermox  0  monitors  should be equipped for injection of calibration gases for



the daily  zero and  span  checks.  For  the  Thermox monitor,  a  low  range check




(e.g., 0.8% 0?) should be substituted  for the  zero check.






     Have  the  operator  perform  the daily  monitor calibration routine.  Record




the zero and upscale calibration responses for each monitoring channel.   If the




correct  recorder responses (i.e., +_ 2.5% of span)  are not obtained  for  both the



zero and span  gas  injections  for  each  monitoring channel,  have the  operator




adjust the monitor before proceeding  with the  audit.
                                22

-------
it. 3    CALIBRATION ERROR  DETERMINATION






     Zero  gases  and  upscale  calibration  gases  must be  introduced  to  the




Du Pont/Therm ox monitoring  system at the junction of the sample probe outlet and




the heated sampling lines.   For some DuFbnt M60 Thermox monitors, the injection




of calibration gases  at  the  sampling  probe  outlet may  be accomplished  from




remote injection  ports, and  may be controlled by operation  of  solenoid  values.




Otherwise, the manual gas injection procedure described  below should  be  used.




The calibration error test  procedures and  specific  calibration  gases  used  for




this test are described  in  Section 2.2 of  this report.   Before  initiating  the




test,  the  proper  conditions for  injecting  the  gases  must  be  carefully




established.






     Depress the  calibration  cycle  button to  activate  a  solenoid  valve  that




closes off the monitor sample  probe and opens the calibration gas  lines to  the




monitor.  Adjust  the calibration gas flow rate to  provide the  same sample flow




rate for calibration gases as  observed  during  the  daily calibration.  Continue




to  inject each  gas until  consecutive  recorded   responses for  that  gas  are




identical. These  multiple injections are  important  since  the  initial injection




may have  occurred  in  mid-cycle; to  obtain  a  correct  reading,  the calibration



gas  must  be  injected  into  the  monitoring  system  at  the  beginning  of  a




calibration cycle.






     If calibration gas ports  are not  available,  remove  the  sample  line  from




the monitor  probe.   Insert  a  tee  in  the sample line, and  attach  a  flow meter




and flow control  valve to one  leg  of the tee. Leave the  third  leg open to the




atmosphere.  Attach the  flow  control valve and  a  flow meter  to  a calibration




gas cylinder, and adjust  the regulator  pressure to  approximately  10 psig.  Open
                                 23

-------
the flow control valve until an 8  cfh  reading  is obtained  on the  flow  meter.




Allow the monitor to draw its own  sample  during  the calibration cycle.   Vent




the excess calibration gas through  the  third leg of the tee.  Allow the monitor




to run through several cycles, until  respective portions of consecutive  cycles




are  identical.  Since  the  Thermox  0? monitor  is  incorporated  within  the




DuPont 460,  introduce the calibration gases into the Ihermox in the same manner




as the gases for the DuPont  460 monitor.








4.4    STRATIFICATION AND  RELATIVE  ACCURACY TESTS






     Before initiating the relative accuracy test, perform a statification test




at the monitor  location  using  the  procedures presented  in  Section 2.3  and




Appendix  A of this document.  Conduct the  relative  accuracy  test  in accordance




with  the  procedures  in   Section   2.4  and  the  Reference  Method  procedures




delineated in Appendix B of  this document.






     The   DuPont  460 S02/N0   monitoring  system  may  remove a  portion of  the



effluent  moisture from the sample stream  and  provides effluent measurements on




a "partially" wet basis.   Therefore, moisture determinations may be required at




either of two locations:  (1) the same  location as  the  Reference  Method  probes



or (2) at the monitor's condensate  trap.   At  some  sources the  moisture content




of the monitor-analyzed  sample need  not  be measured during  relative accuracy




tests.  The appropriate moisture determination  procedure  and sampling location




must  be   determined   for  the   particular  effluent  conditions   and  monitor




operation.






     The  following  list presents the  appropriate  moisture  determination method




and sampling location  for  specific  conditions.
                                 24

-------
1.   Reference Method sampling  at monitor  location:






    This method is utilized  if the  effluent  stream  is not  saturated at the



    monitor location and  if  the analyzer  sample  stream  is not saturated at



    the exit of the condensate trap.






2.   Reference Method sampling  at monitor  condensate trap:






    This   method    is   utilized    if    the    effluent   stream    is




    saturated/supersaturated  at    the   monitor  location  and   if   the



    monitor-extracted  sample stream is not  saturated  at the exit  of the



    condensate trap.






3.   Theoretical moisture  determination:






    This method  is utilized  if  the monitor-extracted  sample  stream  is



    saturated  at  the  exit  of the  condensate  trap.   If  this  situation



    exists, the temperature  of the  condensation trap must  be  monitored,



    and the  sample  stream moisture content  is  determined  through the use



    of steam tables or  psychrometric charts  adjusted  to the sample stream



    pressure.
                               25

-------
                  5.      CONTRAVES-GOERZ  GEM-100 SC>2/NO/C02




                                 AUDIT  PROCEDURES




5.1    PRINCIPLE OF OPERATION






     The Contraves-Goerz GEM-100 is a single  pass, cross-stack, in-situ monitor




utilizing a non-dispersive infrared analyzer which  compares  the  absorption of




selected wavelengths by the  effluent  stream  with  reference  values,  thereby




correlating the relative absorption value  to  the gas concentration of interest.




The monitoring  system  is comprised of three components: (1)  a  stack-mounted




infrared source, (2) a  stack-mounted analyzer, and  (3) a control/display unit




that  provides  strip chart  records of SO,,,  C02,   and  NO concentrations  and




effluent  temperature,   a  run/calibrate  switch,   and   three   system   status




indicators.  The  GEM-100 analyzer  employs internal  sealed   gas  cells  and  an




alternative infrared  light source to provide  a  single-point upscale calibration




check for each monitoring channel.








5.2    INITIAL MONITOR  INSPECTION/CALIBRATION CHECK






5.2.1  Monitor Inspection






     First, check the control/display unit.   The control unit is equipped with



one two-pen  recorder and one  three-pen  recorder.   (The  third  pen  records CO




measurements, provided  that  this  function is incorporated into the monitoring




system.)  Check these recorders to verify that  all pens are on  scale.






     The control  unit   also   includes  three  system  status  indicators and   a




run/calibration switch.   Check these as follows:
                                 27

-------
     POWER  FAILURE -  This  red  light  should  be  off.   When  lit,   the
                      monitoring system has lost power.

     WINDOW  DIRTY  -  This red  light  should be  off.   When  lit,  one  of
                      several  problems associated  with the  stack  source
                      IR  signal  is indicated.

        CAL  STATUS  -   This red  light may either be off or  lit;  when  lit,
                      the analyzer is in a calibration mode.

     RUN/CALIBRATE  -   This  switch  activates the calibration mode of  the
                      monitor.   The  switch   should   be   in  the   "RUN"
                      position  for normal operation.
     Any problems  with  the  system  status  indicators and  their  associated

subsystems  should be  corrected  by a  source  representative  (operator)  before

resumption  of the audit.


5.2.2  Internal Calibration  Check


     Ask the  operator to explain  the  conventions  used  for  interpreting  the

strip chart data (e.g., identification of the  zero  level,  scale factor, and/or

maximum display value for each monitoring  channel).   Also,  if the  mon-tor  is

interfaced  with a computer or  other electronic  data  recorder, ask the operator

to explain  fully the method  used  for averaging  and  displaying  concentration

measurements, calibration data, and calculated  emission measurements.  Ask the

operator for the correct  calibration  check  values for  each monitoring channel.


     Have the  operator perform the daily monitor  calibration  routine. Record

the values  for the  upscale  calibration  check for each monitoring  channel.  If

the proper  responses  (i.e., +_ 2.5% of span)  are not  obtained  for  all  of the

monitoring  channels, have the  operator make the appropriate  adjustments before

proceeding  with the audit.
                                  28

-------
5.2.3  Temperature Compensation Check






     The GEM-100 monitor output signals vary with  stack  gas  temperature  for a




given operating pressure  in  the  duct/stack and  for a fixed  concentration  of




pollutant  and/or   diluent gas.    At  higher  temperatures,  there  are  fewer




molecules at  a given pressure, and  hence, there  are  fewer  molecules of  the




absorbing gas in the path between  the  source and  the sensor.   In  addition,  the




strength of  the absorption  lines is  somewhat  temperature dependent.   These




effects are compensated  for electronically  in the instrument.






     Check the monitor's thermistor probe calibration by  comparing  the monitor




stack temperature readings to actual  effluent gas  measurements made alongside




the thermistor  probe.   The temperature measurements should agree  within  +_ 2%;




otherwise, have the operator  adjust the monitor  for the  proper  response.   The




internal calibration check should  be repeated if adjustments to the temperature




measurement system are made.








5.3    CALIBRATION ERROR TEST






     The  GEM-100  monitor  does not   allow injection  of  calibration  gases;




therefore, a  calibration error test cannot  be performed.








5.4  STRATIFICATION AND  RELATIVE ACCURACY TESTS








     Before initiating the relative accuracy test, perform a statification test




at the  monitor location  using  the procedures  presented in  Section  2.3  and




Appendix A of this document.  Conduct  the relative  accuracy test  in accordance




with  the  procedures  in  Section   2.4 and  the  Reference  Method  procedures




delineated in Appendix B of this document.  Moisture testing must be conducted






                                 29

-------
during the relative accuracy tests to facilitate comparison  of the wet  basis




SM810/CM50  concentration  measurements and  the  dry  basis  Reference   Method




results.
                                  30

-------
        6.  ENVIRONMENTAL DATA CORPORATION DIGI  SERIES  1400 S02/N0/C02




                                AUDIT PROCEDURES




6.1    PRINCIPLE OF OPERATION






     The  EDC DIGI  1400  gas  analyzer  is an in-situ,  single  pass, cross-stack,




flue gas monitor designed to measure concentrations  of S02,  NO,  and C02-  The




measured  gas concentrations  are  displayed   on strip  chart  recorders  on  a




real-time  basis,  in  units  of  concentration.   The   DIGI   1400  utilizes  a




differential absorption  analyzer,  which  operates on  the   principle  that  a




specific gas absorbs electromagnetic radiation  at  specific  wavelengths within




the  radiation   spectrum.   For  a  particular  gas,  the  monitor  compares  the




absorption  of  radiation by  the  effluent stream  at  a  wavelength which  is




absorbed by the  gas  of  interest to the absorption at  a reference  wavelejgth.




The  selected measurement  and reference  wavelengths  are very  close  together,




ensuring that any attenuation due  to  other  gases will be  approximately equal  at




each wavelength.  The effects of such attenuation will  therefore tend to cancel




each  other,  resulting   in   minimized   interference   from   other  gases.  The




measurement  and  reference   wavelengths   for  both  NO  and  SOp  are  in  the




ultraviolet region,  while  those for C0_  are  in the infrared portion of  the




spectrum.






     The monitoring system utilizes three  basic  components.  The "source"  unit,




which generates  the ultraviolet  radiation,  is mounted on one side of the stack.




The  "analyzer"  unit is  mounted  directly  across  from  the   source  unit,  and



contains  the  necessary  optical  and  electronic   components  to measure  the




differential absorption  of ultraviolet and infrared  light by the  effluent  at




various   wavelengths  and   to  generate   an    output   proportional    to   the




concentrations of the gases of interest.   The "display" unit records the output




data from the analyzer unit and  can be  located anywhere.
                               31

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     The DIGI 1400 analyzer employs internal sealed gas cells to  facilitate  a




simulated zero check and  upscale calibration check for each monitoring channel.




Some DIGI  1400  monitor  installations  are equipped  with  a "zero  pipe"  (e.g.,




concentric, slotted pipes enclosing the  cross-stack optical  beam).   The  zero




pipe can be closed and  flooded  with  ambient air by the  purge air blowers  to




facilitate a cross-stack  zero check.








6.2    INITIAL MONITOR  INSPECTION/CALIBRATION CHECK






6.2. 1  Monitor Inspection






     Check the strip chart  recorders to verify that the outputs of the analyzer




are  displayed  within  the  recorder   scales.   If  any of the  recorders  are




off-scale,  ask  the   source representative  (operator)  to  adjust  the  ^ata




recorders before continuing.






6.2.2  Internal Calibration Check






     Ask the  operator  to explain  the  conventions  used  for  interpreting  the



strip chart data (e.g., identification of the zero  level,  scale  factor, and/or




maximum data display for each  monitoring channel).   Also,  if the monitor  is




interfaced with a computer  or other electronic data  recorder,  ask the operator




to explain fully the method used  for  averaging and displaying the concentration




measurements, calibration data,  and for calculating  emission measurements.  Ask




the operator  for  the correct "zero"  and  upscale calibration check values for




each monitoring channel.






