United States
Environmental Protection
Agency
Industrial Environmental Research
Laboratory
Research Triangle Park NC 2771 1
EPA-600'2-79-202
November 1979
Research and Development
The Use of pH and Chloride
Electrodes for the
Automatic Control of
Flue Gas Desulfurization
Systems
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into nine series. These nine broad cate-
gories were established to facilitate further development and application of en-
vironmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The nine series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
6. Scientific and Technical Assessment Reports (STAR)
7. Interagency Energy-Environment Research and Development
8. "Special" Reports
9. Miscellaneous Reports
This report has been assigned to the ENVIRONMENTAL PROTECTION TECH-
NOLOGY series. This series describes research performed to develop and dem-
onstrate instrumentation, equipment, and methodology to repair or prevent en-
vironmental degradation from point and non-point sources of pollution. This work
provides the new or improved technology required for the control and treatment
of pollution sources to meet environmental quality standards.
EPA REVIEW NOTICE
This report has been reviewed by the U.S. Environmental Protection Agency, and
approved for publication. Approval does not signify that the contents necessarily
reflect the views and policy of the Agency, nor does mention of trade names or
commercial products constitute endorsement or recommendation for use.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
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EPA-600/2-79-202
November 1979
The Use of pH and Chloride Electrodes
for the Automatic Control of
Flue Gas Desulfurization Systems
by
Clinton Ung, Toby Acciani, and Ray Maddalone
TRW Defense and Space Systems Group
One Space Park
Redondo Beach, California 90278
Contract No. 68-02-2165
Task No. 220
Program Element No. INE624
EPA Project Officer: Frank E. Briden
Industrial Environmental Research Laboratory
Office of Environmental Engineering and Technology
Research Triangle Park, NC 27711
Prepared for
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Research and Development
Washington, DC 20460
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ABSTRACT
The goal of this study was to determine the applicability of chloride and
pH electrodes in automated control systems. Included in this study was a ,
survey of chloride and pH electrode use in different flue gas desulfurization
(FGD) systems and an evaluation test of an industrial pH electrode system.
The survey revealed that chloride ion measurements were only necessary
where high chloride values corresponded with FGD unit corrosion and when
chloride values were used as correction factors in pH calculations. Chloride
ion measurements were not considered necessary for the majority of the surveyed
companies.
The survey found that all surveyed companies use pH measurements to control
scaling and/or to attain optimum performance in FGD units. The most common pH
electrode problem described was residue buildup (scaling) around the electrode,
a condition due to the use of non-self-cleaning (standard type) pH electrodes.
The performances of a self-cleaning and standard-type industrial pH
electrodes were evaluated at the EPA/TVA Shawnee Test FGD facility.
The electrodes were tested during a seven week period with varying dura-
tions of continuous operation. The pH electrode evaluation test uncovered the
following observations. The performances of the self-cleaning and standard-
type electrodes were nearly identical. The benefits of a self-.cleaning pH
electrode can only be realized if electrode scaling is a problem and a long
continuous period (>2 weeks) of pH electrode operation is maintained.
ii
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CONTENTS
Abstract ii
Acknowledgement - iv
1. Introduction 1
2. Conclusions and Recommendations 3
3. Chloride Electrode Survey . 5
Scope of survey 5
Survey results and discussion 5
4. pH Electrode Survey 7
Scope of survey 7
Survey results and discussion 7
5. pH Electrode Test 10
Introduction 10
Criteria for evaluation 10
pH electrode test 11
6. pH Electrode Evaluation 15
Data description and calculations 15
Discussion of results 25
Criteria fulfillment 26
Automation 29
References 30
Appendices
A. Test Plan 31
B. Data for pH Electrode Evaluation 37
iii
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ACKNOWLEDGMENTS
The cooperation among the Tennessee Valley Authority, Bechtel Corporation,
the Environmental Protection Agency, and Electrofact was greatly appreciated.
William Sensing of EPA, Gina Dallabetta, and Dave Rabb of Bechtel, Don Ford
of TVA, Paul Schaff of Electrofact, and Toby Acciani and Ray Maddalone of TRW
were key personnel responsible for the successful completion of this study.
iv
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SECTION 1
INTRODUCTION
This study was performed under the terms of the Environmental Protection
Agency Contract No. 68-02-2165, Task No. 62. "pH and Chloride Sensitive
Electrodes." The effort was directed by William Sensing in the Process
Measurement Branch, Industrial Environmental Research Laboratory of the EPA.
The goal of this study was to determine the applicability of chloride and
and pH electrodes in automated control systems. Included in this study was a
survey of chloride and pH electrode use in different flue gas desulfurization
(FGD) systems and an evaluation test of an industrial pH electrode system.
The study was conducted in the following manner. The survey reviewed
companies utilizing pH and chloride measurements. The methodology and more
important, the utility of the measurements were evaluated. When the utility
of either electrode's measurements was judged necessary for the majority of
the surveyed companies, an evaluation test of the appropriate electrode was
to be planned. The purpose of the evaluation test was to determine the
applicability of the electrode(s) in automated control systems. The criteria
for evaluation were in the areas of maintenance, maintenance schedule,
accuracy, precision, reliability, and durability. Of these criteria main-
tenance was the most critical factor.
f,
The following utilities and sponsoring companies, grouped according to
the type of FGD unit employed, were surveyed for pH and chloride electrode use.
Ash Scrubber
Colstrip - Montana Power Company
Dual Alkali (Sodium/Qalcium) Scrubber
Scholz Electric - Southern Company Services
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Lime Scrubber
Bruce Mansfield - Pennsylvania Power Company
Cane Run - Louisville Gas and Electric (Carbide - Lime)
Green River Power Station - Kentucky Utilities
\
Limestone Scrubber
Lawrence No. 4 - Kansas Power and Light Company
Shawnee Test Facility - EPA/TVA
Sherbourne County - Northern States Power
This report is organized in the following manner. Section 2 lists the
conclusions and recommendations of this study. Section 3 and 4 respectively
describe the results of the chloride and pH measurements survey. Section 5
outlines the pH electrode evaluation test and Section 6 describes the results.
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SECTION 2
CONCLUSIONS AND RECOMMENDATIONS
The results of the chloride measurements survey indicated that:
t The majority of utilities surveyed did not make chloride measurements
The utilities that made chloride measurements used the data to
identify F6D corrosion problems (high chloride values) or to correct
calculations of pH values.
The results of the pH measurements survey indicated that:
All utilities surveyed made pH measurements
The pH data were used to control scaling and to attain optimum
scrubbing performance in an FGD unit.
Evaluation of the pH electrode test data revealed the following facts:
The accuracy and precision of the self-cleaning and standard type
electrode were nearly identical during the duration of the test.
Scaling was a confirmed maintenance problem with the standard-type
electrode.
Clogging of the screen surrounding the electrode was a maintenance
problem with the self-cleaning electrode used in slurry streams.
The overall maintenance of both the self-cleaning and standard type
pH electrode during continuous periods of operation less than two
weeks were equal in slurry streams.
For continouous periods of operation greater than two weeks in
slurry streams, the self^cleaning electrode required slightly less
maintenance.
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The following recommendations are made for the application of chloride
and pH electrodes to automated control systems in F6D units (slurry streams):
Chloride measurements are not necessary unless FGD corrosion
(high chloride values) is a problem or accurate pH calculations
are required.
t For continuous periods of operation less than two weeks the use
of either the standard type or self^cleaning pH electrode is
recommended.
t For continuous periods of operation greater than two weeks, the
self-cleaning electrode is recommended and should require less
maintenance.
If the self-cleaning pH electrode is selected, the required main-
tenance should be significantly reduced when the wire screen sur-
rounding the electrode is removed or the screen mesh size is
increased.
Additional comparisons at different FGD sites.
Longer, uninterrupted periods of comparison.
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SECTION 3
CHLORIDE ELECTRODE SURVEY
SCOPE OF SURVEY
The potential application of chloride measurement equipment to automated
systems was evaluated in this survey. A representative number of power
plants equipped with FGD's were asked whether or not they were making
chloride measurements. The tabulated responses to this question provided
a measure of the industry's interest in chloride measurements. Due to the
low interest in chloride measurements found by the survey, it was decided
not to field test a chloride electrode.
SURVEY RESULTS AND DISCUSSION
The most significant finding was that six out of eight utilities surveyed
did not make chloride measurements. High chloride concentrations (as HC1) may
cause internal FGD unit corrosion. The companies at Cane Run, Colstrip, Green
River, Lawrence, Scholz and Sherbourne reported low chloride values and the
absence of chloride related corrosion problems. At these sites, monitoring
chloride concentration was not necessary for the normal FGD unit operation.
However, monitoring chloride concentrations is necessary at sites where
chloride levels are high and corrosion is a potential problem. The companies
at Bruce Mansfield and Shawnee reported high chloride levels and made routine
chloride measurements as part of the normal FGD unit maintenance schedule.
These measurements were made on grab samples in the laboratory.
At Shawnee, chloride measurements also were used to calculate pH values.
High chloride and magnesium values significantly alter the results of pH
calculations. Thus, if a solid or slurry stream is added to an existing
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stream, the resultant pH value cannot be accurately calculated without
original and resultant chloride and magnesium concentration values. The
equation for calculating the resultant pH values is:
pH = pHR + 1.60 (MgR - Mg + Cl - C1R),
where,
Cl = Expected or new Cl value (g-eq/1) in resultant stream
C1R = Original Cl value (g-eq/1) in stream
Mg = Expected or new Mg value (g-eq/1) in resultant stream
MgR = Original Mg value (g-eq/1) in stream
pH = Expected or new pH in resultant stream
pHR = Original pH in stream
The integration of a chloride electrode into an automated system is only
necessary where high chloride concentration is a problem. The applicability
of the electrode for automation may take two directions. In one method,
chloride measurements are used as a warning device such that operators are
notified of high concentration levels and manual operations are used to
correct the situation. The alternate approach is to completely integrate
chloride measurements into an automated system such that high concentrations
will be automatically corrected by the control devices.
Although the potential exists for chloride electrode application in auto-
mated control systems, the limited interest of surveyed companies in chloride
measurements did not merit a pursuit of a chloride electrode evaluation
test.
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SECTION 4
PH ELECTRODE SURVEY
SCOPE OF SURVEY
The purpose of this survey was to describe the application of pH electrodes
toward the operation of an FGO unit. The surveyed companies were asked about
their use of pH data and problems encountered while obtaining this data. Among
the topics covered were:
a Type of Scrubber
t Type of pH Electrode
Location of pH Electrode
Desired pH or pH Range
Maintenance of pH Electrodes
Problems with pH Electrodes
Use of pH Data
Use of pH Electrode in Automated Control System
SURVEY RESULTS AND DISCUSSION
All of the survey companies use a standard-type, non-self-cleaning pH
electrode. Seven utilities use the Uniloc electrodes. Cane Run and Scholz
use Uniloc plus Leeds and Northrup electrodes. Colstrip uses only Great Lake
electrodes. Sherbourne was employing the Uniloc standard type pH electrode
and testing the Electrofact self-cleaning electrode. Unfortunately detailed
results and their recommendations of the self-cleaning electrode were not
completed or available at the time of this report.
The location of the pH electrodes and the desired pH or pH range varied
considerably among the companies surveyed. The Shawnee Facility makes pH
measurements only at the slurry inlet to the FGD. Lawrence, Scholz, and
Sherbourne located the electrodes at the outlet FGD slurry streanu
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Colstrip makes pH measurements at the recycle pump discharge whereas Bruce
Mansfield measures at the scrubber and absorber discharge. Cane Run and Green
River take measurements at three FGD slurry locations (inlet, middle, and outlet)
Cane Run, Green River, and Shawnee take Inlet measurements and the
respective desired pH (range) values are 8.0-8.5, 8.0-8.5, and 5.5. Cane Run
and Green River "middle" desired values are 6.0-7.0 and 7.5-8.0. Cane Run, Green
River, Lawrence, Scholz, and Sherbourne make outlet measurements and the
desired values are 6.0-7.0, 5.5-7.0, 5.0-7.0, 5.5, and 4.0-6.0. Bruce Mansfield
requires 7.0 and Colstrip 4.5-5.5 at their respective slurry discharge locations.
All electrodes except Electrofact require an acid wash at least once a week.
The Bruce Mansfield and Shawnee sites require acid washings three times a .
week. All the other sites require acid washing once a week or when necessary.
According to site personnel at Cane Run, Lawrence, and Sherbourne, ultrasonic
cleaning shortens the electrode life and was not the preferred method.
The most common problem shared by all three limestone and one lime scrubber
site was residue buildup on the pH electrodes. Cane Run,, Lawrence, and
Shawnee have problems with hard scale forming on the electrodes. Sherbourne
has a coating problem which has been identified not to be gypsum. Colstrip
and Scholz have electrode erosion problems associated with their highly abrasive
(undissolved solids) FGD unit. Bruce Mansfield and Green River did not mention
any problems with the electrodes.