     Have  the operator perform  the daily monitor calibration  routine.  Record




the values for the zero and upscale checks for each monitoring  channel. If the




correct recorder responses (i.e.,  +_2.5% of span)  are  not obtained  for all of






                                 32

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the monitoring  channels,  have the  operator  make  the  appropriate  adjustments




before proceeding with the audit.






     If the monitor  has  a "zero  pipe"  installed  cross-stack, perform  a z-ro




check  by  flooding  the  zero  pipe  with air.   Record  the  response  of  each




monitoring  channel  for the  cross-stack zero  check.   If  adjustments to  the




monitor are made as a result of the  zero  check,  the  internal  calibration check




should be repeated.








6.3    CALIBRATION ERROR  TEST






     The  EDC DIGI  Series  1MOO   monitor  does  not  allow  the  injection  of




calibration gases, therefore a calibration error test cannot be performed.








6.1  STRATIFICATION AND RELATIVE ACCURACY TESTS






     Before initiating the relative  accuracy test, perform a statification test




at the  monitor  location   using  the  procedures  presented   in  Section 2.3  and




Appendix A of this document.   Conduct the relative accuracy test  in accordance




with  the   procedures  in   Section  2.4  and  the  Reference  Method  procedures




delineated in Appendix B of this document.  Moisture  testing  must  be  conducted




during the relative  accuracy tests  to  facilitate comparison  of the  wet  basis




SM810/CM50  concentration  measurements  and  the  dry  basis  Reference  Method




results.
                                33

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                       7.   QUALITY ASSURANCE PROCEDURES








     The  EPA Methods applied for relative accuracy tests and  for  calibration




gas analyses are supplemented by  quality  assurance  activities  which entail




assessments  of  quality  control.   The  quality  control assessments and  the




criteria  that  indicate  acceptable  quality  control  are  described  below.




Included with each description .








7. 1  METHOD 3








     Quality control of EPA Method 3 is assessed before and during application




in the field; two techniques  are  employed.   The  first technique is applied




immediately before the analysis of field samples and entails determinations of




known concentrations of C02 and 02 mixtures contained within aluminized  Mylar




bags.  These bag samples are prepared  at  the  Entropy  laboratory  prior   to




departure  to the field.  The gas mixtures used to fill the bags are  obtained




from gas cylinders which have concentrations  of  C02  and 02 (the balance  gas




component is nitrogen, N ) selected so as to be consistent with concentrations




ordinarily encountered within the  effluent streams of fossil-fuel-fired steam




generators.  The cylinder  concentrations  of  C02  and  02 are established by



either: (1) the "Traceability Protocol for Establishing True Concentrations of




Gases Used for Calibration and Audits of Continuous  Source  Emission Monitors




(Protocol  No.  D,"  contained  within  Quality  Assurance  Handbook  for  Air




Pollution  Measurements  Systems,  Volume   III,  Stationary  Source  Specific




Methods, EPA-600/4-77-027b, August  1977;  or  (2) the procedures and criteria




contained  within the revisions to Performance Specification  2,  proposed   in




Federal Register. Vol. 44, No.  197,  October  10,  1979,  p. 58617.  Protocol 1
                               35

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determinations are conducted   by  the   U.S.  EPA,  Quality Assurance  Division at




their  laboratory  in  Research  Triangle   Park,  North  Carolina.   All  other




determinations are performed  by Entropy personnel  at  the Entropy laboratory.




     Two  bag  samples  containing  C02 and  02 at  two different  concentration




levels  are  determined  prior  to  each  series   of  Method   3  sampling   runs




performed.  These determinations are conducted by the   persons responsible for




analyzing the Method 3 field  samples.   The criteria for acceptable  quality are




results within 0.2% CO  and  0.2%  0  of the established concentration values.




Analyses of field samples commence only when quality  control  is established.




     The second technique  for assessing quality  control is applied during the




Orsat analyses of the individual field  samples.   The technique, termed  the FQ




technique, is based upon the  stoichiometries associated with  the combustion of




specified fuel types.  The F   technique has been  proposed  as  a revision  to EPA




Method  3: Federal Register.  Vol. 17,  No.  173, September 7,  1982, pp.  39204   -




39205.   The acceptability criterion recognized by Entropy is the same as  the




one contained therein.








7.2  METHOD 6








     Quality control of the analysis phase of EPA Method 6 is assessed through




the use of "Stationary  Source  Quality  Assurance  S02  Reference  Standards,"




provided by the Quality Assurance Division (QAD)  of the U.S.  EPA.   Immediately




before titrating  S02  samples  obtained  from source effluents  or  calibration




gases, two or more S02 Reference Standards are determined  in  a  "blind"  fashion




by the person responsible  for analyses using the procedures  prescribed  by the




QAD.  The analysis phase of EPA Method  6   is  considered   to be in a state  of
                                36

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quality control if results of the  S02  Reference  Standards'   determinations  are




within +5% of the nominal  S02 mass value.   The  source  effluent  and  calibration




gas S02 samples are analyzed  only  after  quality  control  has  been  established.









7.3  METHOD  7








     Quality control of the analysis phase  of Method 7 is  assessed  using   two




procedures.   One procedure is directed toward the  linearity  of  the  calibration




curve  used   for  relating   absorbance   measurements   to   masses  of  N02.




Accordingly, the spectrophotometer calibration  factor  (identified as KC within




Method  7)  is  first computed.  Following  this  computation, each of the  four




absorbance calibration values are  multiplied  by  the   KC  value   to afford  the




corresponding  N02 masses,which  are then compared  to   the  theoretical  masses




contained in each  sample,  i.e.,   100   yg,  200  yg,  300  yg, and 400 yg.   The




quality of the calibration curve is considered acceptable  if not more than  one




of the computed N02 masses differs  by   more  than 5  percent  relative to  the




corresponding theoretical  mass.




     The other quality control procedure entails the analysis   of   "Stationary




Source  Quality  Assurance  NOX  Reference  Standards," provided by  the Quality




Assurance Division (QAD) of the  U.S.  EPA.   Two  or  more  of these  samples  are



analyzed in  a "blind" fashion using QAD  prescribed procedures.  Results within




7 percent of nominal N0_ mass values are considered  indicative   of acceptable




quality.



     Spectrophotometric measurements are not  conducted on  source  effluent  or




calibration  gas NOX samples until  quality   control of   the  Method 7 analysis




phase has been indicated from the  results of  both  procedures described above.
                                37

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              APPENDIX A.

STRATIFICATION TESTING METHODOLOGY FOR
    GASEOUS EFFLUENT CONSTITUENTS

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                    STRATIFICATION TESTING METHODOLOGY FOR




                         GASEOUS EFFLUENT CONSTITUENTS






     Stratification is the uneven distribution of the  effluent  component  gases




across the cross section of the ductwork or stack which transports the effluent




to the atmosphere.   Stratification of gaseous constituents (S0?,  NO  ,  0?,  CO-,




etc.) may occur at  or downstream of points along the effluent pathway where the




concentration  of  one  of more  constituents  of  the  effluent changes.   Thus,




points at which air  inleakage  occurs, points at  which control  devices  affect




pollutant emission levels  (such as at the outlet  of flue gas  desulfurization




systems), and points at  which  dissimilar gas streams are  combined,  may  result




in stratification of the effluent stream.  Samples obtained  at  locations  where




stratification exists may  not  provide results which  are  representative  of the




entire effluent stream.  It is,  in  some  cases,  necessary to  conduct  a test to




detect and/or  quantify  the  existence  of  stratification  at  the existing  or




proposed  sampling site.   The procedures  presented in this report are designed




to determine whether effluent  stratification is present;  this methodology does




not quantify the stratified effluent profile.






     Current Performance Specifications  for  gaseous  emission monitors require




that monitors be installed  in  locations  which  provide measurements  which are




(or can be  corrected  to  be)  consistently representative of  emissions from the




source.  These  regulations allow the control agency  to  require  stratification




testing at proposed CEM sampling locations where the location cannot be assumed




to be non-stratified.






     Proposed  revisions  to  the  Performance Specifications  (Jan.   26,   1981,




Federal Register) allow  the monitor to be  installed  at any  location provided
                                    A-2

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that  the  reference method testing to determine  the relative  accuracy of  said

monitors  be  performed  in  locations  that  are representative  of  the  source's

emissions.  Stratification  testing  is  an accepted  means  of demonstrating  that

particular  sampling  locations  provide  representative  emission  measurement

results.


     Stratification can be measured for either pollutant gases  (S0?  or NO ) or

diluent gases  (0_  or COp) in units of  concentration.  Alternatively,  at  steam

generators,  stratification  may be  quantified  in  units  of  the  applicable

standard  (ibs of  pollutant  per  million  Btu  of  heat   input).   This  second

alternative  is  useful  where  both  the  pollutant  and   diluent  monitors  are

installed  in  such  a manner as  to view  the  same  portion  of the  effluent,  and

where the  potential  for stratification  is  due  only to  air  inleakage.  Also,

testing  to determine  the  representativeness  of  a compliance  test  sampling

location should be conducted in units of the standard.


     The only  quantitative  definition  for stratification which is provided  in

the  existing  regulations  is  contained   within  Paragraph  3-9,   Performance

Specification 2,  Appendix B, 40 CFR 60.   The definition is as  follows:


     "3«9  Stratification.   A  condition  identified by  a  difference  in
     excess of 10 percent between the average concentration in the duct or
     stack and the  concentration  at  any point more  than  1 .0  meters  from
     the duct or stack wall."


     Paragraph 4.3 of said  specification provides the only guidance  regarding

the sampling methodology to be used  to  determine  whether  stratification exists;

this paragraph reads:


     "4.3.   The owner or  operator  may  perform a  traverse  to  characterize
     any stratification  of effluent  gases ...  ."
                                   A-3

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     Thus, stratification  testing  is  performed  by making a  series  of traverse




measurements across the stack or duct sampling location.  To determine whether




or not effluent stratification exists as per the above  definition,  the average




effluent concentration across the stack or duct  must also be  known  during each




measurement made  along  the stack  traverse.   Determining the  average effluent




concentration  concurrent   with  each  traverse  point raeaurement  presents  some




difficulties.   Ideally,   concurrent   determinations    could   be   made   by




simultaneously measuring emissions at several points along the cross section of




the  duct  or  stack.  However,  this approach  is not  feasible  because of  the




extensive manpower  and  equipment  required  to measure  spatial stratification.




To  ensure  that the  stratification determination is not affected  by temporal




changes  in  the  average  effluent  concentration, a sampling  and  calculation




method was developed to eliminate the effects of such temporal variations. This




method employs  a  dual  probe system to  sample alternately at  a  traverse  point




and  a reference point.






     Steady  operation  is   preferable  for stratification  testing,   because  the




results  are  unaffected by incremental  effluent concentration  shifts due  to




changing process conditions.  If stratification  testing is performed on sources




operating  under  batch  process  conditions,  the  testing should  be  conducted




during segments of steady  operation.
EQUIPMENT DESCRIPTION
     The  sampling  apparatus  necessary   for   stratification   testing  is  an




extractive  continuous  monitoring system comprised of  the  following:   a sample




acquisition  and gas conditioning  system;  SCL,  CCU,  C^,  and/or  NO  monitors;




strip chart  recorders; and an automatic data  processor (optional).  The sample
                                     A-4

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 acquisition  system  consists  of  two  heated  stainless steel sampling  probes,  and




 the  monitoring   system   is   capable   of  alternately   measuring  the  effluent




 extracted  through  each  of  the  two  probes.   A  detailed  description  of  the




 extractive   monitoring   system,  along  with   its  calibration  and   sampling




 procedures,  is  contained in a  document  prepared for  the  EPA,  SSCD,  entitled,




 "Transportable  Continuous  Emission  Monitoring  System  Operational  Protocol:




 Instrumental Monitoring  of S02, NOX,  C02,  and  02 Effluent  Concentrations."








 SAMPLING PROCEDURE






     To eliminate the  effects of temporal  variations  of  the  average  effluent




 concentration, all  effluent  measurements must  be normalizd to  a specific point




 in time ('t')  before  the average concentration and percent  difference at each




 traverse  point are calculated;  therefore,  a dual probe system  is  used   to




 measure the  effluent  emissions.  One probe  is used as  a  stationary  reference




 point placed at the stack or duct  centroid  during the stratification  sampling




 period; this probe is used  to  indicate the  temporal  change  of  the  effluent




 concentrations.   The second  probe is used  for sampling at  specified  traverse




 points determined  in  accordance with the  sampling  point criteria  of Paragraph




 3.3.1 of proposed  revisions  to Performance Specification 2, Appendix A, 40 CFR




 60 (Federal  Register,  Vol.  44,  No.  197,  October  10,  1979).    The  monitoring




 system samples at the  reference point,  traverse  point,  reference  point,  etc.,




 sequentially throughout  the  testing period for  3  to 5 minutes  at  each point.




The  monitoring  system is calibrated  with  gases  analyzed  by  the  reference




methods immediately before and after the stratification test.
                                   A-5

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CALCULATION PROCEDURE


     The derivation of the  stratification calculation procedure is based  on two

principle assumptions:

     1.  For  each  traverse  point  x,   there  exists  a  unique  constant  of
         proportionality between the concentrations of the Reference  point and
         traverse point, such that:


                  TX = KXRX                                 [EQ.  1]
       where:     T  = Concentration at traverse point x
                  K  = Proportionality constant for point x
                  R  = Reference point concentration
                   x = 1,  2,  3.  .  .
      This relationship implies that:
                        T
                  K  = _L                                  [EQ. 2]
                   X    R
     2.  All changes in effluent concentration occur in such  a  manner that the
         average  concentration  for  a  given  measurement  time  interval  is
         approximately  equal  to  the average  of  the  concentrations  measured
         before and after that measurement time interval.

         Thus, the average reference concentration at  a  time  when the traverse
         point concentration is being measured is equal  to the average  of the
         reference concentrations measured before  and  after  the traverse point
         concentration measurement.


                 Rx ' Rxab = Rxb + Rxa                     ^Q. 3]
        where:  R .  = Reference concentration before  measurement
                 x    of traverse point x

                R   = Reference concentration after measurement
                      of traverse point x

          In  order  to  compare  one  traverse  point  measurement to  another on  a
          consistent basis,  the effect  of effluent  concentration changes  with
          time   must  be   eliminated.    Consequently,   all   traverse   point
          measurements must be  normalized  to  some benchmark  reference  time,  t.
                                    A-6

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        Txn - KxRt

        ^xn = normalized value of concentration for point x

         K  = proportionality constant, defined in EQ. 2

         R  = Reference concentration at reference time, t


Equation 4  results in  the  value that  would have  teen measured  for
traverse point x if the reference concentration had been equal to R,.
                                                                   b

Combining EQ.  2 and EQ.  4 and  simplifying  the  resultant  normalized
concentration is:

             T
 Changes in effluent flow rate or  other  process operating parameters,
 such as failure  of a fan, could  cause  changes in the nature  of any
 stratification present.  This  could  cause  the K  values  to change,
 rendering normalized traverse concentration inaccurate.   Again, this
 is only a  problem if  stratification does  exist,  and the  test will
 "still  detect  this stratification, although it  will  not  accurately
 quantify it.

 The second assumption may provide a more likely reason for inaccurate
 indications  of  the  magnitude   of   effluent   stratification.   This
 assumption is valid only if the sampling time for each traverse point
 is   small  compared    to   any   cyclic   changes   in  the   effluent
 concentrations, or if the magnitude of these changes in concentration
 is small.   As changes in concentration become  larger,  the  assumption
 that:
 becomes  more  critical.    Errors  in  this  assumption  become  more
 pronounced as  the  measurement  time  period  approaches one-half  the
 time period of a cyclic concentration change.  The most likely result
 of such  errors is an  overestimation of  stratification.   Thus,  the
 previously   discussed   stratification   test  procedure   will   err
 conservatively, and indications  of no  stratification can be  viewed
 with a high level of  confidence.
                          A-7

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                                 STRATIFICATION DATA SHEET
Source and Location
Temporal Change
      Reference Probe
Traverse Pro.bc.
                                                             7/////////A

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         APPENDIX B.

REFERENCE METHOD PROCEDURES -

     Reference Method  3

     Alternative Method  for
     Stack Gas Moisture  Dsterraination

     Reference Method  6

     Reference Method  7

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 VETHOD  3—Ot.i  AVALTW  ro»  PtRnosi  DIOXIDI,
  OXTIJKV, Excn» AIR, AND DKY Moi KI ut..ia WKIOBT

 I. Principle nul Application}
                                     [nation 13 to DA
iv^"/.  ii ^ >iry moier mar **imn Tnnnaiion is to cm
made, either an Or^at or a r"> nte l anal> ?>-r may he u.sed
for the anah --is, fnr c\ct ss air nr i minion rate correction
factor determination, an Orsat anabzer must he u^-d.
  1.2  Applicability. Tins nn ilioil is api'lii-able  for de-
termining O): and o: coiv . Mirations. evcss air, and
dry molecular u» i^lit of 3 Dimple from a gas at ream uf a
fos.-11-fuel coml>ti-lion proces*. The method may also  b«
applicable toother process s» here it has been determined
that compounds other than rej,, o». CO, and mtrngen
(Mi) are not  present in  coi'ccntnuiuiu.  sullkieut  to
altevt the results.
  Other methods, as well .1-5 modifications to the proce-
dure described herein, are <\\M ipplii able (or some or  &U
of the above determination*. K\ imples of s|H>citic meth-
ods and modifications include  ilia  niulti-j^dnt samp-
ling  method  using an ors-at inaljzcr to tni.il) ze indi-
vidual grab sample obtained at each  point. {>) a method
Using CO; or Oj and stoichiunu trie calculation* to deter-
mine dry molecular weight and excess air, ; t> assigning a
value o( 30.0 for dry molevu'ar weight, in  lieu of aciual
measurements. for processes I timing natural i^as, coal.  or
t'll. Thes« methods and niodilio\iu,ns may be used. l>ilt
are subject to the  approval o( Hie Adiinmslrator.

-.  .\pparitui

  As an alteinalive lo Ihe  sampling  ipp.u iins ami i>s-
tenis descnN-*! herein, other -ampling svslems  (eg,
luiuid displ.icement) may t>c u^rd provided such s>;>teni3
aro capable of obtaining  a repn^entafivo sample and
maintaining a constant sainpli'i< rate, and  ire otherwise
capable of yielding  acceptable re-nlts.  I's* of  such
<>':>trtm3 is «uhject to the approval of  the Administrator.
  -I  tirab Sampling ( Floury 3 t).
  -' 1.1   Prohe. The probe should h« m >d« of stainless
-(••el or noro$ihc.rte gl.ixj tuhniK and should be cf^uippfd
with an in--ta*-k or out sT^ick hltrr to  remove paniculate
natter (a  plug of s!o»,i wool is -alisfactory for this pur-
!«)>*) Any O'her material inert to Oi, (JOi, CO. and Ni
-uid resistant to temperature at s.\mpluif{ conditions may
Iw used for the  probe; examples of such material are
iluiainu'ii, copper, ijuurtz glass ami Teiton.
  '2.1 2 Tamp.  A  one-way .Miucere bull), or equivalent,
13  used  to  transport the. gas  Cample  to the analyter,
  J.J  Iniecrited Sampling (Future 3-2).
  22.1   Fiobe A probe such .LS that described m Section
-M I  13 suitable.
   i Mention of trade nam-'S or specific products does not
 constitute  endorsvruent by the Environmental Protec-
 tiun Agency.
   J 2 2  Condenwr. An air-cooled or water-cooled coo-
 oens«r,  or  othej  oocdenser  that will not remove Oa,
 C Oi, CO, and NI. may be used to remove excess raofetur*
 wtuch wcnld InUrfere with the operation of the DumD
 and flow met«r.
   223  Valve. A  nwdle valve  is as«d to adjust sample
 gas flow rate.
   224  Pump. A Irak-frw, dlaphraimi-type pump,  or
 equivalent, is used to transjwrt  sample gas to the flenble
 rag  Install a small surge, tank between the pump and
 jute meier to elijiunate the pulsation eJTcct of the dia-
 phragm pump on  the rotametcr.
   2 2.4   Rate Meter. The rotameler, or equivalent rate
 meter, used  should  be  capable of measuring How rate
 to within ±2 percent of the selected Bow rale \ flow
 rate range of M>0 to 1000 crn'mim is siit-c.-sted.
   •228   Flexible Bftc. Any leak-dee ploslic (t f , Tedlar,
 »t>lar, Teflon) or plastic-coated aluminum (e g , alumi-
 iiiied  Mylar) ba«, or  equivalent,  ha\mg a  capacitv
 rtinsistrnl with  the vlovicd flow rate and time length
 cf the test run, may be nscd. A capacity io the range of
 M to 90 liters is sufe-sted.
  Toleat-check the Lag, connect it tn a wa'er piannmeter
 and pressurize the bag to 5 to 10cm H.-O (2 to 4 in. HiO).
 Allow to stand for 10 minutes. Any displacement in the
 water manometer indicates a leak An alternative leak-
 check method Is to pre.s_«uri7e the bag to 5 to 10cm H-O
 (2 to 4 in. H-O) and allow to stand overnight. A deflated
 ba» indicates a leak.
  22.7  Pressure Oa'ige A water-filled U-tuhe manom-
 eter, or equivalent, of about 28  cm (12 in  ) is used for
 the flexible bag leak-check.
  2.28  Vacuum  Gauge.  A  mercury  manometer  or
 equivalent, of at least 760 mm Ug (.30 in. Hg) is used for
 the sampling train leak-check.
  23 Analysis. For Or sat and Fyrite analyter main-
 tenan<-e and operation procedures, follow the mstructions
 rwommended by  the manufacturer, unless otherwise
 •pecilied herein.
  2 3 1 Dry Molecular Weight Determination. An Onwt
•nalyier or Fyrlle type combustion gas analyzer may be
used.
  232 Emission Rate Correction Factor or Eiresa Air
 Determination. An Orsat analyter must be  used.  For
low COi  (less than 4 0 percent) or high Oi Cgre*t*r than
150 percent) concentrations, the measuring burette at
the Orsat must have at least 0 1  percent subdivisions.

 3. Drj Molteular WtyM Determination

  Any of the three samphng and analytical pro* edures
 described below may be used for determining the dry
 molecular weight.
  8.1  Single-Point,  Grab  Sampling and Analytical
 Procedure.
  3 1.1  The sampling point in  the duct shall either be
 at the ctntroid of the cross section or at a point no clo&er
 to the walls than 1 00 ID (3 3ft), unj««sotherw1» specified
ty the Administrator.
  112  Bet up the equipment as shown In Figure 3-1,
making sure all connections ahead of the analyser are
tight and leak-tree. If an Orsat analyier U used. It  a
recommended tbat the analyzer be leaked-checked by
following the procedure In Section 5; however, the leak-
check is optional.
  3.1 3  Place the probe in the stack, with the tip of the
probe positioned at the sampling point; purge the sampl-
ing line. Draw a sample into the  anal>zer and imme-
diately analyze It for percent COiand percent Ot Deter-
mine the percentage  of the gas  that Is Ni and CO by
subtracting the sum of the percent CO) and percent Oi
from 100 percent. Calculate the dry molecular weight as
indicated in Section 6.3.
  3.1.4  Repeat the sampling, analysis, and calculation
procedures, until the dry molecular weights of any thre«
grab aamplea coffer from their me&a by DO more than
0 3 i 'g-mole (0.3 Iblb-mole). Average these three molec-
ular weighu.  and  report  the  result!  to  the  nearest
0 1 g'g-mole Clblb-mole).
  3 2  Bmgle-l'omt, Intt«rated Sampling and Analytical
Procedure.
  3.2.1   The aampling point in the duct shall be located
as'pecified in section 3.1.1.
  3 J 2  Leak-check  (optional) the flenble bag as In
Section  2.2 6. Set up the equipment as shown in Figure
3-2. Just pnor ta sampling, leak-check (optional) the
train by placing a vacuum gauge at the condenser inlet,
pulling  a vacuum of at  least  250 mm Ug (10 in. Hs>.
plugging the ouilet at the quick disconnect,  and tin u
lurnmKoff thr pump. The vacuum should remain stable
for at '.fast u i minute. Evacuate the flexible bag Connect
the prolie a .d plaee it m the sta< k. »nh the.  tip of the
prol-e posit toned at the sain|-ling point, purge the sampl-
ing line. N>it, coimr< t the l>ag and maWe suic  that, all
eon:i*< t.o'i" are tight and leak free.
  321  Sample at  a constant rate The sampling mil
*hoi.ld be s.nMillaneons with, and for  th*» same loldl
length of lime as  the pollutant eni'ssiu'i rate determina-
tion  C olle* lion of at least 30 liters (1 (K) ft') of sample gas
if reconnie-id*-d.  however,  smaller volumes niay be
COllert*-(j If desired
  3 2 4  Obua-ii one integrated flue gas sample during
efcj h pollutant emission rate determination  Within H
hours after the sample is taken, analvzc ift f«r  percent
I'Oi and peref :t Oi using either an Orsat analyzer or a
Fynte-type combustion gas ana!3 ter  If an Ors-at  ana-
lyzer  is used, it is recommended that the Orsat leak-
«he
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                                              RATE METER
          AIR COOLED
          CONDENSER
PROBE
       FILTER
     (GLASS WOOL)
                                             QUICK DISCONNECT

                                                        Jl
                                    RIGID CONTAINER
                         Figure 3-2. Integrated gas-sampling train.
TIME




TRAVERSE
PT.