The most common use of pH data was to,control FGD unit scaling at Bruce
Mansfield, Cane Run, Colstrip, Green River, and Shawnee. Bruce Mansfield,
Scholz, and Shawnee used the pH data to optimize performance (scrubbing) in the
FGD unit. Sherbourne used pH data to monitor chemical corrosion and erosion
relative to the additive feed. Lawrence was the only site that did not use pH
data for control or monitoring.
The three lime scrubber sites, Bruce Mansfield, Cane Run, and Green River,
were the only sites that utilized the pH electrodes for an automated system. This
highlights the fact that lime has a much more consistent chemical composition and
dissolves faster than limestone. A system utilizing materials with consistent and
8
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predictable chemical compositions is much easier to automate than a system
with chemically inconsistent materials. Thus, it is expected that automated
lime scrubbing systems would be more prevalent than automated limestone
systems. The Lawrence Facility, a limestone site, has provisions for automa-
tion; however, this system is not utilized.
In summary, the goal of this survey was to assess the use of pH electrodes
and data and to apply these findings toward an effective electrode evaluation
test. Due to the fact that all the survey companies used a non-self-cleaning
electrode, scaling on the electrode was the major maintenance problem.
It was found that accurate pH measurement of slurry streams is very
important for proper operation and prevention of scaling, corrosion, S02 removal and
erosion in an FGD unit. Paramount to successful pH electrode operation is the
prevention of residue buildup and erosion of the electrode, clearly the most
common problems among the utilities. The field evaluation test of a self-
cleaning and standard-type electrode was designed to solve these problems and
to evaluate the applicability of the electrode in an automated system.
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SECTION 5
PH ELECTRODE TEST
INTRODUCTION
The purpose of this pH electrode test is twofold. One aspect of the test
is to determine if the self-cleaning electrode will solve the most common
problem of scaling or residue buildup. The results of this test plus evalua-
tion by other criteria will then be used to determine the applicability of a
self-cleaning electrode in an automated system.
This section describes the nature and procedures of the test. The most
important aspect of this test is a description of the criteria for evaluation.
Specific areas of equipment performance related to applicability in automated
systems are listed in order of importance. The equipment tested, both standard-
type and self-cleaning electrodes, are described. The test location and
equipment placement were chosen and arranged to facilitate maintenance. The
test plan provides a detailed description of the recommended procedures for
the test.
CRITERIA FOR EVALUATION
Before actual testing is initiated, the criteria for evaluating a pH
electrode's applicability in an automated F6D unit must be delineated.
Specific areas of equipment performance which determine successful automated
operation are emphasized. Thus, certain equipment qualities which are minor
considerations in a nonautomated system are major factors in an automated
system and likewise, the reverse may be true. The criteria by which a pH
electrode is to be evaluated are listed in the order of importance:
t Maintenance and maintenance schedule
Reliability and durability
Accuracy and precision
t Transient response
10
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The nearly unanimous opinion of the surveyed companies is that maintenance
is the single most important criteria by which a new electrode is to be
evaluated. The problems of residue buildup and erosion of the electrode
account for the most time and money lost for a pH measurement system. Not
only is "what has to be done" important but also "how often it has to be done"
(maintenance schedule) is critical during an evaluation.
Reliability depends both on the maintenance and durability of the
electrode. Careful evaluation should identify and differentiate a reliability
problem caused by the lack of maintenance or inherent weaknesses. Durability
depends on maintenance and quality of materials and workmanship. Lack of main-
tenance should not be construed as a durability problem.
Carefully made buffer solutions can be used to evaluate accuracy and
precision in the laboratory; however, accurate and precise measurements In
dynamic slurry streams containing percent ranges of total dissolved solids
is very difficult. Judgments that one pH system is correct and another
incorrect are difficult to substantiate when pH differences are small (+0.1 pH).
In addition, the basic principles and materials used for the manufacture of pH
electrodes are fairly common throughout the industry. Any flaw in workmanship or
materials should be a subject for reliability and durability. Thus, accuracy and
precision are extremely important parameters; however, these qualities would
be very difficult to assess under conditions of these test evaluations.
Transient response is another very difficult parameter to evaluate tn a
constantly changing slurry stream. Judgments In this area must Be made with
much discretion with respect to where the electrode was placed, and when the
measurements were made. It was impossible to assess the exact effect of
transient response based on the data uncovered in this program.
PH ELECTRODE TEST
This subsection describes the equipment, test location and test plan.
11
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Equipment Description
The focus of this test is on the electrode, the most critical link in any
pH measurement system. The criteria for equipment performance were selected
to evaluate the electrodes or the primary equipment. Auxiliary or secondary
equipment such as pre-amplifiers (increases signal strength of pH electrode
output), transmitters (modifies pre-amplified signals to be sent over long
distances), meters (provides a visual readout of the pH measured by the elect-
rode), and chart recorders (makes permanent record of pH measurements) are
still important and are evaluated by the same criteria.
In order to avoid confusion the following definitions of terms used in
the remainder of this report are made:
Electrode: Refers to the piece of equipment placed in the
liquid stream. Thus, pH measurements are not
possible with only one electrode
Chart Recorder: Refers to equipment recording the pH
measurements on chart paper.
Chart Recorder Readings: Refers to the pH measurements (in chart units or
adjusted to pH units) recorded on the chart
paper.
Meter: Refers to equipment that provides
visual readouts of instantaneous pH measurements.
Meter Readings: Refers to the pH measurements recorded by a
technician reading the meter.
In this evaluation, both a self-cleaning and a standard-type (non-self-
cleaning) pH electrodes were tested. Except during equipment failures, meter
and chart recorder readings were made for both self-cleaning and standard-type
electrodes.
A pH electrode manufactured by Electrofact was speci-
fied as the self-cleaning electrode to be tested and evaluated. This electrode
was selected because it was designed to reduce maintenance and lengthen
maintenance schedule intervals as compared to the standardrtype electrode.
12
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The Electrofact 135 6/Z electrode 1s composed of the electrode assembly,
preamplifier, and transmitter which contains the pH meter and output for a
strip chart recorder. Special features of the electrode assembly are automatic
temperature compensation and the self-cleaning electrode mechanism. Once
every seven seconds, the electrode is wiped by a moving viton diaphragm or.
nylon brush. This constant wiping motion is designed to prevent the buildup
of any deposits in the electrode. The range of the meter is from 4.5 to 6.5
pH units which corresponds to a 4-20 ma output. With a 28.7 n + 0.01% resistor
connected in parallel, the chart recorder output ranged from 114.8 to 574.0 mV.
Meter and chart recorder readings were taken from a standard-type pH
electrode placed in the same slurry stream. A Uniloc pH electrode connected
to an EMC meter and control room chart recorder was the arrangement used
by the utility at the test site. In addition to meter and chart recorder readings,
laboratory pH measurements were made for the slurry stream. A separate slurry line
is fed into the control room when a grab sample is taken. A standard laboratory pH
meter capable of being read to ^0.01 pH unit was utilized for these measurements.
Test Location
The test site was the Shawnee Test facility operated by the Tennessee
Valley Authority under the direction of Bechtel Corporation and the Environ-
mental Protection Agency. The self-cleaning electrode was placed in an external
slurry pot fed by a rubber hose from the venturi slurry stream. (Originally
the test was to be conducted at a turbulent contact absorber (TCA); however, the
unit was down at the time of this test). A baffle deflected the incoming slurry
stream to prevent breakage of the glass electrodes by solid materials. The
Uniloc (referred as "standard") electrode was placed in a similar apparatus
fed by the same slurry line. The "standard" pH electrode measurements were
recorded by a chart recorder and displayed on a meter.
13
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Test Plan
Under normal operating conditions at the Shawnee facility, laboratory measure-
ments and meter readings are used to monitor the slurry stream. Thus, this
evaluation will base its results on laboratory and meter readings from both
self-cleaning and standard pH electrodes. When meter readings are absent, chart
recorder readings are adjusted to correspond to meter readings. This adjustment
is accomplished by determining the average arithmetic differences between
corresponding meter and chart recorder readings and adding/subtracting this
difference to/from the chart recorder readings.
The complete test plan is contained in Appendix A. A brief summary of the
test plan is given below:
Every two hours the following pH measurements were made:
- Laboratory pH readings
- Meter and chart recorder readings for both self^cleaning
and standard pH electrodes
Both self^-cleaning and standard pH electrode systems were
recalibrated under the following conditions:
- Differences between the self-cleaning and standard pH
electrode meter readings were greater than 0.2 pH unit
- Differences between the self-cleaning pH electrode meter
readings and the laboratory measurements were greater than
0.5 pH unit (a common range used by the Shawnee facility)
t All laboratory pH measurements of the slurry stream were
made within 15 minutes after the sample was taken.
14
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SECTION 6
PH ELECTRODE EVALUATION
DATA DESCRIPTION AND CALCULATIONS
The raw data recorded during the field test Included:
Self-cleaning pH electrode meter and chart recorder readings
Standard-type pH electrode meter and chart recorder readings
t Laboratory measurements by conventionaV pH jpete*.
This data is presented in Table B (Appendix). All meter readings and
laboratory measurements were recorded directly in pH units. All chart recorder
* *
readings were initially recorded in chart paper units and were later converted
to pH units.
The equation used to convert the self-cleaning pH electrode chart
recorder readings into pH units is:
pH = (X)(0.21777) + 4.00 where
X = Chart paper units
The equations used to convert the standard pH electrode chart recorder
readings into pH units are:
pH = (X)(0.06) + 4.00 for 4-10 pH paper
= (X)(0.10) + 2.00 for 2-10 pH paper where
X = Chart paper units
All pH data were rounded off to the nearest 0.01 pH unit.
Because the standard procedures at Shawnee utilized the meter readings
15
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and laboratory measurements of pH to monitor the F6D unit, comparisons
involving the self-cleaning and standard-type pH electrode were based on the
meter readings. When meter readings were not available, the chart recorder
readings were adjusted to correspond to the meter readings. This adjustment is
made by computing arithmetic averages of the numbers appearing in the ApH
column for each type of electrode. The ApH figures represent the differences
between the meter and chart recorder readings. A negative ApH value represents
a higher meter reading. Performance comparisons among the self-cleaning pH
electrode, standard-type pH electrode and laboratory measurements were listed
in the following columns in Table B:
a The column labeled "ApH ± (#2 - #1)" represents the differences
between the standard and self-cleaning meter readings. In the
absence of meter readings, the arithmetic ApH (chart-meter) averages
are added/subtracted from the chart readings. For example: The
standard meter readings average a higher reading (0.04 pH) than the
chart readings. On 3-24 at 500 the standard meter reading is
extrapolated to be 6.32 (6.28 - (-0.04)). Note: -0.04 is negative
because of the way the calculations for ApH were arranged. The ApH
(#2 - #1) is equal to 0.02 (6.32-6.30). A negative number for the
column ApH (#2 - #1) represents a higher self-cleaning meter reading.
the column labeled "ApH ± (#3 - #1)" represents the difference
between the lab measurements and the self-cleaning meter readings.
A negative number indicates a higher meter reading.
The column labeled "ApH ± (#3 - #2)" represents the difference between
the lab measurements and the standard meter readings. A negative
number indicates a higher meter reading.
Table 1 summarizes the data representing differences between the chart and
meter readings of the self-cleaning pH electrode. In this table only the
absolute values of the pH data are averaged. This calculation reveals the
magnitude of the reading differences. The real values are averaged in Table 6.
This real value average will indicate a positive or negative value bias of
the data. The calculated values in Table 1 are listed in two columns. One
column is a running average or cumulative average of the absolute value
differences. The second column is the absolute value averages for each group.
16
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A group represents a continuous, uninterrupted set of data. At the start of
each group the instruments are recalibrated. This set of absolute value
"group" averages can indicate a proper calibration or malfunction of the
instrument. In addition, Table 1 lists the down time, both cumulative and
group, between continuous readings.
Tables 2 through 5 present data in a similar style as Table 1.
Table 6 summarizes Tables 1 through 5 and includes the real value averages
of theApH values. Table 7 lists the significant events during the test.
In summary, the tables are:
Table 1. Self Cleaning pH Electrode: Chart Readings vs Meter Readings.
Table 2. Standard pH Electrode: Chart Readings vs Meter Readings.
Table 3. Self Cleaning vs Standard pH Electrode Meter Readings.
Table 4. Self Cleaning pH Electrode Meter Readings vs Laboratory
Measurements.
Table 5. Standard pH Electrode Meter Readings vs Laboratory Measure-
ments.
Table 6. Summary of Tables 1 through 5.
Table 7. Chronological Listing of Events During pH Electrode Test.