AVERAGE
Q
1pm





% DEV.a





                             8*9
                                          (MUSTBE<10%)
                     Figure 33. Sampling rate data.
                             Ill-Appendix A-15
                                         B-3

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   IAS Repeat the analysis and calculation procedural
 until the individual dry molecular weights for any three
 analyses differ from their mean hy no mor« than 03
 g/g-mole (0.3 Ib/lb-mole). Average these three molecular
 weights, and report the results to the nearest 0.1 «/g-mol«
 (01 Ib/lb-mole).
   3 »  Multi-Point, Intefralcd Sampling and Analytical
 Procedure.
   1.3.1 Unless  otherwise  specified by  the  Adminis-
 trator, a minimum of eight traverse points shall be used
 tor circular stack* having diameters less then 0.61 m
 (24 In.), a minimum of nine shall be used for rectangu'.ar
 stacks having equivalent  diameters  less than 0.81 m
 (24 in.), and a minimum of twelve traverse points shi 11
 be u*d for all other caws. The traverse points shall he
 located according to Method  1. The use of fewer point*
 is subject to approval of the Administrator.
   3.3.2 Follow the procedures outlined in Sections 3.!.3
 through 3.2.5, eicept for the following- traverse all sam-
 pling points and sample at each point for an equal length
 of lime. Record sampling data as shown in Figure 3-1
 a. Emlaion Kale Corrtditn Factor or Eteat A* Dtttr-
   Non.— A Fyrlte-typ« combustion gas analyzer is not
 acceptable for eicess air or emission rate correction factor
 determination, unless approved by the Administrator.
 IX both percent COi and percent Oi are measured, the
 analytical results of any of the three procedures given
 below may also be used for calculating the dry molecular
 •weight.
   Each of the three procedures below shall  be used o>i'»
 •» hen specified in an applicable subpart of the standard*.
 The use of these procedures for other purpose* ijjutl lia\ f
 specific prior approval of the Administrator.
   4.1  Single-Point,   Orab  Sampling  and  Anal) I A. J
 Procedure.
   4.1.1 The sampling point in the duct shall »:thcr be
 at the centroid of the cross-section or at a point no C!OMT
 to the walls than 1.00m (3.3ft), unless other* is* spett/ied
 by the Administrator.
   4.1.2 Set  up the equipment a." shown in Figure 3-1.
 making sure all connections ahead of the  analyzes are
 tight and leak-tree.  Leak-check tho  Ors»t anal\,
 for percent C'Oi or percent Oj. If MOMS air is desired,
 proceed as follows- (1) Immediately analyte the sample
 as In Sections 4.1.4 and 4.1.5, for percent COi. Oi, and
 CO; (2) determine the  percentage of  the gas that Is Ni
 by subtracting the sum of the percent COj, percent Or,
 and percent CO from 100 percent,  and  (3) calculate
 percent excess air as outlined In Section 0 2.
   4.1.4  To ensure complete absorption of the COi, Oi
 or if applicable, CO, make repeated passes through each
 absorbing solution until two  consecutive  readings are
 the same.  Several pastes (three or four) slmuld be made
 between   readings.  (If  constant  readings  cannot be
 obtained  after  three consecutive readings, replace the
 absorbing solution.)
  4.1.5  After the analysis  Is completed, leak-check
 (mandatory) the Orsat anal) zer oxice again,  as described
in Section 5. For the results of  the analysis to be valid,
 the Orsal  analyter must pass this leak test before and
after the analysis. NOTE.— Since tins  single-point, gr»h
 sampling and analytical procedure is normally conducted
 in conjunction  with  a single-point, grab sampling  and
 analytical procedure for a pollutant, only ono analyse
 is ordinarily conducted. Therefore, great care must be
 taken to obtain a valid  sample and analysis. Although
 in most case* only COi or Oj  is required.  It is recom-
 mended that both COi and Oj be measured. and that
 Citation ft in the Bibliography be used to validate the
 analytical data.
  4.2  Single-Point, Integrated Sampling and Anfll>lie..l
rrocedurc.
  4.2.1 The sampling point in  the duel sh.i',1 I* IG..U..I
as specified in Section 4.1.1.
   4.2.2  Lnik-fhi-ck ImandatorO the iVjiblc h.ig ,i~ m
 fVcllon 2 2 e>. Set up the equipment as iho»n ,n Figure
 3-2. Jiisl prior to sampling, leaL-clm-k inmndatory the
 tram b> placing a vacuum gauge at the oondeibrr inlet
 pulling a vacuum  of at loast 250 mm llg (10 in Hgi
 plugging the outlet at  the  quick disconnect, and •*<•*
 turning off the pump.  The vacuum shall remain stable
 for at least 0 6 minute. Evacuate iru flexible bag. Con-
 nect the probe and plac* it in the stark, with the up of the
 probe positioned at the sampling point, purge the w
 pling  line. Neit, connect the bag and make sure in..:
 all connections are tight and leak free.
   4.2.3 Sample at a constant rate, or as specified by the
 Administrator. The sampling run mnst be simultaneous
 with, and for the same total length of time ae, the pollu'-
 aut  emission rate  determination.  Collect at least  SO
 liters (1 00 ft1) of sample gis  Smaller volumes  may be-
 collected, subh-ct to approval of the Administrator.
   4.2.4 Obtain one integrated flue gas  sample  dtinne
 each pollutant emission rale determination. Kor emission
 rate correction factor deleruinutioti, anahzc the  sanipl.*
 within 4 hours after it is taken fur peieent  CO: or penvri
 Oj (as outlined in  Sections 4..' 5 throuch 4 2 71.  Th-
 Orsat  anah zer must  be  lejik-rhecbed i.
 or If applicable. CO, make repealed passes tlirnnyn ta- li
 absorbing solution until two cimst-cume rea-lmg- an  H.e
 same  Several passes tthree  nr four> shonUI N- n.tvl-  N-
 tween  readings Of constant n a three anal).-e.-- difl r,-i nt by volume wiien COi
 is lew than or equal to 4 0 (>er\ ent. Average the three ac-
 ceptable values of percent t_ Oi and report Ui* result* W
 Uie nearest 0 1 percent.
  4.2 6.2 For percent O:. repeat the analytical proc«lure
 until the results of any thrr« analjMW  JinVr by uu more
 than (a) 0.3 percent by volume when Oils less than  110
 percent or  (b) 0.2 percent by volume, when Oj is greater
 than 15.0 pen-ent. Aver«<- the three acceptable value." u[
 percent Oi and report the results to the nearest  0.1
 percent.
   4.283 For percent CO. repest the analytical proce-
 dure until  the results of any three analyses dlller by no
 more than 03 percent  Average the three acceptable
 values of percent CO and report the results to the nearest
 0.1 percent.
   4.J 7  After the  anaKsis  is  completed, leak-check
 fmand!itor>) the Orsat anal> zer ome acaui as described
 insertions For the result so'f the anal\s>s  in be valid, the
 Orsat analyzer must pass this lejk ust before and after
 the anal}sis. Note- Although in most instances only COi
 or Oi is required, it is recommended that both CO, and
 Otbe measured, and that Citation 5 in the Bibliography
 b* used to validate the analytical data.
  4.3  Mnlti-l'oiiil, Integrated Sampling and Analytical
 Procedure.
  4.3.1   Both the minimum number of sampling points
and the sampling point location shall be  as specmed in
Section 3 3.1 of this method. The use ot fewer points than
specified ie. Jabject to the approval of the Administrator.
  4.3.2   Follow the procedures outlined in Sections 4.2 2
through 42.7,  eicept  for  the  following: Traverse all
sampling points and sample at each point for an equal
length  of time. Record sampling data as shown in Figure

5. Lmk-Clirck Proudvrt for fatal Analyzm

  Moving an  Orsat analyzer frequently causes It to leak.
Therefore, an Oraat analyzer should be thoroughly leak-
checked on site before the flue gas sample is introduced
into it. The procedure for leak-checking an Orsat analyzer
it:
  5.1.1  Bring the liquid level In each pipette up to the
reference mark on the capillary tubing and then close' thn
pipette stopcock.
  5.1.2  Raise the leveling bulb sufficiently to bring the
confining liquid  meniscus onto the graduated portion of
the burette and then close the manifold stopcock
  5.1.3  Record the meniscus position.
  5.1.4  Observe  the meniscus in  the  burette and the
liquid level In the pipette for movement over the next 4
minutes.
  5.1.5  For the Orsat analyzer to pass the leak-check
two conditions must be met.                         '
  5.1.5.1  The liquid level  In each pipette must not fall
b«low the bottom of the capillary tubing during this
4-mi nute i nterval.
  5.1.5.2  The meniscus In  the burette  must not change
by more than 0.2 ml during this4-mlnutelnterval
  5.1.«  If the analyzer fails the leak-check procedure  all
rubber connections and stopcocks should be checked
until the cause of the leak is identified. Leaking stopcocks
must  be disassembled, cleaned, and  regressed. Leaking
rubber connections must be replaced. After the analyzer
U  -eassembled,  the teak-check  procedure must  be
repeated.

8. Calculation*

  8.1   Nomenclature.
     Mi—Dry molecular weight, g/g-mole flb/lb-mole).
   %EA = Percent excess air.
  %CO-= Percent COi by volume {dry basis).
    %Oj- Percent Oi by volume (dry basis).
   <7oCO-Percent CO by volume 'dry basis).
    %N;=-Percent Ni by volume (dry basis).
    0264 = Ratio  of Oi to Niin air, v/v
    0.2^1 = Molecular weight of NI or CO, divided by 100
    0.320 = .Molecular weight of Oi divided by 100.
    0440-Molocular weight of COj divided by 100.
  8.2   Percent Eicess Air.  Calculate the percent  eicess
air (if  applicable),  by  substituting  the  appropriate
values of peicent O-, CO, and N'i (obtained from Section
4.1  3 or 4 2 4) into Equation 3-1.
I = [rl2
                   %0,-0.5%CO         '
              264 %N, ( %0,- 0.5 %'CO).
100
                                    Equation 3-1

  NOTE —The equation  above assumes that ambient
air Is used as the source of Ot and that the fuel does not
contain appreciable amounts of Ni (as do coke oven or
blast furnace ga-ses). For those cases when appreciable
amounts of Ni are present (coal, oil, and natural gas
do not contain appreciable amounts of N,)  or  when
oiygcn enrichment is used, alternate methods, subject
to appruval of the Administrator, are required.
  6 3   Dry  Molecular  Weight  Use  Equation 3-2 to
calculate the dry  molecular weight of  the  stack gas
                                    Equation 3-2

  NOTE — The above equation does not consider argon
In air  (about 0 9  percent, molecular weight of 37 7).
A negative  error of about 04 percent is Introduced.
The tester may opt to include argon in the analysis using
procedures  subject  to approval of  the  Administrator.

7. Bittlioyraphy

  1. Altshuller. A. P. Storage of  Oases and  Vapors in
Plastic  Bags. International Journal of  Air and Water
Pollution. 6.75-81. 1963.
  2. Conner, William D. and J. B. Nader. Air Sampling
Plastic  Bags. Journal of the  American  Industrial Hy-
giene Association. IS -291-297. 1964.
  3. ^urrell Manual for Oas Analysts, Seventh edition.
Bun-ell  Corporation,  2223 Fifth  Avenue, Pittsburgh,
Pa. 15219 1S51.
  4. Mitchell, W. J. and M. R. Midgett. Field Reliability
of the Orsat Analyzer. Journal of Air Pollution Conuol
Association K 491-495. May 1978.
  5. Shigehara, R. T., R. M. Neulicht. and W. S. Smith.
Validating Orsat Analysis Data from Fossil Fuel-Fired
Units. Stack Sampling News. 4(2)21-2«. August,  1978.
                                                             Ill-Appendix  A-16
                                                                                  B-4

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                 AN  ALTERNATIVE METHOD FOR

              STACK GAS MOISTURE DETERMINATION
                                             «
             Jon Stanley and Peter R. Westlin
Introduction

     Reference Method  4  "Determination of  Moisture  Content
in  Stack  Gases"   in  Appendix  A  of  Title  40  CFR  Part  60,
Standards   of   Performance   for   New  Stationary   Sources
describes two  sampling metnods - a  reference  method  an  an
approximation  method.    The   reference   method   employs
Smith-Greenburg impingers  whereas the  approximation  method
uses midget  impingers.   A  study  was  conducted  to  determine
if  the  approximation  method sampling  train   and  procedure
could be modified and  be used  as  an  alternative method.  In
addition, a  similar  study  was conducted with  the  Reference
Method  6  train  to  determine  if  the  procedure  could  be
modified to  simultaneously  measure  moisture  content  and S02
concentration .
     Test results  showed  that the midget  impinger  sampling
train can be used for accurate moisture determination.  This
paper  describes  the  two  alternative moisture  measurement
methods  and  presents a  summary  and  analysis of  results  of
the field tests with the methods.
Test Method

1.  Apparatus.  The sampling equipment  is  the  same  as spec-
    ified for the moisture approximation method in Reference
    Method  4 and  in  Reference  Method  6,  except  for  the
    addition of a  silica  gel trap.  (See  Figures 1  and  2.)
    The silica gel trap is a midget  bubbler  with  a  straight
    tube.
   Emission  Measurement   Branch,   Emission   Standards  and
Engineering  Division,  Office  of  Air  Quality  Planning  and
Standards,   Environmental   Protection   Agency,   Research
Triangle Park, North Carolina 27711, August,   1978.
                               B-5

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2.   Reagents
         For the modified approximation Method  4,  add  10 ml
         of water  to  each of  the  first  two  impingers  and
         approximately 15 g of silica gel  in the bubbler.

         For the modified  Reference  Method  6  train,  add 15
         ml of 8 percent isopropanol  to the first impinger,
         15 ml  of  3 percent  hydrogen peroxide in  the  next
         two impingers,  and approximately  15 g of silica gel
         in the final  bubbler.
3.   Procedure
     a.   Apply silicone grease  as necessary -to  the  ground
         glass fittings of  the   impinger  halves.   Wipe  any
         extra grease from the  ball  joint fittings  and  the
         outside   of  the  impingers   and  weigh   all   the
         impingers at one  time   to the  nearest  tenth  gram.
         Record the weight.

     b.   Assemble the train as  shown  in  Figure  1  or  Figure
         2.

     c.   Perform   a  leak check  by disconnecting  the  first
         impinger  from  the  probe  and,   while  blocking  the
         impinger inlet, activating the  pump and opening the
         needle valve.   An  acceptable  leak check is achieved
         when the rotameter indicates no  flow,  the  dry  gas
         meter is stationary  for one  minute,  and bubbling in
         the  impingers  is  limited to less  than  one  bubble
         per second.  Release  the impinger inlet plug slowly,
         turn off the pump,  and  reconnect the  probe.

     d.   Read and record the  dry gas  meter volume.  Ice down
         the  impingers  and  heat  the  probe  as  necessary.
         Read and record the  barometric  pressure.

     e.   Start the sample pump  and  adjust the  sample  flow.
         Maintain  the  flow  for  the  modified  approximation
         Method  4  between  1  and  4  1pm  and   the  flow  for
         Reference Method  6  at 1 1pm.

     f.   Continue the sampling  for  twenty minutes  or  other
         approximate  sampling   time.   (The  total  moisture
         catch  must   be  at   least  1.0   gram  to  maintain
         measurement  accuracy.)  Read  and  record  the dry gas
         meter temperature  every  five   minutes   during  the
         sampling run.

     g.   At  the  end  of  the sample  run,   stop  the  pump  and
         record  the  final  dry   gas  meter  volume  reading.
         Conduct  a leak  check  as specified in  Part 3c.
                             B-6

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      Heated Probe
                                    Silica Gel Tube

Filter (Glass Wool)
             Ice  Bath      Midget  Irapingers
    Valve    |i|/Rotameter

X         sr
i    .=..  4'
     V	r
    Pump    Drv Gas Meter
               Figure 1.  Modified Approximation Method 4 Train
                                        Silica Gel Tube



                                                 Valve
               !/
                   Rotameter
  Filter (Glass  Wool" wLjil
                       Midget  Impingers
              Figure 2.  Modified Reference Method 6 Triln for
                         Kofsture Determination
                                             B-7

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     h.  Remove the  impingers from  the  ice bath,  cap  them
         and allow them to warm to ambient temperature.

     i.  Wipe any  excess  moisture from  the outside  of  the
         impingers and reweigh them  in  the manner specified
         in Part 3a.
Calculations
     The following  are  the  calculations  used  to  determine
the moisture content of the stack gas:
     (1)
                 V.,,, =  1.336 x  10~3   W
                  W G
     Where:   VWQ = Volume of water vapor condensed, corrected to
                    standard condtions, scm.
     (2)

     Where
                W = Total weight gain of the condenser and silica
                    gel trap assembly, g.
                 m
                  std
                      = °-3855 Y
                                        m
                                   m
               Dry gas volume measured by meter,
               corrected to standard conditons,
               d scm.
                    Y = Meter calibration coefficient,
                        d imensionless.
                   P  = Absolute meter pressure,  in. Hg.

                   T  = Absolute temperature at meter,  K.

                   V  = Dry gas volume measured by meter,
                        dcm.
     (3)
Where:
                              we
                                     x 100
                              ws
                                   V    +
                                    we
                                            std
                         = Water vapor content in stack gas,
                           percent.
Discussion and Summary of Test Resu11s
     A  series  of  test   runs   was  completed   using   the
procedures described  in  the  paper  on  the  exhaust  of  a
gas-fired incinerator.   Initial tests were made using trains
based on the condensation  principle of  Reference  Method  M,
but using midget  irapingers and up to  three  silica  gel  traps
in each  train.   An  evaluation of  these  extra  silica  gel

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traps   showed   that   complete   (> 95   percent)   moisture
collection was possible with the condenstation train and one
silica gel trap.  An error analysis showed that the moisture
collection must be  at least  1  g  to  maintain  the  absolute
accuracy required  of the method (see Recommendations).

     Each test  run  consisted of  two  identical  test  trains
(except Run MA-19) operated  simultaneously,  and the results
were  calculated  from  data  collected  by  each  train.   The
repeatability of the results was determined by comparing the
results of the two trains run side by side.  Table  1  shows  a
summary  of  the  test   results  which   includes   a   brief
description of the trains for each run.

     Analysis  of  the  results  shows  that  either  modified
moisture  method  is   precise,  can  be  used with  no loss  of
accuracy, and can  be used as an alternative moisture method.
Of the thirteen duplicate runs shown in Table 1, all but one
yielded _+ 0.5  percent  absolute  agreement or  better  between
the results of the paired trains.

Error Analysis

     The minimum moisture catch should be at least 1  g  to
assure accurate results.  An  error  analysis  illustrates the
importance  of  the   recommendation.   For  example,  for  a
moisture weight gain of  0.60  g, a balance with  an  accuracy
of _+ 0.05 g  could produce results^ between 0.55  and  0.65  g.
For  a  gas volume  of  1.51  x  10~   dscm,   these  two  values
correspond  to   moisture   levels  of  4.6  and  5.4  percent,
respectively.  Sampling the same  stack  gas until 1.0 g  was
collected would require 2.54  x  10~  dscra of  sample gas.   A
similar measurement  error of  _+  0.05 g in the  sample  weight
gain  would  produce  moisture  levels  between  4.8  and   5.2
percent.
References

     40 CFR 60, Standards of  Peformance for  New  Stationary
Sources, Federal  Register.  Vo.  42,  No.  160,  August 18,  1977.
                             B-9

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                                           TABLE 1.  SUMMARY OF RESULTS
          Run
         Number
          MA-2
Flow
Rate
(1pm)
 Moisture
Calculated
   from
  Train 1
 (Percent)
              3.6
 Moisture
Calculated
   from
 Train 2
(Percent)
                  4.1
l)i I ference
Descri ption
    of
   Tra i its
                                  1 water impinger
                                  3 silica gel traps
          MA-6
              7.6
                  8.0
                  0.4
                  2 water impingers
                  2 silica gel traps
CO
I
O
          MA-7
          MA-8
              7.1
              5.9
                  7.2
                  6.0
                  0.1
                  0.1
                  2 water impingers
                  2 silica gel traps
                  2 water impingers
                  2 silica gel traps
          MD-9
              6.7
                  6.6
                  0.1
                  2  water impingers
                  2  silica gel traps
          MA-10
              6.0
                  5.9
                  0.1
                  2  water impingers
                  2  silica gel  traps
          MA-12
          MA-14
          MA-15
              6.4
              5.2
              4.8
                  6.3


                  5.2


                  4.9
                  0.1
                  0.0
                  0.1
                  2  water  impingers
                  2  silica gel  traps

                  2  water  impingers
                  2  silica gel  traps

                  2  three  percent  perox  impingc.rs
                  2  silica gel  traps

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         Run
        Number
Flow
Race
(1pm)
                                          TAIlLli  I .  SUMMAKY Ol-'  UIISULTS
                                                   (Continued)
 Moisture
Calculated
   from
  Train 1
 (Percent)
 Moisture
Calculated
   from
 Train 2
(Percent)
                                                                  I icrence
   Uescr i pLion
       ot
      Tr.i i us
DO
i
        MA-16
         MA-17
         MA-18
         MA-19
              6.6
              6.9
              4.8
              6.4
                  6.5
                   5.1
                   4.9
                  6.6
                                                                   0.1
                    1.8
                   0.1
                  0.2
2 three percent peroxide
impingers
2 silica gel traps

2 three percent peroxide
impingers
2 silica gel traps

1 80 percent isopropanol
irapinger
2 three percent peroxide
impingers
1 silica gel trap

Train 1
 1 80 percent  isopropanol
 impinger
2 3percent  peroxide  impingers
1 silica gel trap

Train 2
 2 water impingers
 2 silica gel  traps

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MLTHOD  6—DETERMINATION  or  SVLFI s   !>i,jvr E
        EMISSIONS FROM BIATIO.\*R\  bunt'ia

1. Principle and Applict/iiiit}

  1.1   Principle.  A gas sample is extra--lod froui  tl e
sampling point in the stack.  Tbe  sulfuric aud misi
including sulfur tnoxide) and the sulfur dioxide  are
separated. Tbe sulfur dioxide fraction is  measured by
Viie barium-tborin utratiou method.
  1.2   Applicability. This method is applicable for  the
determination of sulfur dioxide emissions trom jtationary
sources. The minimum detectable limit o( the method
has been determined to be 3 4 milligrams (mg\ of SOt'm1
(2.12X10-' Ib'fi'). Although no upper lumt  has been
established, tests  have shown that concentrat'ons as
high as 80.000 mg'm'  of SOi  can be collected etucl'-ntly
in iwo midget impingers, each containing 15 milliners
of 3 percent hvdrogen peroxide, at a rate  of I 0 !pm for
20 minutes. Based on IheorciKal calculations, the upper
concentration limit in a '."O-hter sample is about 93,300
rug ID'.
  Possible interft'rents are  free ammonia,  water-soluble
canons, and  fluorides. Tbe  cations and  fluoridts  are
removed by glass wool filters and an isopropanol bubbler.
and he-nee, do not affect the SO; analysis. >A lien samples
are being taltrn from a gas stream with hiph concentra-
tions of very  line metallic fumes  (such as in  mlcu to
control devices), a hich-eincsrncy glass hl>er filter man
be used HI place of the glass  wool  pin; u  e , the one in
the probe^ to remove  the cation intcrfuent*.
  Free anuuonia uuerft-rrs hy reacting »ith SOj (o form
particulate sulfite and by  reacting with the indicator
If free aromoma is prestnt (this can be delrrmined by
knowledge of the process and noticing white nuuculaie
matter in the probe and isoproi>anol bubble:\ alterna-
tive methods, subject to the approval of the AdTum:str»
tor,  U.S.  Enviroiinn ntal  I'roKMion  Apency,  ar«
re<)mr«0.