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TABLET. SELF-CLEANING pH ELECTRODE: CHART READINGS vs. METER READINGS
00
ApH-Absolute Value
Time of Readings Number of Testing Average
Hour (Date) Hours Hours Down Time
Cumulative Per Group
From To Cumulative Per Group (Std Dev) (Std Dev) Cumulative Per Group Comment
1300(3-13)
1500(3-14)
1100(3-15)
2300(3-16)
0500(3-21)
1300(3-22)
0900(3-28)
1500(3-28)
0100(3-30)
1700(3-30)
1900(4-1)
1500(4-3)
1300(4-12)
1500(4-16)
2100(4-18)
0900(4-19)
1600(4-20)
1500(3-14) 26
1100(3-15)
2300(3-16)
0500(3-21) 128
1300(3-22)
0900(3-28) 268
1500(3-28)
0100(3-30) 302
1700(3-30)
1900(4-1) 350
1500(4-3)
1300(4-12) 564
1500(4-16)
2100(4-18)
0900(4-19)
1600(4-20)
0900(5-3)
Overall Total
26 0.10(0.13) 0.10(0.13)
20 20 A
56 36 B
102 0.05(0.08) 0.03(0.05)
88 32 B
140 0.04(0.06) 0.04(0.02)
94 6 B
34 0.04(0.05) 0.04(0.01)
110 16 B
48 0.04(0.05) 0.04(0.04) .
154 44 B
214 0.04(0.04) 0.03(0.02)
252 98 C
306 54 B
318 12 D
349 31 C
654 305 E
0.04(0.04)
A - Cage surrounding pH electrode plugged
B - Scrubber unit down
C - Meter and chart recorder inoperable
D - Meter readings only - Chart recorder inoperable
E - Meter readings only not calibrated
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TABLE 2. STANDARD pH ELECTRODE: CHART READINGS vs. METER READINGS
VO
ApH- Absolute Value
Time of Readings Number of Testing Average
Hour (Date) Hours Hours Down Time
Cumulative Per Group
From To Cumulative Per Group (Std Dev) (Std Dev) Cumulative Per Group Comment
1300(3-13) 1100(3-15) 46 46 0.06(0.02) 0.06(0.02)
1100(3-15) 2300(3-16) 36
2300(3-16) 0500(3-21) 148 102 0.04(0.02) 0.03(0.02)
0500(3-21) 1300(3-22) 68
1300(3-22) 0300(3-24) 186 38 0.04(0.03) 0.05(0.05)
0300(3-24) 1500(3-27) 152
1500(3-27) 0900(3-28) 204 18 0.04(0.03) 0.03(0.01)
0900(3-28) 1500(3-28) 158
1500(3-28) 0100(3-30) 238 34 0.04(0.03) 0.03(0.01)
0100(3-30) 1700(3-30) 174
1700(3-30) 1900(4-1) 286 48 0.04(0.03) 0.04(0.04)
1900(4-1) 1500(4-3) 218
1500(4-3) 1500(4-16) 598 312 0.05(0.040 0.05(0.05)
1500(4-16) 2100(4-18) 272
2100(4-18) 1300(4-22) 686 88 0.05(0.04) 0.04(0.03)
1300(4-22)
1100(4-25)
2300(4-29)
1100(4-25)
2300(4-29)
2300(5-3)
360
0.22(0.24) 469
0.24(0.17) 565
36 A
32 A
84 B
6 A
16 A
44 A
54 A
88 B
109 C
96 D
A - Scrubber Unit down
B - Chart readings only - Meter inoperable
C - Meter and chart recorder not working properly
D - Replaced chart recorder
-------
TABLE 3. SELF-CLEANING vs. STANDARD pH ELECTRODE METER READINGS*
Time of Readings
Hour (Date)
From
To
Number of Testing
Hours
Cumulative Per Group
apH-Absolute Value
Average
Cumulative
(Std Dev)
Per Group
(Std Dev)
Hours Down Time
Cumulative Per Group Comment
ro
o
1300(3-13)
1500(3-14)
1100(3-15)
2300(3-16)
0500(3-21)
1300(3-22)
0900(3-28)
1500(3-28)
0100(3-30)
1700(3-30)
1900(4-1)
1500(4-3)
1300(4-12)
1500(4-16)
2100(4-18)
0900(4-19)
1600(4-20)
1500(3-14)
1100(3-15)
2300(3-16)
0500(3-21)
1300(3-22)
0900(3-28)
1500(3-28)
0100(3-30)
1700(3-30)
1900(4-1)
1500(4-3)
1300(4-12)
1500(4-16)
2100(4-18)
0900(4-19)
1600(4-20)
0900(5-3)
26 26 0.11(0.11) 0.11(0.11)
128 102 0.06(0.07) 0.04(0.03)
268 140 0.07(0.06) 0.07(0.05)
302 34 0.07(0.06) 0.10(0.04)
350 48 0.07(0.06) 0.07(0.04)
564 214 0.10(0.08) 0.16(0.10)
576 12 0.10(0.09) 0.19(0.12)
0.36(0.30)
20
56
88
94
110
154
252
306
337
642
20
36
32
16
44
98
54
31
305
A
6
C
B
C
D,E
In cases when there were no meter readings, the ApH arithmetic average (difference between the meter vs. chart readings)
was added/subtracted from the chart readings.
A - Cage surrounding self-cleaning pH electrode plugged
6 - Scrubber unit down
C - Self-cleaning pH electrode meter and chart recorder inoperable
D - Self-cleaning pH electrode meter could not be calibrated. Chart recorder inoperable
E - Standard pH electrode meter and chart recorder not operating properly.
-------
TABLE 4. SELf-CLEANIN pH ELECTRODE METER READINGS vs. LABORATORY MEASUREMENTS*
ApH-Absolute Value
Tine of Readings Nwnber of Testing Average
Hour (Date) Hours Hours Bean Time
Cumulative Per Group
From To Cumulative Per Group (Std Dev) (Std Dev) Cumulative Per Group Cemnent
1300(3-13)
1500(3-14)
1100(3-15)
2300(3-16)
0500(3-21)
1300(3-22)
0900(3-28)
1500(3-28)
0100(3-30)
1700(3-30)
1900(4-1)
1500(4-3)
1300(4-12)
1500(4-16)
2100(4-18)
0900(4-19)
1600(4-20)
1500(3-14) 26 26 0.35(0.12) 0.35(0.12)
1100(3-15) 20 20 A
2300(3-16) 56 36 B
0500(3-21) 128 102 0.24(0.10) 0.21(0,08)
1300(3-22) 88 32 B
0900(3-28) 268 140 0.26(0.13) 0.28(0.15)
1500(3-28) 94 6
0100(3-30) 302 34 0.27(0.13) 0.33(0.07)
1700(3-30) 110 16 B
1900(4-1) 350 48 0.27(0.12) 0.27(0.08)
1500(4-3) 154 44 B
1300(4-12) 564 214 0.29(0.15) 0.33(0.19)
1500(4-16) 252 98 C
2100(4-18) 306 54 B
0900(4-19) 576 12 (0.31)(0.18) 0.92(0.19)
1600(4-20) 337 31 ' C
0900(5-3) 0.30(0.17) 642 305 D +0.29 (0.18)
*
In cases when there were no meter readings, the ApH arithmetic average (difference between the meter vs. chart readings)
was added/subtracted from the chart readings.
A - Cage surrounding self-cleaning pH electrode plugged
B - Scrubber unit down
C - Self-cleaning pH electrode meter and chart recorder inoperable
D - Self-cleaning pH electrode meter could not be calibrated. Chart recorder inoperable.
-------
TABLE 5. STANDARD pH ELECTRODE METER READINGS vs. LABORATORY MEASUREMENTS*
ApH-Absolute Value
Time of Readings Number of Testing Average
Hour (Date) Hours Hours Down Time
Cumulative Per Group
From To Cumulative Per Group (Std Dev) (Std Dev) Cumilative Per Group Comment
1300(3-13) 1100(3-15) 46 46 0.30(0.11) 0.30(0.11)
1100(3-15) 2300(3-16) 36 36 A
2300(3-16) 0500(3-21) 148 102 0.23(0.10) 0.20(0.08)
0500(3-21) 1300(3-22) 68 32 A
1300(3-22) 0900(3-28) 288 140 0.25(0.14) 0.26(0.17)
0900(3-28) 1500(3-28) 74 6 A
1500(3-28) 0100(3-30) 322 34 0.24(0.13) 0.23(0.07)
0100(3-30) 1700(3-30) 90 16 A
1700(3-30) 1900(4-1) 370 48 0.25(0.13) 0.26(0.09)
1900(4-1) 1500(4-3) 134 44 A
1500(4-3) 2300(4-13) 618 248 0.31(0.13) 0.41(0.13)
2300(4-13) 0100(4-15) 160 26 B
0100(4-15) 1500(4-16) 656 38 0.32(0.16) 0.56(0.08)
1500(4-16) 2100(4-18) 214 54 A
2100(4-18) 1100(4-25) 832 176 0.32(0.19) 0.27(0.30)
1100(4-25) 2300(5-3) 0.30(0.21) 418 204 C
*In cases when there was no meter readings, the ApH arithmetic average (difference between the meter vs. chart readings)
was added/subtracted from the chart readings.
A - Scrubber unit down.
B - Laboratory measurements were not made.
C - Standard pH electrode meter and chart recorder not working properly.
-------
TABLE 6. SUMMARY OF TABLES 1 THROUGH 5
Total ApH-Absolute
Number Value ApH-Arithmetic
of Hours Average Average
Item Tested (Std Dev.) (Std Dev.)
TABLE 1.
Self-Cleaning Electrode: Meter 564 0.04 (p.04) +0.03 (0.05)
vs. Chart
TABLE 2.
Standard Electrode: Meter 686 0.05 (0.04) -0.04 (0.05)1
vs. Chart
TABLE 3.
Self-Cleaning vs. Standard 576 0.10 (0.09) 0.00 (0.13T
TABLE 4. .
Self-Cleaning vs. Laboratory 576 0.31 (048) -0.30 (0.19T
Measurements
TABLE 5. .
Standard vs. Laboratory 832 0,32 (0.19) -0.30 (0.22)°
Measurements
*A positive number indicates the chart recorder indicated a higher pH
value and vice versa.
2Self-cleaning pH electrode meter tended to have higher values during the
first half of the test and the standard meter had higher values during
the second half.
3Lab measurements tended to have lower readings than the on-line meters.
23
-------
TABLE 7. CHRONOLOGICAL LISTING OF EVENTS
DURING pH ELECTRODE TEST
Time Period
Hour (Date)
From
To
Effective Down Time
(Hours)
pH Electrodes
Scrubber S.C./Std
Remarks
1300 (3-13) End of test
1500 (3-14) 1100 (3-15)
1100 (3-15) 2300 (3-16) 36
0500 (3-21) 1300 (3-22) 32
0300 (3-24) 1500 (3-27)
0300 (3-28) 0900 (3-28)
0900 (3-28) 1500 (3-28) 6
0100 (3-30) 1700 (3-30) 16
1900 (4-1) 1500 (4-3) 44
1300 (4-12) 1500 (4-16)
1500 (4-16) 2100 (4-18) 54
2300 (4-18) End of test
0900 (4-19) 1600 (4-20)
2300 (4-19) 0700 (4-20)
1500 (4-22) End of test
20/
/84
/ 6
98/
31/
Initiation of test
Self-cleaning electrode
screen clogged
Scrubber unit down
Scrubber unit down
Standard pH electrode
meter failed
Standard pH electrode
meter failed
Scrubber unit down
Scrubber unit down
Scrubber unit down
Self-cleaning pH electrode
meter could not be
calibrated
Scrubber unit down
Self-cleaning pH electrode
operating without
calibration
Self-cleaning pH electrode
meter chart recorder
inoperable
Standard pH electrode
meter failed
Standard pH electrode
meter not operating
properly
Total Down Times
188
149/98
24
-------
DISCUSSION OF RESULTS
Before a discussion of results is undertaken, it must be noted that cumu-
lative calculations involving pH values represent selected periods of time.
The reasons for these time period restrictions are as follows. The cumulative
calculations in Table 1, 3, and 4 were stopped after 4-20-79 because the self-
cleaning pH electrode meter controls were inoperative and calibration was not
possible. The calculations in Table 2 and 5 were stopped after 4-25-79
because the following groups pH average values demonstrated a 550% change.
Agreement between the meter and chart readings was very good for both
self cleaning and standard pH electrodes. The self-cleaning pH meter tested
to show (0.03 pH) lower readings than the chart recorder. The standard pH
meter tended to show (0.04 pH) higher readings than the chart recorder.
Over a period of 576 hours, the real average ApH value between the
meter reading of self-cleaning and standard pH electrodes demonstrated
0.00 pH unit agreement, even though the magnitude of the absolute value
averages was 0.10 pH unit. It is interesting to note that the self-cleaning
pH electrode meter tended to show higher values during the first half of the
test and the standard pH electrode pH meter tended to show higher values
during the second half of the test. These results should be evaluated in
view of the fact that the pH electrode meter accuracy is typically +0.02 pH
unit.