2. 4pparotut
  11   Sampling. The sampling tnln U shown m Figure
ft-1, and component parts are discussed below. The
teeter  has the option of substituting  sampling equip-
ment described In Method 8  m Place of the midget  im-
pinger equipment of Method  6. However,  the Method 8
train must be  modified to include a heated niter between
the probe and isoprppanol  Impinger, and  the operation
of the sampling train and  sample analysis must be at
toe flow rates and solution volumes denned in Method 8.
  The  tester  also has the option of determining  3Ui
atznultaneously with  paniculate matter and  moisture
determinations by (1) replacing the water in a Method 5
Impinger system with 3 percent pehoude solution, or
(2)  by replacing the  Method 5 water impinfcer system
with a Method 8 i*opropanol-nlter-peroiide system. The
analysis for 8Oi must be consistent with the procedure
In Method 8.
  2.1.1  Probe. Borosilicate glass, or stainless steel (other
materials of construction may be  used, subject  to  the
approval  of the Administrator), approximately 6-mm
Inside  diameter, with  a heating system  to prevent water
condensation and a filter (either In-slack or heated out-
(tack)  to remove paniculate  matter, including sulfunc
add mist.  A plug of  glass wool is a satisfactory filter.
  2.1.2  Bubbler and  Lmplngers. One  midget  bubbler,
with medium-coarse glass frit and borosillcate or quartz
(lass wool packed in top  (see Figure »-l) to prevent
sulfunc acid mist carryover, and three 30-ml midget
Unpmgers. Tbe bubbler and midget impingers must be
connected in series with leak-free glass connecton. Sili-
eone (Tease may be used, if necessary, to prevent leakage.
  At the option of the tester,  a midget impinger may be
toad in place of the midget bubbler.
  Other collection absorbers and flow rates may be used,
but are subject to the approval of the Administrator.
AJao, collection efficiency must be shown  to be at least
99 percent for each test run and must be documented in
the report. If the efficiency is found to be acceptable alter
a aeries of three  tests, further documentation  is  not
required. To conduct the  efficiency test, an extra  ab-
sorber must be added and  analyzed  separately. This
mrtra  absorber must not contain more than 1 percent of
UM total SOi.
  n,»  Glass Wool.  Boroellfcate or quartz.
  S.1.4  Stopcock  Oreaae.  Acetone-insoluble,  heat-
stable slllcone grease may be used, If neceseary
  1.1.5  Temperature  Oaufe.  Dial thermometer, or
equivalent, to measure temperature of gas leafing im-
 pinger train to within 1* C  (2* F.)
   1.1.6  Drying Tub*. Tub* packed with ft- to lo-meab
 Indicating type silica (el, or equivalent, to dry the gas
 sample and to protect the meter and pump. U the stllac
 (el has been used previously, dry at 175*  C (350° F) for
 2 noun. New silica (el may be used as received. Alterna-
 tively, other types of desiccants (equivalent or better)
 may be used, subject to approval of the Administrator.
   11.7  Value. Needle value, to regulate sample gas  flow
 rate.
   2.1.8  Pump. Leak-free disphragm  pomp,  or equiv-
 alent, to pull gas through the train. Install a small tank
 between the pump  and  rate meter  to  eliminate the
 pulsation effect of the diaphragm pump on the rotameter.
   2.1 9  Rate Meter. Rotameter,  or equivalent, capable
 of measuring flow rate to within 2 percent of the selected
 flow rate of about 1000 cc/mln.
  2.1.10 Volume  Meter.  Dry gas  meter,  sufficiently
accurate to measure the sample volume within 2 percent.
calibrated at  the selected flow  rate  and  conditions
actually encountered  during  sampling, and equipped
with a temperature gauge (dial thermometer, or equiv-
alent)  capable ol measuring  temperature  to  within
S°C (5.4-F ).
  2.1.11 Barometer. Mercury,  amerold, or other barom-
eter capable of measuring atmospheric pressure to within
2.4 mm Hg (0 1 in Hg). In many cases, the barometric
reading ma>  be obtained from a nearby national weather
service station, in which  case the station value (which
is the absolute barometric pressure) shall be requested
and  an adjustment for elevation  differences between
the weather station and sampling point shall  be applied
at a rate of minus 2.5 mm Hg (O.lin. Hg) p*r30m (100ft)
elevation increase or vice versa for eievation decrease
  2.1.12 Vacuum Gauge. At least 760 mm Hg (30 in
Hg)  gauge, to be used for  leak check of the sampling
train.
  2.2  Sample Recovery.
  2.2.1 Wash  bottles. Polyethylene or (lass,  500 nil.
two.
  2.2.2 Storage Bottles. Polyethylene, 100 ml, to store
Impmger samples (one per sample).
  2.3  Analysis.
  2.3.1 Pipettes. Volumetric type, 5-rnl, 20-ml  (one per
sample), and 25-ml sues.
  2.3.2 Volumetric Flasks. 100-ml site (one per sample)
and 100-ml site.
  2.3.3 Burettes. 5- and 50-ml  slies.
  2.3.4 Erleniaeyer Flasks 250 ml-elee  (one for each
•ample, blank, and standard).
  2.3 5 Dropping Bottle  125-ml sin", to add Indicator
  2.3 « Graduated Cylinder 100-ml sue.
  2.3.7 Spectropbotometer. To measure absorbance at
852 nanometers

3. Recent*

  Unless otherwise indicated, all reagents roust conform
to the specifications established by the Committee on
Analytical Reagents of the American Chemical Society
Where such specifications are not available, use the best
available grade.
  3.1   Sampling.
  3.1.1  Water. Detoniied, distilled to conform to ASTM
specification D1193-74, Type  3. At the option  of 'he
analyst, the KMnOt  test for oxlditable organic ma'l'-r
may  be omitted when high  concentrations of orgi>r.u
matter are not expected to be present
  312 Isopropanol, 80 percent Mu SO inl of isopropanol
with 20ml of deionited distilled water. Check each let of
Isopropanol for peroxide  impurities as follows  shak,' 10
ml of isopropanol with  10 ml  of freshly prepared 10
percent potassium Iodide solution Prepare a blank by
similarly treating 10 ml of distilled water After 1 minut*.
read  the  absorhance  at  2A2 nanometers on a spectro-
photometer If absorbance  exceeds 0 1,  reject alcohol for
use
   Peroxides may be removed from isopropanol  by redis-
tilling or by  passage through a  column of activated
alumina;  however,  reagent   grade  isopropanol  witli
suitably low peroxide  levels may be obtained from com-
mercial sources.  Rejection of contaminated lots may,
therefore, be a more efficient procedure
  1.1 3 H>drojten Peroxide, 3  Percent. Dilute 30 percent
hydrogen peroxide 1  9 (v,v)  with deionized.  distilled
water (30 ml is needed per  sample)  Prepare  fresh  dally
  314  Potassium Iodide Solution, 10 Percent  PlssoUe
10 0 grams KI in deionited. distilled water and dilute to
100 ml Prepare  when needed.
  1 2  Sample Recovery
  121  Water. Deionited, distilled, as in 3 1  I.
  122 Isopropanol. 80 Percent Mu SO ml of isopropano'
with 20 ml of deloniied, distilled water
  3.3  Analysis
  t 3.1 Water. Deiomwd, distilled, as in 3 1.1.
  3.3 2 Isopropanol, 100 percent
  S3 3 Thorln    Indicator    l-(o-arsonophenylaioi-2
naphthoM.ft-disulfomc acid, jdi sod mm salt,  or equiva-
lent. Dissolve 0.20 g in 100  ml  of deionited, distilled
water.
  334 Barium  Perchlorate  Solution,  00100 N  Dis-
 solve 1 95 g of barium  perchlorat* tnhydrate [Ba(ClO.h
IHrO] In 200 ml distilled water and dilute to 1 liu-r with
  sopropanol  Alternatively. 1 22 g of [BaClr2H-O] nia\
be used instead of the  perchlorate  St&ndardite as in
 Section 5.5.

   335  SuUurlc Acid Standard, 0 0100 N.  Purchase or
  standardize to »0 00112 N against 0 0100 N NaOH which
  has previously been standardized against potassium
  acid phthalate (primary standard grade)

  4. ProcnJurf.

   4 1 Sampling.
   4 1 1  Preparation of collection train. Measure 15 ml of
  80 percent  isopropanol into the midget  bubbler  and 15
  ml of 3 portent hydrogen  peroxide into each of the first
  two midget impmgers  Leave the final midget impinger
  dry Assemble the train as shown In Figure 6-1   Adjust
  probe heater to a temperature sufficient to prevent » ater
  condensation. Place  crushed  tee and water around the
  impingers.
  4 1 _  Leak-check procedure  A 'efllc check prior to th«s
Campling run is optional however, a tenlc chevk after the
sampling mn is rrandstory The !eakist JO  seconds. Cirefu'.'y  release the
vacuum gauge before releasirg the .lew rr.eter end to
prevent ba»'k Mow of the ir-ip. ^ger fVud
  Other leak check  procedures '".ay '?* used, subject to
the approval of the  Administrator. U 3  Environmental
Protection  Agency  The procedure used in Method 5 is
not suitable for d.aohragm pump*
  413  Sample collection  Record  the  ir.itial dry gas
meter reading and  barometric  pressure  To begin sam-
pling, position the tip of the probe at the ?amphng point,
connect the probe to the bubbler, and start  the pump
Adjust  the sample now  to  a constant rate  of ap-
proximately 1 0 I'.ter mm as indicated hy the rotameter
NUmtain this constant rate (*10 percent) during the
en'ire  sampling run  Take readings fdry gas  meter.
temperatures at dry gas meter and at impinger outlet
arc! rate meter) at least every 5 minutes Add more ice
during the nin  to  keep the tempt-rature of the gases
leaving the. last Impinger at yf C '-£? F) or less  At the
conclusion of each run, turn off the pump, remove probe
from the stack, and record the  V.al readings  Conduct  a
leak check as m Section 4 1 2 vThis >at cbect is nianda-
tory ) If a leak .5 found, void the te5t run Drain  the Ice
hath, and purge the remaining  part of the train by draw-
ing c'ean amb'ent air through :he system 'or  15 minutes
at the sampling rat*
  Clean ambient air can be  prowled  by passing  air
through a  charcoal filter  or  tS.ro'ix1! an ex'.ra midget
fmpin^er with 15 ml of 3 percent H.Ch The  tester may
opt to simply -;?e ambient -i^r,  without purification.
  42  sample Re< ovry  Disconnect the impir.
-------
  5.2  Thermometers.  Callbrat* against mercnry-tn-
glasa thermometcn.
  5.3  Rotameter. The rotameter need not be calibrated
but should be cleaned and maintained according to the
manufacturer's instruction.
  5.4  Barometer. Calibrate against a mercury barom-
eter.
  5.5  Barium Perchlorate Solution.  Standardite  the
baritim perchlorate solution against 25 ml at standard
sulfonc acid to which 100 ml o[ 100 percent isopropanol
has b«ea added.

  8. Calculation*

  Carry out  calculation],  retaining at least one extra
decimal figure beyond that of the acquired data.  Round
off figures after final calculation.
  0.1  Nomenclature.

    C> —Concentration at sulfur dioxide,   dry basis
          corrected to standard conditions,  mg/dscm
       .   (lb/d*cf).
      .V> Normality of  barium  perchlorste tltrant,
          mllllequivalents/ml.
    Pi,,,"Barometric pressure at the exit orifice of the
          dry gas meter, mm Hg (in. Eg).
    PttdmStandard  absolute  pressure, 700  mm  Hg
          CS.fila. Hg).
     T." Average dry gas meter absolute temperature,
          °K(°R).
     T.id - Standard  absolute  temperature,  293*   E
          1528° R).
      V% >• Volume of sample aliquot titrated, ml.
     V.-Dry gas volume as  measured by the dry gas
          meter, dcm (dcO.
                                                 V.(nj)-Dry gw  volume measured by the dry gat
                                                         meter,  corrected to  standard  conditions,
                                                         dscm (dscf).
                                                   V—i.— Total volume of solution In which the sulfur
                                                         dioxide sample is contained. 100 ml.
                                                      Vi«Volume of barium perchlorate tltrant  used
                                                         for  the sample, ml  (average of replicate
                                                         tltratlons).
                                                     Vn^Volume of barium perchlorate tltrant  used
                                                         for the blank, ml.
                                                      Y= Dry gas meter calibration (actor.
                                                   32.03= Equivalent weight of sulfur dioxide.
                                                 0.2   Dry sample gas  volume,  corrected to standard
                                                conditions.
                                                                   "4      t»'   _ if v  "
                                                                                    '   ~
                                                                                    Equation 8-1
                                                where:

                                                 K>0 3858 »E/mm Hg for metric unit*.
                                                    -17 84 • R.'ln. Hg tor English units.
                                                 «J  Sulfur dioxide concentration.
                                                                            •(•id)
                                               where'
                                                 Jfi-32.03 mB'meq. for metric oniu.
                                                    -7.0BlX10-«lb/rae
-------
METHOD  7—Dm«xn«iTToN or NmooEX  OXIDE
       EMISSIONS FKCM STmoNiar Souxcis

1. PrindfU mt Apfllataur

  1.1  Principle. A grab sample is collected in an evacu-
ated flask containing a dilute sulfurte  acid-hydrogen
peroxide absorbing solution,  and the nitrogen oxides,
except  nitrous oxide, an  measured  colonmetericsUy
using the pher.oldisulfonlc acid (PDS) procedure.
  1.2  Applicability.  This method is applicable to the
measurement of nitrogen oxides emitted from stationary
sources. The range 01 the method has been determined
to be 2 to WO milligrams NO,  (as NOi) per dry standard
cubic meter, without oaring to dilute tee sample.