\
Both self-cleaning and standard pH meters tended to show a 0.30 pH unit
higher reading than the laboratory measurements. The self-cleaning electrode
demonstrated a 0.32 pH absolute value ApH difference from the laboratory
measurements whereas the standard electrode demonstrated a slightly lower,
0.31 pH unit, variation.
The most obvious problem that Table 7 reveals is the down time exper-
ienced by the F6D unit. Almost 190 hours during the testing period were not
used for evaluating the electrodes.
25
-------
CRITERIA FULFILLMENT
In review, the criteria of electrode evaluation include the following
areas of performance:
Maintenance and Maintenance Schedule
Reliability and Durability
t Accuracy and Precision
Transient Response
Maintenance and Maintenance Schedule
The evaluation of the maintenance and maintenance schedule of a pH
electrode involves both objective data and subjective opinions. Although
difficult, this report will differentiate these two potentially conflicting
observations.
The most common maintenance complaint about the standard (non-self-
cleaning) electrode is the effort for cleaning. For example, an initially
clean electrode is placed in a slurry stream. Within a few hours, a thin
coating develops around the electrode. Between three to seven days after
immersion, a hard scale develops around the electrode and impairs pH perform-
ance. The design of the self-cleaning electrode is to wipe the electrode
(every seven seconds) before a crust can develop.
The initial impression about the self-cleaning electrode was that it
required the same amount of maintenance as the standard electrode. However,
the required maintenance was quite different. A wire screen cage surround-
ing the self cleaning electrode was susceptible to plugging. This problem
can be eliminated by the use of a larger mesh screen. The recalibration of
this electrode required as much or more effort than the standard electrode.
This opinion could be due to the operator's unfamiliarity with the equipment.
Although the overall comments about maintenance indicated little dif-
ference between the two electrodes, these comments reflect the number of
recalibrations during the test. The frequency of pH electrode calibration
averaged to more than once per week during the testing period. This unusually
26
-------
high number is caused by the frequency of down time of the FGD unit, a
problem beyond the control of this test. The test plan required that the
pH electrodes be recalibrated if an interruption of service was experienced.
During the test, the FGD unit was inoperative several times. As a result,
an impression of significant maintenance may have been caused by the problems
with the FGD unit.
During the longer periods of continuous operation (214 and 140 hours),
the self-cleaning electrode required less electrode maintenance than the
standard electrode. The wire screen had to be frequently checked for
clogging and as a result, this effort was nearly equal to the effort of
cleaning the standard electrodes.
The number of problems associated with the FGD unit made evaluation of
the maintenance schedule very difficult. However, it can be extrapolated
that during longer periods of continuous operation (200* hours) and if the
wire screen was removed, the self-cleaning electrode would have a longer
period of time between maintenance.
Reliability and Durability
During the duration of the test, no reliability or durability problems
occurred with either the self-cleaning or standard-type pH electrode. However
both self-cleaning and standard-type pH electrode meters developed electrical
problems. During the middle of the test, the EMC meter (connected to the
standard electrode) was inoperable. The meter was repaired and placed back
into service. Toward the end of the test, the Electrofact meter (connected to
the self-cleaning electrode) developed problems with the calibration controls.
These controls affect the slope and asymmetry of the calibration curve.
This problem was probably caused by the combination of fragile controls and
the unfamiliarity of the operators with the meter. In summary, the meters
for both pH electrodes caused reliability problems in the measurement
systems.
Accuracy and Precision
The precision between both pH measurement systems (self-cleaning and
standard-type) appear to be good. Although the overall pH difference
(arithmetic average) was 0.00 pH unit, the standard deviation was 0.13 pH
unit, an indication of the variation between the two systems. This large
27
-------
standard deviation supports observations that the self-cleaning pH electrode
measurement system tended to have higher readings during the first half of
the test and lower readings during the last half of the test.
The accuracy of the pH measurement systems is a very difficult parameter
to assess. The constant dynamics of a slurry stream in combination with
different reference positions of the electrodes and laboratory measurements
complicate the assessment. Nevertheless, comparisons among both electrode
systems and the laboratory results reveal certain trends. As mentioned
before, the agreement between the two pH meter systems is good, the overall
average difference being 0.00 pH unit with a standard deviation of 0.13 pH
unit. However, when the data of either self-cleaning or standard pH elec-
trode were compared to the laboratory measurements, both comparisons revealed
nearly identical results. The laboratory measurements had an overall 0.30
pH unit lower reading than either of the on-line pH meters. This obvious
systematic error indicates problems with the location of the measurement
systems or equipment problem.
This discrepancy between the on-line meter readings and the laboratory
measurements indicates a systematic error in operating procedures or equipment
performance. The most obvious error is the difference of operating procedures.
The on-line pH meters measure the instantaneous pH of the slurry stream.
Because of the undissolved solids, flue gases, turbulence, and rapid flow
rates, the slurry steam is in a state of non equilibrium at the time of an on-
line pH measurement. On the other hand, when a grab sample for laboratory
measurement is taken, the slurry aliquot may undergo equilibrium changes
before the pH test. Depending on the original conditions (temperature,
pressure, stoichiometry, etc.) of the slurry stream, supersaturated solutions
will precipitate and non saturated solutions will dissolve solids and gases
immediately after the aliquot is taken. Thus the difference in taking a pH
measurement (on-line vs. laboratory) may account for the discrepancies in
the results.
28
-------
Transient Response
Transient response Is the ability of an instrument to handle change
of the measurement parameters. The constant dynamics and unpredictable
nature of a slurry stream does not allow an accurate assessment of transient
response. Thus no conclusions or observations could be made about this
parameter during the test.
AUTOMATION
The goal of this evaluation test was to determine the applicability
of the self-cleaning electrode in automated FGD control systems. This appli-
cability was determined in the study by equipment performance in the areas
of
Maintenance and maintenance schedule
Reliability and durability
Accuracy and Precision
Transient response
and comparing these findings with the results of a standard-type pH electrode.
It was found that the performance of the self-cleaning pH electrode system
was nearly Identical to the standard-type pH electrode system. The relia-
bility problems were similar and the maintenance requirements, although
different, were also similar in effort expended. The frequency of FGD unit
problems created an unexpected variable in the test. This variable, because
of the frequency of meter recalibration, made the maintenance requirements
higher than normal for both pH measuring systems. These requirements could
conceal any significant maintenance differences between the two systems, and
make a false impression of frequent maintenance.
Under certain conditions, the self-cleaning electrode might have reduced
maintenance requirements and would then be more applicable in automated FGD
control systems. These conditions would include a larger mesh size or complete
removal of the screen surrounding the electrode assembly. With this modifica-
tion, and during periods of long continuous operation (>2 weeks), the self-
cleaning electrode would require less maintenance.
29
-------
REFERENCES
1. Rowland, C., "Correction of Liquor pH for Dissolved Mg and Cl
Concentrations," Bechtel Corporation Inter-Office memorandum,
February 10, 1976.
30
-------
APPENDIX A
TEST PLAN
31
-------
TEST PLAN FOR TIE TASK # 62
I. INTRODUCTION
The purpose of this task is to test an industrial pH electrode used to
monitor limestone slurry streams. Equipment manufactured by Electrofact was
selected to be used in the Unit 110 TCA at the Shawnee Power Plant facility.
II. INSTALLATION AND EQUIPMENT SETUP
The installation of the Electrofact pH equipment is to be arranged and
performed by the TVA personnel at the Shawnee Power Plant. The basic pH
equipment and electrical connections will be supplied by EPA. Any additional
mounting equipment will be supplied by the TVA facility.
The Electrofact pH electrode will be placed in an external slurry pot fed
by auxiliary slurry lines. Laboratory measurements are made by standard pH
measurements of grab samples from a slurry line fed directly into the
laboratory.
The pH equipment to be tested is composed of the pH electrode, mechanical
electrode wiper assembly, sender unit, pH meter, transmitter, and strip chart
recorder. The range of the pH meter is from 4.5 to 6.5. The
recorder. The range of the pH meter is from 4.5 to 6.5. The output of the
transmitter is 4 milliamperes at pH 4.5 and 20 milliamperes at pH 6.5. A 23.7
ohm resistor is placed across the current source in order to create a voltage
source for the strip chart recorder. Table 1 summarizes the corresponding pH
readings, the output current and voltages of the transmitter, and predicted
strip chart recorder readings. These data are important for calibration of
this equipment.
32
-------
The pH electrode and meter are factory adjusted and calibrated. However,
the strip chart recorder does not give readings in pH units and must be
calibrated. A column in Table A-l gives approximate strip chart recorder
deflections in chart paper divisions for various ph readings. The following
procedure must be used to calibrate the strip chart recorder.
STRIP CHART RECORDER pH CALIBRATION PROCEDURE
1. For normal operation, set the chart paper speed to 2.5 cm/hr.
For calibration, set the chart paper speed to 2.5 cm/min.
2. Place the pH electrodes in a pH 5.0 buffer.
3. Go to the strip chart recorder and mark on the chart paper
the pH of the buffer and when (time and date) the electrodes
were placed in the buffer.
4. Repeat Steps #2 and #3 with a pH 6.0 buffer.
5. Reset the chart paper speed to 2.5 cm/hr.
III. TEST PROCEDURE
The following procedures are to be used for proper evaluation of the
pH electrode.
1. Make sure the strip chart recorder was calibrated by the
procedures outlined in Section II. Set the chart paper speed to
2.5 cm/hr.
2. Use the "FIELD FORM FOR pH MEASUREMENT TEST" to record all data.
3. Every two hours or when the normal slurry pH measurement is made
by the technician, enter the date and time onto the form.
4. Enter in the column, "Laboratory pH Meter Readings," the pH of
the slurry as determined by the technician.
5. Enter in the column, " Electrofact pH Meter Reading," the reading
of the Electrofact pH meter at the time of the laboratory
measurement.
6. Enter in the column, "Strip Chart Recorder Reading," the number
of chart divisions that the recorder pen is deflected. Maximum
deflection is 10 units. Give reading to nearest 0.1 chart units.
33
-------
7. Initial the last column.
8. Continue Steps #2 through #7 for one month or approximately
30 days.
9. If the differences between the laboratory measurements and the
Electrofact pH meter is greater than 0.2 pH units,
a. Pull the Electrofact electrodes from the system.
b. Thoroughly clean the electrodes.
c. Recalibrate the strip chart recorder, Section II.
If these steps are performed and the difference is still greater
than 0.2 pH units, try to troubleshoot the system. If the trouble-
shooting is unsuccessful, resume the test, write down appropriate
comments, and contact Clinton Ung, (213) 536-2448.
10. If equiment failure and/or breakage occurs,
a. Replace the damaged equipment.
b. Recalibrate the strip chart recorder, Section II.
c. Resume test.
If the equipment cannot be repaired immediately, notify
Clinton Ung, (213) 536-2448.
11. At the end of the test, (i.e., after approximately 30 days)
thoroughly clean the Electrofact electrodes and recalibrate the
strip chart recorder according to Section II. This is very
important because correlation beween the Electrofact pH meter
readings and the transmitter milliampere output values must be made.
34
-------
Table A-l
Chart Paper
£H
4.5 pH
4.6
4.7
4.8
4.9
5.0
5.1
5.2
5.3
5.4
5.5
5.6
5.7
5.8
5.9
6.0
6.1
6.2
6.3
6.4
6.5
ma Output
4.0
4.8
5.6
6.4
7.2
8.0
8.8
9.6
10.4
11.2
12.0
12.8
13.6
14.4
15.2
16.0
16.8
17.6
18.4
19.2
20.0
mV w/28.7n
114.8
137.8
160.7
183.7
206.6
229.6
252.6
275.5
298.5
321.4
344.4
367.4
390.3
413.3
436.2
459.2
482.2
505.1
528.1
551.0
574.0
u 1 1 1 J IUI1 Ull 1 UO
(0-600 fflV Sjoan)
2.3
2,8
3.2
3.7
4.1
4.6
5.1
5.5
6.0
6.4
6.9
7.3
7.8
8.3
8.7
9.7
9.6
10.1
10.6
11.0
11.5
35
-------
1 FIELD FORM FOR pH MEASUREMENT TEST I
1 Recorder Calibration: pH Buffer-* Chart paper divisions 1
1 pH ___ Buffer = _____ Chart paper divisions 1
Date
1
1
1
I
1
1
1
1
I
I
1
I
1
L.
Time
Laboratory
pH Meter Reading
(pH Units)
Electrofact
pH Meter Reading
(pH Units)
Strip Chart Performed!
Recorder Reading) by 1
Chart Divisions (Initials)!
n
1
1
]
d
J
36
-------
APPENDIX B
DATA FOR pH ELECTRODE EVALUATION
37
-------
TABLE B. DATA FROM pH ELECTRODE EVALUATION TEST (pH UNITS)
Self -Cleaning
Date Time Meter #1
3-13 100
300
500
700
900
1100
1300
1500
1700
1900
2100
2300
3-14 100
300
500
700
900
5.95
5.44
5.33
5.60
5.50
5.37
5.30
5.33
5.35
5.60
5.25
Chart #1
5.99
5.82
5.71
5.66
5.55
5.44
5.33
5.34
5.38
5.33
5.28
ApH ±
0.04+
0.38+
0.38+
0.06+
0.05+
0.07+
0.03+
0.01+
0.03+
0.27-
0.03+
- -- - i
Standard
Meter #2
5.57
5.31
5.44
5.43
5.32
5.29
5.25
5.30
5.36
5.33
5.26
Chart #2
5.50
5.26
5.41
5.39
5.37
5.26
5.20
5.20
5.28
5,28
5.20
ApH ±
0.07-
0.05-
0.03-
0.04-
0.05+
0.03-
0.05-
0.10-
0.08-
0.05-
0.06-
^^^^^^mmmmmmmmmmmmmmmmmmim***^^**
Lab
leasurements
#3
5.65
5.80
5.70
5.35
5.07
5.00
4.95
4.95
4.98
4.90
5.01
^ ^ . .mi..- linn , ^» »^^^^ ^
ApH ± ApH ± ApH ±
(#2-#l) (#3-#l) (#3-#2)
0.38-
0.13-
0.11+
0.17-
0.18-
0.08-
0.05-
0.03-
0.01+
0.27-
0.01+
-
0.30-
0.36+
0.37+
0.25-
0.43-
0.37-
0.35-
0.38-
0.37-
0.70-
0.24-
0.08+
0.49+
0.26+
0.08-
0.25-
0.29-
0.30-
0.35-
0.38-
0.43-
0.25-
In cases with no meter readings, the ApH arithmetic average (difference between meter vs. chart readings)
was added/subtracted from the chart readings.
-------
TABLE B. DATA FROM pH ELECTRODE EVALUATION TEST (pH UNITS) (Continued)
CO
VO
Self-Cleaning
Date
3-14
cont
3-15
Time Meter #1
1100
1300
1500
1700
1900
2100
2300
100
300
.500
700
900
1100
1300
1500
1700
1900
5.25
5.20
5.15
5.90
6.20
6.40
6.32
6.27
6.18
6.10
6.10
6.10
5.20
Chart #1
5.28
5.23
5.20
5.79
6.21
6.43
6.37
6.31
6.22
6.12
6.11
6.11
5.20
ApH ±
0.03+
0.03+
0.05+
0.11-
0.01+
0.03+
0.05+
0.04+
0.04+
0.02+
0.01+
0.01+
Standard
Meter 12
5,27
5.14
5.05
5.16
5.20
5.20
5,25
5.27
5.30
5.33
5.32
5.32
5.25
MWIHfl^MWHVIMIBB^HIH^^W
1
1 . ,
Chart #2 ApH ±
5,21
5.08
5.02
5.08
5.14
5.16
5.20
5.21
5.26
5.28
5.26
5.26
5.17
0.06-
0.06-
0.03-
0.08-
0.06-
0.04-
0.05-
0.06-
0.04-
0.05-
0.06-
0.06-
0.08-
Lab
Measurements ApH ± ApH ± ApH ±
#3 (12-11) (13-11) (13-12)
5.04
5.00
4.84
4.79
4.94
4.95
4.87
4.84
4.94
5.00
4.85
4.96
5.04
-
0.02+
0.06-
0.10-
0.74
1.00-
1.20-
1.07-
1.00-
0.88-
0.77-
0.78-
0.78-
0.05+
0.21-
0.20-
0.31-
1.11-
1.26-
1.45-
1.45-
1.43-
1.24-
1.10-
1.25-
1.14-
0.16-
0.23-
0.14-
0.21-
0.37-
0.26-
0.25-
0.38-
0.43-
0.36-
0.33-
0.47-
0.36-
0.21-
In cases with no meter readings, the ApH arithmetic average (difference between meter vs. chart readings)
was added/subtracted from the chart readings.
-------
TABLE B. DATA FROM pH ELECTRODE EVALUATION TEST (pH UNITS) (Continued)
Date
3-15
cont
3-16
3-17
'""""' ' .^-.ii.iiiui. p [^^^^^^^^M
Self-Cleaning
Time Meter #1 Chart #1 ApH ±
2100
2300
100
300
500
700
900
1100
1300
1500
1700
1900
2100
2300 5.40 5.44 0.04+
100 5.85 5.89 0.04+
300 5.90 5.95 0.05+
500 5.95 5.97 0.02+
Standard Lab
U_. _..»«_A«4-r- Anil 0. AnU 4- AnU +
Meter 12 Chart #2 ApH ± #3 (#2-#l) («-*!) (#3-12)
^M « .MIHM MM ! « .^ B^ ^ ^ ^^
,
(
5.44 5.37 0.07- 5.21 0.04+ 0.19- 0.23-
5.85 5.80 0.05- 5.66 0.0 0.19- 0.19-
5.89 5.87 0.02- 5.54 0.01- 0.36- 0.35-
5.91 5.88 0.03- 5.56 0.04- 0.39- 0.35-
*In cases with no meter readings, the ApH arithmetic average (difference between meter vs. chart readings)
was added/subtracted from the chart readings.
-------
TABLE B. DATA FROM pH ELECTRODE EVALUATION TEST (pH UNITS) (Continued)
- uiiimu .11. ii «i
Sel
Date Time Meter #1
3-17 700
cont 900
1100
1300
1500
1700
1900
2100
2300
3-18 -100
300
500
700
900
1100
1300
1500
1700
6.00
5.90
5.90
5.55
5.90
5.91
5.95
5.95
5.95
5.93
5.95
5.95
5.95
5.95
5.90
5.90
5.90
5.95
IIMWMrilllllHIMIWIVIIIIIBMllflWn^WWIIMBANIMVIla^
f-Cleaning
Chart #1 ApH ±
6.05
5.96
5.94
5.81
5,93
5.94
5.94
5.96
5.96
5.95
5.97
5.96
5.96
5.96
5.94
5.94
5.93
5.96
0.05+
0.06+
0.04+
0,26+
0.03+
0.03+
0.01+
0.01+
0.01+
0.02+
.0.02+
0.01+
0.01+
0.01+
0.04+
0.04+
0.03+
0.01+
-. . i M n»n- ii
Standard
Meter #2
5,99
5.91
5.91
5.80
5.86
5.95
5,95
5.97
5.99
. 5.99
6.00
5.99
5.97
5.96
5.97
5.90
5.88
5.85
Chart #2 ApH ±
5.98
5.86
5.88
5,80
5.86
5.93
5.93
5.97
5.96
5.97
5.99
5.96
5.94
5.91
5.86
5.83
5.84
0.01-
0.05-
0.03-
0
0
0,02-
0.02-
0
0.03-
0.02-
0.01-
0.03-
0.03-
0.06-
0.04-
0.05-
0.01-
Lab
Measurements ApH ± ApH ± ApH ±
#3 -(12-11) (13-11) (13-12)
5.80
5.77
5.79
5.43
5.70
5.72
5.74
5.73
5.86
5.75
5.75
5.73
5.84
5.77
5.72
5.71
5.70
5.72
0.01-
0.01+
0.01+
0.25+
0.04-
0.04+
0
0.02+
0.04+
0.06+
0.05+
0.04+
0.02+
0.01+
0.07+
0
0.02-
0.10-
0.20-
0.13-
0.11-
0.12-
0.20-
0.19-
0.21-
0.22-
0.09-
0'. 18-
0.20-
0.22-
0.11-
0.18-
0.18-
0.19-
0.20-
0.23-
0.19-
0.14-
0.12-
0.37-
0.16-
0.23-
0.21-
, 0.24-
0.13-
0.24-
0.25-
0.26-
0.13-
0.19-
0.25-
0.19-
0.18-
0.13-
"in cases with no meter readings, the ApH arithmetic average (difference between meter vs. chart readings)
was added/subtracted from the chart readings,
-------
TABLE B. DATA FROM pH ELECTRODE EVALUATION TEST (pH UNITS) (Continued)
Self-Cleaning
Date Time Meter #1
3-18 1900
cont 21QO
2300
3-19 100
300
500
700
900
1100
1300
1500
1700
1900
2100
2300
3-20 100
300
500
5.95
5.90
5.90
5.85
5.87
5.90
5.85
5.90
5.89
6.03
5.95
5.96
5.75
5.95
5.95
5.97
5.93
5.95
Chart #1
5.96
5.93
5.92
S.88
5.91
5.89
5.88
5.93
5.91
6.00
5.98
5.98
6.00
5.99
5.96
5.96
5.95
5.97
ApH ±
0.01+
0.03+
0.02+
0.03+
0.04+
0.01-
0.03+
0.03+
0.02+
0.03-
.0.03+
0.02+
0.25+
0.04+
0.01+
0.01-
0.02+
0.02+
^W^»~«M«W««^^^^M^«W~«M~~B«M «
Standard
Meter #2
5.90
5.89
5.88
5.84
5.85
5.85
5.89
5.90
5.86
5.92
5.97
5.94
5.96
5.90
5.88
5.92
5.89
5.91
iV*^vMMMMMMiaiHMi^B^^B«
u
' » PI
Chart #2 ApH ±
5.86
5.86
5.85
5.80
5.82
5.81
5.86
5.86
5.81
5.93
5.94
5.90
5.92
5.85
5.85
5.87
5.86
5.86
0.04-
6.03-
0.03-
0.04-
0.03-
0.04-
0.03-
0.04-
0.05-
0.01+
0.03-
0.04-
0.04-
0.05-
0.03-
0.05-
0.03-
0.05-
Lab
leasurements ApH ± ApH ± ApH ±
#3 (#2-#l) (#3-11) (#3-#2)
5.74
5.70
5.72
5.52
5.68
5.58
5.63
5.69
5.66
5.84
5.79
5.76
5.77
5.75
5.74
5.78'
5.60
5.61
0.05-
0.01-
0.02-
0.01-
0.02-
0.05-
0.04+
0
0.03-
0.11-
0.02+
0.02-
0.21+
0.05-
0.07-
0.05-
0.04-
0.04-
0.21-
0.20-
0.18-
0.33-
0.19-
0.32-
0.22-
0.21-
0.23-
0.19-
0.16-
0.20-
0.02+
0.20-
0.21-
0.19-
0.33-
0.34-
0.16-
0.19-
0.16-
0.32-
0.17-
0.27-
0.26-
0.21-
0.20
0.08-
0.18-
.0.18-
0.19-
0.15-
0.14-
0.14-
0.29-
0.30-
In cases with no meter readings, the ApH arithmetic average (difference between meter vs. chart readings)
was added/subtracted from the chart readings.
-------
TABLE B. DATA FROM pH ELECTRODE EVALUATION TEST (pH UNITS) (Continued)
CO
""" - " '- - ' - -T T--T 1 --- ..- -
Self-Cleaning
Date
3-20
cont
3-21
Time Meter #1
700
900
1100
1300
1500
1700
1900
2100
2300
.100
300
500
700
900
1100
1300
1500
5.95
5.95
5.95
5.90
5.82
5.85
5.90
5.95
5.90
5.95
5.96
5.95
Chart #1
5.97
5.96
5.96
5.93
5.88
5.86
5.93
5.93
5.93
5.95
5.99
5.97
ApH ±
0,02+
0.01+
0.01+
0.03+
0.06+
0.01+
0.03+
0.02-
0.03+
0
0.03+
0.02+
in mn mil ,^^^. a i Mi
Standard
Meter #2
5.90
5.88
5.85
5.82
5.83
5.80
5.84
5.85
5.88
5.88
5.92
5.89
MV^B^^^V^VOMWimp^^^Hflll
1
1 r
Chart #2 ApH ±
5,87
5,84
5.80
5.80
5.80
5.80
5.80
5.80
5.84
5.86
5.89
5.86
0.03-
0.04-
0.05-
0,02-
0.03-
0
0.04-
0.05-
0.04-
0.02-
0.03-
0.03-
Lab
Measurements ApH ± ApH ± ApH ±
#3 (12-11) (13-11) (13-12)
5.85
5.82
5.73
5.69
5.50
5.55
5.61
5.65
5.12
5.66
5.85
5.81
0.05-
0.08-
0.10-
0.08-
0.01+
0.05-
0.06-
0.10-
0.02-
0.07-
0.04-
0.06-
\
0.10-
0.13-
0.22-
0.21-
0.32-
0.30-
0.29-
0.30-
0.28-
0.29-
0.11-
0.14-
0.05-
0.06-
0.12-
0.13-
0.33-
0.25-
0.23-
0.20-
0.26-
0.22-
0.07-
0.08-
In cases with no meter readings, the ApH arithmetic average (difference between meter vs. chart readings)
was added/subtracted from the chart readings.