2-Xpparorw

  XI  Sampling (set Figure 7-1). Other grab sampling
systems or equipment, capable of measuring  sample
volume to wUhm ±2.0 percent and collecting a sufficient
sample volume to allow analytical reproducibility to
within ±5 percent, will be considered acceptable alter-
natives, subject to approval of the  Administrator, U.S.
Environmental  Protection  Agency. The  following
equipment is used in sampling:
  2.1.1  Probe. BoroaUlcate glass  tubing, sufficiently
heated to prevent water condensation  and equipped
with an in-stack or oat-stack niter to'remove particulate
matter (a plug of  glass  wool is  satisfactory for  this
purpose). Stainless steel or Teflon ' tubing may also be
used for the probe. Heating Is not necessary if tha probe
remains dry daring the purging period.
  I Mention of trade names or specific products does not
constitute endorsement by the  Environmental Pro-
tection Agency.
      2.1.2  Collection Flask. Two-liter boroslllcat*, round
    bottom flask, with short neck and Z4/40 standard taper
    opening, Protected against Implosion or breakage.
      2.1.3  Flask Valve. T-bore stopcock  connected to a
    24/40 standard taper joint.
      2.1.4  Temperature Qauge. Dial-type thermometer, or
    other temperature gaupe, capable of measuring 1° C
    (2' F) intervals from -5 to 504 C (25 to 125° F).
      2.1 5  Vacuum Line. Tubing capable  of withstanding
    a vacuum of 75 mm Eg (Jin.  Hi?) absolute pressure, with
    "T" connection and T-bore stopcock.
      2.1.6  Vacuum  Gauge.  U-tube manometer. 1 meter
    (3C  in.), with 1-mm (0 1-in.) divisions, or other gauge
    capable of measuring pressure to within  ±2.5 mm Hg
    (010 in. Hg).
      2.1.7  Pump. Capable  of  evacuation the collection
    flask to a pressure equal to or less than 75  mm Hg (3 in.
    Hg', absolute.
      2.1 8  Squeeze Bulb. One-way.
      2.1.9  Volumetric Pipette. 25ml.
      2.1.10  Stopcock and Ground Joint Grease. A high-
    vacuum,  high-temperature chlorofluorocarbon grease Is
    required. Halocarbon 25-5S has been found to be effective.
      2.1.11  Barometer. Mercury, aneroid, or other barom-
    eter capable of measuring atmospheric pressure to within
    2.5 mm Hg (0.1 in. Hg). In many cases, the barometnc
    reading may be obtained from a nearby national weather
    service station, in which case the station value (which is
    the  absolute barometnc pressure) snail be requested and
    an  adjustment for elevation differences between the
    weatht;r ?tat>on and sampling point shall be applied at a
    rate of minus 2.b  mm Hg <0 1 in  Hg) per 30 m (100 ft)
    elevat.on increase, or vice versa for elevation decrease.
      2.2  Sample  Recovery. The  following  equipment is
    required for sample recovery
      2.2.1  Graduated C>linder. 50ml with 1-ml divisions.
      2.2J;  Storage  Containers.   Leak-free  polyethylene
    bottles.
  2.2.3  Wash Bottle  Polyethylene or glass.
  2.2.4  Glass SUrring Rod.
  2.2.5  Test Paper for Indicating pH. To cover the pH
range of 7 to 14.
  2.3  Analysii. For the analysis, the following equip-
ment is needed
  2.31  Volumetric Pipettes. Two 1 ml. two 2  ml, one
I ml, one 4 ml, two 10 ml. and one ^5 ml for each sample
and standard

  2.3.2  Porcelain  Evaporating  Dishes. 175- to 2SO-mi
 capacity with lip for pouring, one for each sample and
 each standard. The Coors No. 45006 (shallow-form, 195
 ml)  has  been found to be satisfactory. Alternatively.
 polymethyl pentene beakers (Nalge No. 1203. 150 ml). or
 glass beakers (ISO ml) may  be used. When glass beakers
 are used, etching ot the beakers may cause solid matter
 to be present in the analytical steo the solids should be
 removed by filtration (see Section 4.3).
  2.3.3  Steam Bath  Low-temperature ovens or thermo-
 statically controlled hot plates kept below 70° C (160°  F)
 ar» acceptable alternatives.
  2.3.4  Dropping  Pipette or Dropper. Three required.
  23 5  Polyethylene Policeman. One  for each sample
 and each standard.
  2.3 S  Graduated Cylinder. 100ml with 1-ml divisions.
  2.3.7  Volumetric Flasks.  50 ml (one for each sample),
 100 ml (one for each sample and each standard,  and one
 lor the working standard KNOi solution), and 10*0 mi
 (one).
  23.8  Spectrophotometer. To measure absorbance at
 410 nm.
  2.3 9  Graduated Pipette. 10 ml with 0 1-ml divisions.
  2310  T«t Paper for Indicating  pU  To cover the
 pH range of 7 to 14.
  2.3 11  Analytical Balance. To measure to within 0.1
 mg.
           PROBE
           A
                                                                                                                         SQUEEZE BULB
          FLASK VALVE'
        FILTER


 GROUND-GLASS SOC

        § NO- 12/5
                  110 mm
  3-WAY STOPCOCK:
  T-BORE. § PYREX.
 2-mm BORE. 8-mm OO
            FLASK
                                                  FLASK SHIELD-. ,\
                                                                             THERMOMETER
              GROUND-GLASS CONE.
               STANDARD TAPER.

              I SLEEVE NO. 24/40
                                                                         210 mm
GROUND-GLASS
SOCKET. § NO. 12/S
PYREX
                                                                      FOAM ENCASEMENT
                                                                                 180mm   NN   ,     x''^BOILING FLASK-
                                                                                                VjX       2-LITER. ROUND-BOTTOM.  SHORT  NECK,
                                                                                                           WITH I SLEEVE NO. 24/40
                                       Figure 7-1.  Sampling train, flask valve, and flask.
                                                                             B-14

                                                         Ill-Appendix  A-30

-------
S. Rmytnu
  Unless otherwise Indicated, 11  Is Intended that all-
reagents conform to the specifications established by the
Commute* on  Analytical  Reagents of  the American
Chemical Society, where such specifications are avail
•ble; otherwise, use the bet available grade.
  8.1  Sampling   To  prepare ihe  absorbing  solution,
cautiously add 2 8 ml concentrated  HiSO. to I  liter of
deioniied, distilled water. Mil well and  add 6 ml of 3
percent  hydrogen  peroxide,  freshly prepared from  30
percent  hydrogen peroild" solution  The  absorbing
solution should be used within 1 week of lu preparation.
Do not eipose to extreme heat or direct sunlight.
  1.2  Sample Recovery. Two reagents an required (or
simple recovery
  3.2.1  Sodium Hydroxide (IN). Dissolve 40 g NaOH
ID delonlied, distilled water and dilute to 1 liter.
  3.2.2  Water. Delonlied, distilled to conform to ASTM
ipeclOcatlou D1193-74, Type 3. At the  option  of the
analyst, the KMNOi  test for oxldizable organic  matter
may be omitted  when high concentrations of organic
matter are not expected to be present.
  3.3 Analysis. For the analysis, the following reagents
are required'
  3.3.1  Fuming Sulfunc Acid. 15 to 18 percent by weight
tre« sulfur  tnonde.  HANDLE  WITH CAUTION
  332  Phenol White solid.
  333  Sulfunc Acid Concentrated, 95 percent mini
mum assay  HANDLE WITH CAUTION.
  334  Potassium Nitrate  Dried at 105 to 110° C  (220
to Off F) for a minimum of 2 hours Just pnor to prepara-
tion of standard solution.
  335  Standard  KNOi Solution.  Dissolve  exactly
2 IU8 K ol dried potassium nitrate  (KNOj) in deionired,
distilled water and  dilute  to 1  liter with deiorurcd,
distilled water m  a 1,000-ml volurne'.nc flask.
  338  Working  Standard  KNOi Solution  Dilute 10
ml of the standard solution to 100 ml with deionired
distillod water. One mllliliter of the working standard
solution is equivalent to 100 ug nitrogen dioxide  (NOi)
  2 3.7  Water.  Deioruted, distilled as in Section 3 2 '.'
  338  Phenoldisulfonic Acid Solution  Dissolve 25 g
of pure white phenol in  150 ml  concentrated  sulfunc
acid on a steam bath  Cool, add 75 ml fuming  sulfunc
acid, and heat at  100° C (212° F) for 2 hours  Store In
a dark,  stoppered bottle.