-------
TABLE B. DATA FROM pH ELECTRODE EVALUATION TEST (pH UNITS) (Continued)
Date
3-21
cont
3-22
Self -Cleaning
Time Meter #1 Chart #1 ApH ±
1700
1900
2100
2300
100
300
500
700
'900
1100
1300 5.95 5.81 0.14-
1500 6.07 6.11 0.04+
1700 6.13 6.18 0.05+
1900 6.30 6.22 0.08-
2100 6.25 6.29 0.04+
2300 6.30 6.33 0.03+
Standard Lab
Measurements
Meter 12 Chart #2 ApH ± #3
'
6.26 6.01 0.25- 6.07
6.25 6.23 0.02- 5.75
6.29 6.28 0.01- 5.80
6.32 6.25 0.07- 6.01
6.38 6.34 0.04- 5.08
6.42 6.39 0.03- 6.28
.. 1 1. 1 « .mi 11 1 .
ApH ± ApH ± ApH ±
(12-11) (13-11) (13-12)
0.31+ 0.12+ 0.19-
0.18+ 0.32- 0.50-
0.16+ 0.33- 0.49-
0.02+ 0.27- 0.31-
0.13+ 1.17- 1.30-
0.12+ 0.02- 0.14-
''in cases with no meter readings, the ApH arithmetic average (difference between meter vs. chart readings)
was added/subtracted from the chart readings.
-------
TABLE B. DATA FROM pH ELECTRODE EVALUATION TEST (pH UNITS) (Continued)
' ' ' '"" " - ....-..- " 1 . ..... !..!. < !
Self -Cleaning
Date Time Meter #1
3-23 100
300
500
700
900
1100
1300
1500
1700
1900
2100
2300
3-24 100
300
500
700
900
1100
6.30
6.30
6.30
6.35
6.33
6.35
6.35
6.40
6.30
6.32
6.31
6.30
6.30
6.35
6.30
6.35
6.35
6.38
Chart #1
6.33
6.32
6.34
6.36
6.36
6.40
6.41
6.37
6.36
6.37
6.36
6.36
6.36
6.37
6.37
6.38
6.40
6.40
ApH ±
0.03+
0.02+
0.04+
0.01+
0.03+
0.05+
0.06+
0.03-
0.06+
0.05+
0.05+
0.05+
0.06+
0.02+
0.07+
0.03+
0.05+
0.02+
Standard
Meter 12
6.42
6.44
6.47
6,45
6.45
6.44
6.38
6.23
6.32
6.36
6,41
6.38
6.36
6.36
*
*
*
*
MMIKMIIIBIMMIHHMBIMIMI
1
Chart #2 ApH ±
6.40
6.42
6.46
6.43
6.40
6.40
6.34
6.35
6.28
6.33
6.39
6.34
6.34
6.31
6.28
6.28
6.31
6.32
0.02-
0.02-
0.01-
0.02-
0.05-
0.04-
0.04-
0.12+
0.04-
0.03-
0.02-
0,04-
0.02-
0.05-
Lab
Measurements ApH ± ApH ± ApH ±
#3 (12-11) (13-11) (13-12)
6.10
6.08
6.12
5.95
6,00
5.98
6.07
6.20
6.02
6.03
6.09
6.15
6.13
6.16
6.09
6.01
6.11
6.10
0.12+
0.14+
0.17+
0.10+
0.12+
0.09+
0.03+
0.17-
0.02+
0.04+
0.10+
0.08+
0.06+
0.01+
0.02+
0.03-
0.06-
0.02-
0.20-
0.22-
0.18-
0.40-
0.33-
0.37-
0.28-
0.20-
0.28-
0.29-
0.22-
0.15-
0.17-
0.19-
0.21-
0.34-
0.24-
0.28-
0.32-
0.36+
0.25-
0.50-
0.45-
0.46-
0.31-
0.03-
0.30-
0.33-
0.32+
0.23-
0.23-
0.20-
0.23-
0.31-
0.24-
0.26-
*In cases with no meter readings, the ApH arithmetic average (difference between meter vs. chart readings)
was added/subtracted from the chart readings.
-------
TABLE B. DATA FROM pH ELECTRODE EVALUATION TEST (pH UNITS) (Continued)
Self-Cleaning
Date Time Meter #1
3-24
cont 1300
1500
1700
1900
2100
2300
3-25 100
300
500
700
900
1100
1300
1500
1700
1900
2100
2300
6.40
6.44
6.45
6.35
6.35
6.30
6.32
6.30
6.30
6.40
6.40
6.40
6.40
6.40
6.36
6.33
6.34
6.35
Chart 11
6.43
6.44
6.46
6.48
6.35
6.34
6.35
6.37
6.36
6.36
6.42
6.43
6.43
6.45
6.43
6.38
6.38
6.38
ApH ±
0.03+
0
0.01+
0.13+
0
0.04+
0.03+
0.07+
0.06+
0.04-
0.02+
0.03+
0.03+
0.05+
0.07+
0.05+
0.04+
0.03+
f~WWMB^^~M»v«««MBII>MW«_«B.
Standard
Meter #2 Chart #2 ApH
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
.32
.35
.37
.24
.24
.22
.22
.23
.22
.26
.28
.29
.28
.28
.27
.24
.22
.21
^^^^^^^W^HHHWHHtM
Lz
Measut
± i
6,
6.
6.
6.
6.
6.
6.
6,
6.
6.
6.
6.
6.
..! 1 .. ..... 1 !- . 1 1 II ' -"' ' '""
ib
"ements ApH ± ApH ± ApH ±
f3 (12-11) (13-11) (13-12)
17
17
15
05
12
22
12
07
07
15
13
06
05
6.07
6.15
6.09
6.10
6.13
0.04-
0.05-
0.04-
0.07-
0.07-
0.04-
0.06-
0.03-
0.04-
0.10-
0.08-
0.07-
0.08-
0.08-
0.05-
0.05-
0.08-
0.10-
0.23-
0.27-
0.30-
0.30-
0.23-
0.08-
0.20-
0.23-
0.23-
6.25-
0.27-
0.34-
0.35-
0.33-
0.21-
0.24-
0.24-
0.22-
0.19-
0.22-
0.26-
0.23-
0.16-
0.04-
0.14-
0.20-
0.19-
0.15-
0.19-
0.27-
0.27-
0.25-
0.16-
0.19-
0.16-
0.12-
In cases with no meter readings, the ApH arithmetic average (difference between meter vs. chart readings)
was added/subtracted from the chart readings.
-------
TABLE B. DATA FROM pH ELECTRODE EVALUATION TEST (pH UNITS) (Continued)
--in ". ., , . , - 1 t L_I mj_l_- -I -_"_..ji-;i m l !_._-. ;-
Self-Cleaning
Date Time Meter #1
3-26 100
300
500
700
900
1100
1300
1500
1700
1900
2100
2300
3-27 100
300
500
700
900
1100
6.30
6.35
6.30
6.35
6.30
6.33
6.36
6.35
6.34
6.40
6.40
6.32
6.32
6.30
6.30
6.29
6.33
6.35
Chart #1
6.36
6.36
6.34
6.36
6.32
6.36
6.40
6.38
6.38
6.36
6.40
6.37
6.35
6.34
6.34
6.33
6.36
6.36
ApH ±
0.06+
0.01+
0,04+
0.01+
0.02+
0.03+
0.04+
0.03+
0.04+
0.04-
0
0.05+
0.03+
0.04+
0.04+
0.04+
0.03+
0.01+
HMttflMVMWHMi^V^MIItM«*IHaH*liatM«HM»IIWHVI*I^W^H
Standard
Meter #2 Chart #2 ApH ±
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
.22
.22
.22
.22
.26
.25
.27
.27
.24
.28
.30
.29
.28
.28
.23
,23
.22
.22
Lab
Measurements ApH ± ApH ± ApH ±
#3 (#2-11) (13-11) (13-12)
6
6
6
6
5
6
6
6
6
6
6
6
6
6
6
5
6
6
.11
.15
.08
.00
.93
.12
.02
.12
.07
.02
.04
.15
.08
.04
,04
.98
.03
.02
0.04-
0.09-
0.04-
0.09-
0.00
0.04-
0.05-
0.04-
0.06-
0.08-
0.06-
0
0.00
0.02+
0.03-
0.02-
0.07-
0.09-
0.19-
0.20-
0.22-
0.35-
0.37-
0.21-
0.34-
0.23-
0.27-
0.38-
6.36-
0.17-
0.24-
0.26-
0.26-
0.31-
0.30-
0.33-
0.15-
0.11-
0-18-
0.26-
0.37-
0.17-
0.29-
0.19-
0.21-
0.30-
0.30-
0.18-
0.24-
0.28-
0.23-
0.29-
0.23-
0.24-
In cases with no meter readings, the ApH arithmetic average (difference between meter vs. chart readings)
was added/subtracted from the chart readings.
-------
TABLE B. DATA FROM pH ELECTRODE EVALUATION TEST (pH UNITS) (Continued)
00
Self-Cleaning
Date
3-27
cont
3-28
Time Meter #1
1300
1500
1700
1900
2100
2300
100
300
500
700
900
1100
1300
1500
1700
1900
2100
2300
6.30
6.30
6.30
6.29
6.32
6.30
6.30
6.30
6.30
6.33
6,30
6.39
6.35
6.40
6.40
6.55
Chart #1 ApH ±
6.34
6.35
6.34
6.33
6.34
6.32
6.34
6.34
6.33
6.36
6.36
6.42
6.40
6.43
6.45
6.49
0.04+
0.05+
0.04+
0.04+
0.02+
0.02+
0.04+
0.04+
0.03+
0.03+
0.06+
0.03+
0.05+
0.03+
0.05+
0.06+
Standard
Meter 12
*
6.25
6.23
6.22
6.23
6.20
6.22
6.23
*
*
6.21
6.28
6.26
6.28
6.30
6.34
V^M^^HM4MOi«hM^4«a*BMMai
u
" r
Chart #2 ApH ±
6.22
6.24
6.22
6.18
6.19
6.16
6.19
6.19
6.18
6.18
6.17
6.24
6.23
6.25
6.27
6.31
0.01-
0.01-
0.04-
0.04-
0.04-
0.03-
0.04-
0.04-
0.04-
0.03-
0.03-
0.03-
0.03-
Lab
leasurements ApH ± ApH ± ApH ±
#3 (12-11) (13-11) (13-12)
5.91
5.98
5.90
6.02
6.06
6,05
6.09
6.11
6.04
5.42
6.02
6.07
6.09
5.99
6.04
6.10
0.04-
0.05-
0.07-
0.07-
0.09-
0.10-
0.08-
0.07-
0.08-
0.11-
0.09-
STOP
0.11-
0.09-
0.12-
0.10-
0.21-
0.39-
0.32-
0.40-
0.27-
0.16-
0.25-
0.21-
0.19-
0.26-
0.91-
0.28-
STOP
0.32-
0.26-
0.41-
0.36-
0.45-
0.35-
0.27-
0.33-
0.20-
0.17-
0.15-
0.13-
0.12-
0.18-
0.80-
0.19-
STOP
0.21-
0.17-
0.29-
0.26-
0.24-
In cases with no meter readings, the ApH arithmetic average (difference between meter vs. chart readings)
was added/subtracted from the chart readings.
-------
TABLE B. DATA FROM pH ELECTRODE EVALUATION TEST (pH UNITS) (Continued)
10
'" " ' - ' ,-....!..!. .. ,., , .11 , I,.,.,,,,,.,,,...,.,,., mi,
Self-Cleaning
Date Time Meter #1
3-29 100
300
500
700
900
1100
1300
1500
1700
1900
2100
2300
3-30 100
300
500
700
900
1100
6.45
6.45
6.45
6.45
6.50
6.45
6.38
6.42
6.40
6.41
6.39
6.37
6.40
Chart #1
6.48
6.47
6.48
6.49
6.52
6.49
6.46
6.46
6.45
6.45
6.44
6.41
6.44
ApH ±
0.03+
0.02+
0.03+
0.04+
0.02+
0.04+
0.08+
0.04+
0.05+
0.04+
0.05+
0.04+
0.04+
__H_VVVH,.w,^.HHWaB^Hnnw_WHHHWVM
Standard
Meter 12
6.34
6.33
6.34
6.36
6.38
6.35
6.36
6.36
6.34
6.33
6.30
6.29
6.31
^^H^MIH^HMHaHIIIIHHI^B
h
Chart #2 ApH ±
6.30
6.30
6.32
6.33
6.34
6.31
6.34
6.36
6.33
6.30
6.28
6.29
6.28
0,04-
0.03-
0.02-
0.03-
0.04-
0.04-
0.02-
0
0.01-
0.03-
0.02-
0
0.03-
Lab
leasurements
#3
6.11
6.15
6.14
6.18
6.19
6.21
6.20
6.04
6.08
6.13
6.10
5.91
5.98
ApH ± ApH ± ApH ±
(12-11) (#3-#l) (#3-#2)
0.11-
0.12-
0.11-
0.09-
0.12-
0.10-
0.02-
0.06-
0.06-
0.08-
0.09-
0.08-
0.09-
0.34-
0.30-
0.31-
0.27-
0.31-
0.24-
0.18-
0.38-
0.32-
0.28-
6.29-
0.46-
0.42-
0.23-
0.18-
0,20-
0.18-
0.19-
0.14-
0.16-
0.32-
0.26-
0.20-
0.20-
0.38-
0.33-
*In cases with no meter readings, the ApH arithmetic average (difference between meter vs. chart readings)
was added/subtracted from the chart readings.
-------
TABLE B. DATA FROM pH ELECTRODE EVALUATION TEST (pH UNITS) (Continued)
en
o
[[jii
Sel
Date Time Meter #1
3-30
cont 1300.
1500
1700
1900
2100
2300
3-31 100
300"
'500
'700
900
1100
1300
1500
1700
1900
2100
2300
6.45
6.30
6.35
6.33
6.28
6.22
6.13
6.05
5.90
5.57
5.60
5.55
5.55
5.53
5.57
5.65
f-C1eaning
Chart #1 ApH ±
6.28
6.33
6.36
6.35
6.29
6.25
6.15
6.06
5.84
5.59
5.63
5.58
5.57
5.55
5.60
5.67
0,17-
0,03+
0.01+
0.02+
0.01+
0.03+
0.02+
0.01+
0.06-
0.02+
0.03+
0.03+
0.02+
0.02+
0.03+
0.02+
m^V^_W»MV«l^ ^^^^***i«M>B_>^_
Standard
Meter #2
6.29
6,22
6.25
6.25
6.20
6.19
6.11
5.97
5.81
5.64
5.68
5.65
5.61
5.66
5.58
5.62
^^^^^"""P
1
r
Chart #2 ApH ±
6.18
6.20
6.23
6.23
6.18
6.16
6.08
5.96
5.78
5.67
5.64
5.63
5.57
5.61
5.57
5.62
0,17-
0.02-
0,02-
0.02-
0.02-
0.03-
0.03-
0,01-
0.03-
0.03+
0.04-
0.02-
0.04-
0.05-
0.01-
0
Lab
teasurements ApH ± ApH ± ApH ±
#3 (#2-#l) (13-11) (13-12)
,
6.07
6.01
6.13
6.07
6.00
5.89
5.79
5.65
5.47
5.25
5.29
5.39
5.39
5.26
5.37
5.33
0.16-
0.08-
0.10-
0.08-
0.08-
0.03-
0.02-
0.08-
0.09-
0.07+
0.08+
0.10+
0.06+
0.13+
0.01+
0.03-
0.38-
0.29-
0.22-
0.26-
0.28-
0.33-
0.34-
6.40-
0.43-
0.27-
0.31-
0.16-
0.16-
0.27-
0.20-
0.32-
0.22-
0.21-
0.12-
0.18-
. 0.20-
0.30-
0.32-
0.32-
0.34-
0.34-
0.39-
0.26-
0.22-
0.40-
0.21-
0.29-
*In cases with no meter readings, the ApH arithmetic average (difference between meter vs. chart readings)
was added/subtracted from the chart readings.
-------
TABLE B. DATA FROM pH ELECTRODE EVALUATION TEST (pH UNITS) (Continued)
^^MMi^fe
Sel
Date Time Meter #1
4-1 100
300
500
700
900
1100
1300
1500
1700
1900
2100
2300
4-:2 100
300
500
700
900
1100
5.65
5.78
5.75
5.66
5.65
5.70
5.90
5.91
5.84
6.00
^WBWBMAfl^BIHBfeBMMMMV^HMtMaaAIH^^^^aMlaMf^V^M
f -Cleaning
Chart #1
5.79
5.77
5.76
5.69
5.75
5.75
5.87
5.92
5.95
6.00
ApH ±
0,14+
0.01-
0.01+
0.03+
0.10+
0.05+
0.03-
0.01+
0.11+
0
M>Mi^_BM«BWW«_VaiMaHa«BMM«M«l>WW
-------
TABLE B. DATA FROM pH ELECTRODE EVALUATION TEST (pH UNITS) (Continued)
tn
rs>
Date
4-2
cont
4-3
**^^^**BHI*IHB"II>BHI'MMII<'IIIH'*VHIV**I'BIBH*I*II'|I^^
Self -Cleaning
Time Meter #1 Chart #1 ApH ±
1300
1500
1700
1900
2100
2300
100
300
500
.700
900
1100
1300
1500 5.82 5.81 0.01-
1700 5.90 5.91 0.01+
1900 5.95 5.99 0.04+
2100 6.05 6.05 0
2300 6.00 6.06 0.06+
!»MH(^H*VVMMHIIiMIIMWHIIIIMia>MIHIiaiBMIfeiH»«llw1MIHia^^HIIBIIHVIMa^^ ~ ~ ~
Standard Lab
U^n «...**«».«*. 4* *» ArtU O. Anil 4- A nU 4-
Meter 12 Chart #2 ApH ± #3 (#2-#l) (#3-#l) (#3-#2)
-
*
^
6.01 5.92 0.09- 5.88 0.19+ 0.06+ 0.13-
6.03 5.98 0.05- 5.79 0.13+ 0.11- 0.24-
6.14 6.09 0.05- 5.77 0.19+ 0.18- 0.37-
6.18 6.11 0.07- 5.85 0.13+ 0.25- 0.38-
6.11 6.07 0.04- 5.78 0.11+ 0.22- 0.33-
*In cases with no meter readings, the ApH arithmetic average (difference between meter vs. chart readings)
was added/subtracted from the chart readings.
-------
TABLE B. DATA FROM pH ELECTRODE EVALUATION TEST (pH UNITS) (Continued)
to
- ' - "' "1 !. .. ..!.. . . , .HIM... .1. -.1 .,,. Ill
Self-Cleaning
Date Time Meter #1
4-4 100
300
500
700
900
1100
1300
1500
1700
1900
2100
2300
4-5 100
300
500
700
900
1100
6.10
6.10
6.06
6.05
6.10
6.06
6.05
6.13
6.10
6.10
6.15
6.15
6.15
6.15
6.17
6.20
6.15
6.15
Chart #1
6.05
6.11
6.08
6.08
6.09
6.09
6.09
6.15
6.13
6.16
6.19
6.17
6.19
6.18
6.21
6.19
6.15
6.17
ApH ±
0.05-
0.01+
0.02+
0.03+
0.01-
0.03+
0.04+
0.02+
0.03+
0.06+
0.04+
0.02+
0.04+
0.03+
0.04+
0.01-
0
0.02+
^^^IMIIH^^
Standard
Meter #2
6.19
6.20
6.17
6.15
6.17
6.19
6.18
6.25
6.21
6.25
6.26
6.28
6.29
6.29
6.32
6.30
, 6.25
6.25
Chart f;
6.10
6.10
6.11
6.11
6.16
6.15
6.06
6.20
6.19
6.22
6.23
6.24
6.27
6.25
6.28
6.26
6.22
6.20
ii"
2 ApH ±
0.09-
0,10-
0.06-
0.04-
0.01-
0.04-
0.12-
0.05-
0.02-
0.03-
0.03-
0.04-
0.02-
0.04-
0.04-
0.04-
0.03-
0.05-
T
Lab
Measurements ApH ± ApH ± ApH ±
#3 (12-11) (#3-#l) (#3-#2)
5.71
5.89
5.89
5.87
5.87
5.91
5.87
6.15
5.94
5.91
5.92
5.89
5.98
5.79
5.85
6.00
5.93
5.92
0.09+
0.10+
0.11+
0.10+
0.07+
0.13+
0.13+
0.12+
0.11+
0.15+
0.11+
0.13+
0.14+
0.14+
0.15+
0.10+
0.10+
0.10+
0.39-
0.21-
0.17-
0.18-
0.23-
0.15-
0.18-
0.02+
0.16-
0.19-
0.23-
0.26-
0.17-
0.36-
0.32-
0.20-
0.22-
0.23-
0.48-
0.31-
0.28-
0.28-
0.30-
0.28-
0.31-
. 0.10-
0.27-
0.34-
0.34-
0.39-
0.31-
0.50-
0.47-
0.30-
0.32-
0.33-
*In cases with no meter readings, the ApH arithmetic average (difference between meter vs. chart readings)
was added/subtracted from the chart readings.
-------
TABLE B. DATA FROM pH ELECTRODE EVALUATION TEST (pH UNITS) (Continued)
(ft
Self -Cleaning
Date Time
4-5
cont 1300
1500
1700
1900
2100
2300
4-6 100
300
500
'700
900
1100
1300
1500
1700
1900
2100
2300
Meter #1
6.10
6.10
6.00
6.00
6.05
6.02
5.96
6.00
5.90
5.69
5.35
5.20
5.35
4.95
5.35
5.55
5.80
5.70
Chart #1 ApH ±
6.13
6.12
6.06
6.05
6,07
6.04
6.00
5.99
5.96
5.77
5.40
5.21
5.34
5.07
5.40
5.54
5.76
5.74
0.03+
0.02+
0.06+
0.05+
0.02+
0.02+
0.04+
0.01-
0.06+
0.08+
0.05+
0.01+
0.01-
0.12+
0.05+
0.01-
0.04-
0.04+
Standard
Meter #2
6.23
6,22
6.14
6.13
6.17
6.08
6.08
6.06
6.01
5.82
5.52
5.36
5.48
5.12
5.51
5.73
5.92
5.83
II«__BH_I*«««MM«MI>II
1
r
Chart #2 ApH ±
6.22
6.19
6.10
6.11
6.09
6.13
6.04
6.03
5,98
6.06
5.44
5.41
5.44
5.44
5.46
5.73
5.88
5.80
0.01-
0.03-
0.04-
0.02-
0.08-
0.05+
0.04-
0.03-
0.03-
0.24+
0.08-
0.05+
0.04-
0.32-
0.05-
0.00
0.04-
0.03-
----- _ - - - - -- -.....- 1 1 1 1 .
Lab
leasurements ApH ± ApH ± ApH ±
#3 (#2-#l) (#3-#l) (#3-#2)
5.88
5.86
5.82
5.81
5.85
5.76
5.80
5.80
5.70
5.47
5.16
5.00
5.20
4.72
5.03
5.30
5.53
5.38
0.13+
0.12+
0.14+
0.13+
0.12+
0.06+
0.12+
0.06+
0.11+
0.13+
0.17+
0.16+
0.13+
0.17+
0.16+
0.18+
0.12+
0.13+
0.22-
0.24-
0.18-
0.19-
0.20-
0.26-
0.16-
0.20-
0.20-
6.22-
0.19-
0.20-
0.15-
0.23-
0.32-
0.25-
0.27-
0.32-
0.35-
0.36-
0.32-
0.32-
0.32-
0.32-
0.28-
0.26-
0.31-
0.35-
0.36-
0.36-
0.28-
0.40-
0.48-
0.43-
0.39-
0.45-
"in cases with no meter readings, the ApH arithmetic average (difference between meter vs. chart readings)
was added/subtracted from the chart readings.