4. Procedure*

  4.1 Sampling
  411  Pipette 25 ml  of absorbing solution into a sample
flask, retaining a sufficient quantity for use in preparing
the calibration standards Insert the flask valve  stopper
Into the flask with the valve In the "purge" position
Assemble the  sampling train as shown in Figure 7-1
and place the probe at the  sampling point   Make sure
that all  fittings are  tight and  leak free, and that  all
ground  glass Joints have  been properly greased  with a
high-vacuum,   high-temperature   chlorofliiorocarhon-
based stopcock grease Turn the flask valve and  the
pump valvp to their "evacuate" positions  Evacuate
the flask to 75 mm Hg (3 in. Hg) absolute  pressure, or
less  Evacuation to a pressure approaching the vapor
pressure of water at the exLstlnf: temperature is desirable
Turn the pump valve to its "vent" position and turn
off the pump. Check  for leakage by observing the ma-
nometer lor any  pressure fluctuation  (Any variation
  greater than 10  mm Hg (04 In  Hg) over a per,j,.  of
  1 minute Is not  acceptable, and  the flask  is not to be
•  used until the leakage problem  Is corrected.  Pressure
  in the flask is not to exceed 75 mm Hg (3 in. Hg) absolute
  at the time sampling  is commenced ) Record the volume
  of the flask and valve (Vi). the flajk temperature (T,),
  and the barometric pressure. Turn the  flask valve
  counterclockwise  to  its  "purge" position  and  do the
  same with  the pump valve. Purge the probe and the
  vacuum tube using the squeete bulb. If condensation
 occurs  in the probe and the flask valve area, heat the
 probe  and  purge until  the condensation  disappears
 S'ert, turn the pump valve to its "vent" position. Turn
 the flask valve chxkrwue to its "evactiate" position and
 record the difference in the mercury levels in  the manom-
 eter. The absolute internal pressure In  the flask (P.)
 Is equal to the barometric pressure less the manometer
 reading Immediately turn the flask valve to the "sam-
 ple" position and permit the gas to enter the flask until
 pressures in the flafk and sample line (I e.. duct, stack)
 are  equal. This will usually require about 15 seconds,
 a longer period indicates a "plug" in the probe, which
 must be corrected betore sampling is continued. After
collecting the sample, turn the flafk valve to its "purge"
 position and disconnect  the flafk  from the sampling
train. Shake the ftafk for at least 5 minutes.
  4.1.2  If the gas being sampled contains  Insufficient
oxygen  for the  conversion of NO to NOi  (e g.. an ap-
pLicable subpart of the standard may require taking a
sample  of a calibration gas mixture of NO in Ni), then
oxygen  shall be introduced into the flask to permit this
conversion.  Oxygen may be introduced Into the flask
by one of three  methods;  (I)  Before evacuating  th»
sampling flask, flush  with pure cylinder oiygen. then
evacuate flask to 75 mm Hg  (3 in. Hg) absolute pressure
or less; or (2) Inject oxygen into the flask after samplmf.
or (3) terminate sampling with a minimum of  50 nun
Hg  (2 In Hg)  vacuum remaining in the flask, record
this final pressure, and then vent the flask to  the at-
mosphere until the flask pressure Is almost equal u
atmospheric pressure.
  4.2 Sample Recovery Let the flask set for a minimum
of 18 hours and then shake the contents for 2 minutes
Connect the flask  to a mercury filled U-tube manometer
Open the valve Crom the  flask to the manometei  and
record  the flask  temperature  (TV),  the barometric
pressure, and the difference between the mercury levels
n the manometer  The  absolute internal pressure in
the flask (Pi) is the barometric pressure less the man-
ometer reading. Transfer the contents of the  flask to a
teak-free polyethylene bottle  Rinse the  flask twice
with  5-ml portions of deionized, distilled water and add
the nnse water to the bottle. Adjust the pH to between
8 and 12 by adding sodium hydroxide  (1 N), dropwise
(about 25  to 35 drops)  Check  the pH  by dipping a
atimng rod into the solution and then touching the rod
to the pH test paper Remove as little matejnal as possible
during this step Mark the height of the liquid, level so
that  the container can  be checked lor leakage  after
transport  Label the container  to  clearly identify  its
contents Seal the container for shipplr.j
  4 J   Analysis. Note the level of the liquid tn container
and confirm whether or not any  sample was lost during
shipment;  note this  on the analytical data sheet. If a
noticeable  amount of leakage has occurred, either void
the sample or use methods, subject to the approval of
the Administrator, to correct the final results. Immedi-
ately  prior to analysis,  transfer the contents of the
shipping container to a 50-ml  volumetric flask, and
rinse  the container twice with 5-ml portions of deionired,
distilled water. Add  the nnse water to the  flask and
dilute to the mark with deiomted, distilled water; mix
thoroughly. Pipette  a 25-ml aliquot Into the procelain
evaporating dish.  Return  any  unused  portion of the
sample to  the polyethylene  storage bottle. Evaporate
the 2o-ml aliquot to dryness on a steam  bath  and allow
to cool Add 2 ml phenoldisulfonic acid solution to the
dried residue and tnturate thoroughly with a povleth>l-
ene policeman. Make *ure the solution contacts all the
residue  Add  1 ml deiontied. distilled water and four
drop? of concentrated sul/unc acid. Heat  the solution
on a  steam bath for  3 minutes with occasional stimng
Allow the solution to cool, add 20 ml deionited, distilled
water, mix well by stimng. and add concentrated am-
monium hydroxide,  dropwise.  with constant stimng.
until the pH is 10 (as determined by pH paper). If the
sample contains solids,  these  must be removed  by
 filtration (centrifugation is an  acceptable alternative,
subject to the approval of the Administrator), as follows
 filter through Whatman No 41 filter paper into a 100-ml
 volumetric flask, nnse the evaporating  dish with three
5-ml  portions of deionizeil, distilled »ater, filter these
 three nnses  Wa5h the filter with  at least three  15-m!
 portions of deioniied, distilled water  Add  the filter
 washings to the contents  of the volumetnc flask and
 dilute to the mark  with deionued, distilled water  If
 solids are absent, the solution can tie transferred directly
 to the 100-ml volumetnc flask and  diluted to the mark
 witli deion.ird  distilled  water.  Mix the contents of the
 flask thoroughly,  and measure  the absorbance at  the
optimum  wavelength used for  the standards  (Section
5.2 1), using tlie blank solution as a zero reference. Dilute
 the sample and the blank with equal volumes of deion-
 Ized, distilled  water if the absorhance exceeds At.  the
 absorbance of the 4UO nt N Oi standard (see Section 5.2 2)

4  Col lira/ton

   6 1 Flask Volume  The volume of the collection flu-;.
  flask valve combination  must be known  pnor to sam-
  pling Assemble the  flask and flask valve and  fill »it>
  water, to  the stopcock Measure the volume of water t»
  ±10 ml  Record this volume on the flask.
   6.2  Spectropholoraeter Calibration.
   8.2 1  Optimum Wavelength Determination For botr-
  flied  and  variable  wavelength  spectrophotoraeters
  calibrate  against  standard certified wavelength of 410
  run, every 8 months  Alternatively, for variable wave
  length spectrophotometers. scan the spectrum betweei.
  400 and 416 nm using a 200^ NO: standard solution (see
  Section 522)  If a peak  does not occur, the spectropho-
  tometer is probably malfunctioning, and should be re-
  paired When a peak is obtained  within the 400 to 415 nm
  range, the waveleneth at which this peak occurs shall be
  the  optimum wavelength for the measurement of  ab-
  sorbance for both the standards and samples.
   622  Determination of Spectrophotometer Calihra
  tion  Factor K, Add 0 0. 1 0.  2 0, 3.0. and 4 0 ml of the
  KNOi working standard solution (1 ml-100 rt NOj) to
 a series of five porcelain evaporating dishes. To each, add
 26 ml of absorbing  dilution. 10 ml deionired, distilled
 water, and sodium hydroxide (IN), dropwise, until toe
  6H Is between » and 12 (abouF^S to 35 drops each)
   efinning with the  evaporation step, fo'low  the analy-
 sis procedure of Section 4.3, until the solution has been
 transfejred to the 100 ml  volumetric flask and diluted to
 the mark Measure the absorbance of each solution, at the
optimum wavelength, as determined in Section 621.
This calibration procedure must be repeated on each day
 that samples ar» analyred. Calculate the spectrophotom-
eler calibration factor as follows.
         K,= 100
  S.5  Vacuum Gauge  Calibrate mechanical gauges. If
used,  against a mercury manometer such as that speci-
fied in 2.1.8.
  5.8  Analytical  Balance.  Calibrate  against standard
weights.

A. Calculation*

  Carry ont the calculations, retaining at least one extra
decimal figure beyond that of the acquired data. Round
off figures after final calculations.
  6.1  Nomenclature.
    A — Absorbance of sam pie
    C-Concentration of NO, as NO), dry basis, cor-
       rected  to   standard   conditions,  mg/dscm
       (Ib/dscf)
    /•-Dilution factor  (i e . 23.5,  26/10, etc, required
       only  if sample dilution was needed  to reduce
       the absorbance into the range of calibration).
   K"e — Spectrophotometer calibration factor
    m-Hass of NO, as NOi in gas sample. ia.
   Pi" Final absolute pressure o( fiask. mm Hg (in Hg)
   Pi-Initial absolute  pressure of flask,  mm Hg (m
       Hg).
  Pnd - Standard absolute pressure, 760 mm Hg (29 92 m
       He).
   TV-Final absolute temperature of flask  ,°K CR>
   T.-Initial absolute temperature of flask. "K (°R).
  r.u- Standard absolute temperature, 2.13° K (5S° R)
   V',. -Sample volume  at  standard  conditions (dry
       basis), ml
   V'/- Volume of flask and valve, ral
   V.^Volume of absorbir.tr solution. 25 ml
     2 = 50 'i5, the ai;qui>! factor  (If other  than a  25-ml
       aliquot was ased for anaKsis  tne corresp^nd-
       Ine factor nest he suhsutatod)
  8 2  Sample volume, dry  basis, corrected to standard
conditions


V  —T'« (V,-V  ) [~ — — —
   "~P.«    '    ''IT,    T
                                   Equation 7-1
 where.
  A',-Calibration factor
  AI= Absorbance of the 100-Mg NO? standard
  Aj = Absorbance of the 200-vg NO, standard
  As =» Absorbance of the JdOvig N O; standard
  X4-Absorbance of the 40T>-rf v-ri. «ta—<«*H
  5.3 Barometer. Calibrate against a mercury bann -
eter.
  5.4 Temperature Gauge  Calibrate dial them	   ,
against mercury-in-glass thermometers.
where:
                                   Equation 7-2
                    °K
   A'i — 0.3838 - TT- for metric units
                 mm Hg

                  oo
       = 17.64 r — rr~ f°r English  unit.s
                in. Hg

  6.3  Total Mg NOi per sample.
                                   Equation  7-3

  NOTC.— If other than a 2j-ml aliquot is used for analy-
sis, the factor 2 must be replaced by a corresponding
(actor.
  6.4  Sample concentration,  dry basis, corrected  to
standard conditions.
                    C=Kt
 m
V7.
                                   Equation 7-4
when:
        lW —      for metric units
            /.g/ml


        6.243X 10-* '-^— for English units
7.
  1. Standard Methods or Chemical Analysis. 6th ed.
New  York, D.  Vna Nostrand Co., Inc. 1962. Vol. 1.
p. 329-330.
  2. Standard Method of Test for Oxides of Nitrogen in
Gaseous Combustion Products (Phenoldisulfonic Acid
Procedure). In 1968 Book  of ASTM Standards, Part 2C.
Philadelphia, Pa. 1968. ASTM  Designation D-1608-6O,
p. 725-729.
  ». Jacob, M. B. The Chemical Analysis of Air Pollut-
ants.  New  York.  Interscience Publishers,  Inc.  1960.
Vol. 10. p. 351-356.
  4. Beatty,  R.  L., L. B.  Berger, and H. H. Schrenk.
Determination of Oxides of Nitrogen by the Phenoldisul-
fonic  Acid Method. Bureau of Mines,  U.S. Dept. of
Intenor. R. I. 3687. February 1W3.
  5. Hamil, H.  F.  and D. E. Camann. Collaborative
Study of Method for  the Determination of Nitrogen
Oxide Emissions from  Stationary Sources (Fossil Fuel-
Fired Steam  Generators).  Southwest Research Institute
report for Environmental  Protection Agency. Research
Triangle Park. N.C. October 5, 1973.
  6. Hamil, H.  F.  and R.  E.  Thomas. Collaborative
Study of Method for  the Drtermination of Nitrogen
Oxide Emissions from Stationary  Sources (Nitric Acid
Plants). Southwest  Research  Institute  report for  En-
vironmental  Protection  Agency.   Research Triangle
Park, N.C. May 8,  1974.
                                                                     B-15
                                                            111- Ape end ix  A-
                                        31

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                                    TECHNICAL REPORT DATA
                            (Please read Instructions on the reverse before completing)
1. REPORT NO.
 EPA-340/1-83/015
2.
                              3 RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
   Performance Audit Procedures  for SC>2, NOX,  C02,  and
   62 Continuous Emission Monitoring Systems
                                                            5. REPORT DATE
                                                              January  1983
                              6. PERFORMING ORGANIZATION CODE
 '. AUTHOR(S)

   Entropy  Environmentalists,  Inc.
                              8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
   Entropy  Environmentalists,  Inc.
   P.O.  Box 12291
   Research Triangle Park, NC   27709
                              10 PROGRAM ELEMENT NO.
                              11. CONTRACT/GRANT NO.

                                 68-01-6317
12. SPONSORING AGENCY NAME AND ADDRESS
   OAQPS
   Stationary Source Compliance Division
   Waterside  Mall, 401 M Street,  SW
   Washington,  DC  20460
                              13. TYPE OF REPORT AND PERIOD COVERED
                                 FINAL -  IN-HOUSE
                              14. SPONSORING AGENCY CODE

                                 EPA/200/04
15. SUPPLEMENTARY NOTES
16. ABSTRACT
   This  report presents detailed performance  audit procedures  for  a variety of
   currently available S02  and NOX GEMS.  Specific procedures  for  conducting
   (1) initial monitor inspections/calibration  checks, (2) calibration error tests,
   (3) stratification tests at monitor sampling locations, and (4)  relative accuracy
   tests are included for the  following monitoring systems:  (1)  LSI SM810 S02/NO
   and CM50 02 monitors,  (2) DuPont 460 S02/NOX and Thermox  02 monitors, (3) Contraves
   Goerz GEM 100 S02/N0/C02 monitors, and (4) Environmental  Data Corporation DIGI
   1400  S02/NO/C02 monitors.   These procedures  may be adapted  to other types of
   gas emission monitoring  systems.
 7.
                                KEY WORDS AND DOCUMENT ANALYSIS
                  DESCRIPTORS
                                               b.IDENTIFIERS/OPEN ENDED TERMS
                                            c.  COSATI Field/Group
   Air Pollution

   Monitoring
                  Gas Monitoring  Systems

                  Audit Procedures
18. DISTRIBUTION STATEMENT

   Release  to  Public
                 19. SECURITY CLASS (This Report)
                   unclassified
21. NO. OF PAGES
      76
                                               20. SECURITY CLASS (This page)
                                                 unclassified
                                                                           22. PRICE
EPA Form 2220-1 (Rey. 4-77)   PREVIOUS EDITION is OBSOLETE
                                               B-16

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