-------
TABLE B. DATA FROM pH ELECTRODE EVALUATION TEST (pH UNITS) (Continued)
en
en
"^ 1 **^ ^BHOIHriH
Self-Cleaning
Date Time Meter #1
4-7 100
300
500
700
900
1100
1300
1500
1700
1900
2100
2300
4-8 100
300
500
700
900
1100
5.55
5.31
5.16
5.30
5.25
5.40
5.53
5.65
5.70
5.30
5.37
5.50
5.47
5.50
5.37
5.35
5.33
5.35
Chart #1
5.57
5.34
5.21
5.30
5.27
5.40
5.51
5.67
5.72
5.31
5.37
5.49
5.50
5.48
5.38
5.39
5.33
, 5.40
ApH ±
0.02+
0.03+
0.05+
0
0.02+
0
0.02-
0.02+
0.02+
0.01+
0
0.01-
0.03+
0.02-
0.01+
0.04+
0
0.05+
lllil.lilllll«|-«M«-n . ^-^ll
Standard
Meter #2
5.68
5.50
5.38
4.98
5,43
5.53
5.63
5.77
5.76
5.41
5.52
5.64
5.63
5.70
5.58
5.55
5.52
5.57
1
Chart #2 ApH ±
5.63
5.44
5.34
5.38
5.49
5.56
5.74
5,65
5.36
5.49
5.58
5.59
5.64
5.53
5.50
5.47
5.50
0.05-
0.06-
0.04-
0.05-
0.04-
0.07-
0.03-
0.11-
0.05-
0.03-
0.06-
0.04-
0.06-
0.05-
0.05-
0.05-
0.07-
Lab
Measurements ApH ± ApH ± ApH ±
#3 (I2HP1) (#3-#l) (13-12)
5.24
5.05
4.78
5.07
5.03
5.11
5.31
5.36
5.40
5.07
5.78
5.16
5.16
5.07
5.01
5.10
5.11
5.16
0.13+
0.19+
0.22+
0.32-
0.18+
0.13+
0.10+
0.12+
0.06+
0.11+
0.15+
0.14+
0.16+
0.20+
0.21+
0.20+
0.19+
0.22+
0.32-
0.25-
0.38-
0.23-
0.22-
0.29-
0.22-
0.29-
0.30-
0.23-
0.41+
0.34-
0.31-
0.43-
0.36-
0.25-
0.41-
0.19-
0.44-
0.45-
0.60-
0.09+
0.40-
0.42-
0.32-
0.41-
0.36-
0.34-
0.26+
0.48-
0.47-
0.63-
0.57-
0.45-
0.60-
0.41-
*In cases with no meter readings, the ApH arithmetic average (difference between meter vs. chart readings)
was added/subtracted from the chart readings,
-------
TABLE B. DATA FROM pH ELECTRODE EVALUATION TEST (pH UNITS) (Continued)
01
Self -Cleaning
Date Time
4-8 1300
cont 1500
1700
1900
2100
2300
4-9 100
300
500
.700
900
1100
1300
1500
1700
1900
2100
2300
Meter #1
5.45
5.45
5.50
5.45
5.30
5.45
*
5.50
5.55
5.50
5.60
5.65
5.65
5.65
5.65
5.55
5.45
5.35
*
Chart #1 ApH ±
5.47
5.48
5.52
5.49
5.35
5.47
5.47
5.52
5.58
5.55
5.60
5.67
5.67
5.68
5.69
5.57
5.46
5.37
0.02+
0.03+
0.02+
0.04+
0.05+
0.02+
0.02+
0.03+
0.05+
0
0.02+
0.02+
0.03+
0.04+
0.02+
0.01+
0.02+
Standard
Meter 12
5.62
5.64
5.64
5.63
5.54
5.65
*
5.73
5.76
5.73
5.73
5.78
*
5.77
5.80
5.67
5.55
5.49
i i i
1
r
Chart #2 ApH ±
5.58
5.58
5,58
5.57
5.50
5.58
5.61
5.68
5.73
5.69
5.68
5.73
5.73
5.73
5.74
5.63
5.51
5.44
0.04-
0.06-
0.06-
0.06-
0,04-
0.07-
0.05-
0.03-
0.04-
0.05-
0.05-
0.04-
0.06-
0.04-
0.04-
0.05-
Lab
Measurements ApH ± ApH ± ApH ±
#3 (12-11) (13-11) (13-12)
5.22
5.49
5.36
5.19
5.06
5.11
5.12
5.12
5.14
5.18
5.39
5.42
5.41
5.28
5.32
5.31
5.18
5.18
0.17+
0.19+
0.14+
0.18+
0.24+
0.20+
0.21+
0.23+
0.21+
0.23+
0.13+
0.13+
0.12+
0.12+
0.15+
0.12+
0.10+
0.14+
0.23-
0.04+
0.14-
0.26-
0.24-
0.34-
0.32-
0.38-
0.41-
0.32-
0.21-
0.23-
0.24-
0.37-
0.33-
0.24-
0.27-
0.17-
0.40-
0.15-
0.28-
0.44-
0.48-
0.54-
0.53-
0.61-
0.62-
0.55-
0.34-
0.36-
0.36-
0.49-
0.48-
0.36-
0.37-
0.31-
*In cases with no meter readings, the ApH arithmetic average (difference between meter vs. chart readings)
was added/subtracted from the chart readings.
-------
TABLE B. DATA FROM pH ELECTRODE EVALUATION TEST (pH UNITS) (Continued)
en
Self -Cleaning
Date Time
4-10 100
300
500
700
900
1100
1300
1500
1700
1900
2100
2300
4-11 100
300
500
700
900
1100
Meter #1
5.25
5.25
5.30
5.35
5.43
5.55
5.95
6.27
5.92
5.85
5.85
5.94
6.02
6.15
6.15
6.15
5.95
5.97
Chart #1 ApH ±
5.28
5.27
5.33
5.38
5.44
5.51
6.00
6.33
5.94
5.89
5.86
5.97
6.07
6.15
6.16
6.17
5.97
6.00
0.03+
0.02+
0.03+
0.03+
0.01+
0.04-
0.05+
0.06+
0.02+
0.04+
0.01+
0.03+
0.05
0
0.01+
0.02+
0.02+
0.03+
Standard
Meter 12
5.42
5.41
5.43
*
5.53
5.62
5.66
5.66
5.67
5.81
5.85
5.96
6.03
6.07
6.10
6.14
5.97
5.97
Chart #2 ApH ±
5,38
5.38
5.38
5.44
5.49
5.56
5.62
5.63
5.65
5.77
5.80
5.92
5.99
6.04
6.08
6.11
5.94
5.94
0.04-
0.03-
0.05-
0.04-
0.06-
0.04-
0.03-
0.02-
0.04-
0.05-
0.04-
0.04-
0.03-
0.02-
0.03-
0.03-
O.C3-
I^HMBMBVHB««^VWBIHMM'>ln*IBBMHHB>***^v^H^M^^^H^^^n^b^H<*IIB^HnHH*HIBI*MI'lll*l"IB^
Lab
Measurements ApH ± ApH ± ApH ±
#3 (#2-#l) (#3-#l) (#3-#2)
5.04
4.95
5.02
5.04
5.11
5.15
5.14
5.32
5.37
5.26
5.37
5.52
5.57
5.71
5.73
5.72.
5.48
5.61
0.17+
0.16-
0.13+
0.13+
0.10+
0.07+
0.29-
0.61-
0.25-
0.04-
0
0.02+
0.01+
0.08-
0.05-
0.01-
0.02+
0
0.21-
0.30-
0.28-
0.31-
0.32-
0.40-
0.81-
0.95-
0.55-
0.59-
0.48-
0.42-
0.45-
0.44-
0.42-
0.43-
0.47-
0.36-
0.38-
0.46-
0.41-
0.44-
0.42-
0.47-
0.52-
0.34-
0.30-
0.55
0.48-
0.44-
0.46-
0.36-
0.37-
0.42-
0.49-
0.36-
*In cases with no meter readings, the ApH arithmetic average (difference between meter vs. chart readings)
was added/subtracted from the chart readings.
-------
TABLE B. DATA FROM pH ELECTRODE EVALUATION TEST (pH UNITS) (Continued)
00
' ' 1 III
Self -Cleaning
Date Time
4-11
cont 1300
1500
1700
1900
2100
2300
4-12 200
400
600
700
900
1100
1300
1500
1700
1900
2100
2300
Meter #1
6.15
6.05
6.30
6.32
6.25
6.42
6.50
6.45
6.50
6.60
6.55
6.35
6.10
Chart #1 ApH ±
6.07
6.06
6.34
6.35
6.33
6.46
6.54
6.48
6.57
6.60
6.60
6.41
6.15
0.08-
0.01+
0,04+
0.03+
0.08+
0.04+
0.04+
0.03+
0.07+
0.0
0.05+
0.06+
0.05+
. ~ I !». J^M^MI
Standard
Meter #2
5.98
6.01
6.05
6.08
6.16
6.20
6.19
6.20
6.21,
6.21
6.20
6.00
5.52
5.46
5.63
5.65
5.82
6.06
^IIM^H^taVMMMaWI^Hafe^HWV
1
i
Chart #2 ApH ±
5.98
5.97
6.02
6.07
6.15
6,17
6,16
6.16
6.15
6.18
6.16
5.92
5.46
5.39
5.60
5.63
5.85
6.09
0
0.04-
0.03-
0.01-
0.01-
0.03-
0,03-
0.04-
0.06-
0.03-
0.04-
0.08-
0.06-
0.07-
.0.03-
0.02-
0.03+
0.03+
Lab
Measurements ApH ± ApH ± ApH ±
#3 (#2-#l) (#3-11) (#3-#2)
5.69
5.42
5.59
5,71
5.74
5.79
5.82
5,80
5.82
5.66
5.83
5.65
5.08
5.04
5.22
4.90
5.02
5.77
0.17-
0.04-
0.25-
0.24-
0.09-
0.22-
0.31-
0.25-
0.29-
0.39-
0.35-
0.35-
0.58-
0.46-
0.63-
0.71-
0.61-
0.51-
0.63-
0.68-
0.65-
0.68-
0.94-
0.72-
0.76-
1.02-
0.29-
0.59-
0.46-
0.37-
0.42-
0.41-
. 0.37-
0.40-
0.39-
0.55-
0.37-
0.35-
0.44-
0.42-
0.41-
0.75-
0.80-
0.29-
*In cases with no meter readings, the ApH arithmetic average (difference between meter vs. chart readings)
was added/subtracted from the chart readings.
-------
TABLE B. DATA FROM pH ELECTRODE EVALUATION TEST (pH UNITS) (Continued)
en
Date
4-13
4-14
"" " ' ' ' II II 1 ..- !! ««IIIMIIII. . HI..HIH.
Self-Cleaning
Time Meter #1 Chart #1 ApH ±
100
300
500
700
900
1100
1300
1500
1700
1900
2100
2300
100
300
500
700
900
1100
..IM- ^^.^.^M
Standard
Meter 12
6,08
6.09
6.00
5.95
5.98
5.57
5.99
5.62
5.87
5.70
5,69
5.91
5.98
5.99
5.76
5.63
5.66
5.74
Chart %
6.03
6.04
5.97
5,94
5,56
5,52
5.54
5.57
5.80
5.67
5,66
5.56
5.92
5.92
5.68
5.57
5,61
5.71
MVMMM«MMV^BMWB^-«-
!2 ApH ±
0.05-
0.05-
0.03-
0,05-
0.42-
0.05-
0.05-
0.05-
0.07-
0.03-
0.03-
0.35-
0.06-
0.07-
0.08-
0.06-
0.05-
0.03-
Lab
leasurements ApH ± ApH ± ApH ±
#3 (12-11) (13-11) (13-12)
5.42.
5.56
5.47
5.52
5.11
5.12
5.09
5.03
5.43
5.11
5.02
5.26
0.66-
0.53-
0.53-
0.43-
0.87-
0.45-
0.50-
0.59-
' 0.44-
0.59-
0.67-
0.65-
*In cases with no meter readings, the ApH arithmetic average (difference between meter vs. chart readings)
was added/subtracted from the chart readings.
-------
TABLE B. DATA FROM pH ELECTRODE EVALUATION TEST (pH UNITS) (Continued)
Date
4-14
cont
4-15
Self -Cleaning
Time Meter #1 Chart #1 ApH ±
1300
1500
1700
1900
2100
2300
100
300
500
- 700
900
1100
1300
1500
1700
1900
2100
2300
.- ^ ^ i i ^ . i muuii i
Standard
Meter #2
5
5
5
5
5
6
5
5
5
5
5
5
5
5
5
5
5
5
.74
.79
,73
.76
.89
.01
.96
.68
,78
.81
.78
,81
.61
,62
.71
.83
.90
.76
Chart #2
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
.79
,75
.68
.72
.87
.93
.92
.67
.73
,77
,73
.75
.56
.59
.67
.79
.86
.74
^WW^»^M^^^H
U
ApH ±
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
05+
04-
05-
04-
02-
08-
04-
01-
05-
04-
05-
06-
05-
03-
04-
04-
04-
02-
Lab
leasurements ApH ± ApH ± ApH ±
#3 (12-11) (13-11) (13-12)
5
5
5
5
5
5
5
5
5
5
5
5
.43
.14
.24
.19
.27
.33
.15
.08
.02
.29
.37
.05
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
53-
54-
54-
62-
51-
48-
46-
54-
69-
54-
53-
71-
*In cases with no meter readings, the ApH arithmetic average (difference between meter vs. chart readings)
was added/subtracted from the chart readings.
-------
TABLE fr. DATA FROM pH ELECTRODE EVALUATION TEST (pH UNITS) (Continued)
^WMMMMi
Date
4-16
4-17
II. II.H. .1- ........ . ,,,,.,| 1 .11 1 . 1. ,.....,......
Self-Cleaning
Time Meter #1 Chart #1 ApH ±
100
300
500
700
900
1100
1300
1500 5.87
1700
1900
2100
2300
100
300
500
700
900
1100
.^^^^^^^^j^j^^^^n, .», mmm amimmmtm, m
Standard
Meter 12
5.82
5.78
5.66
5.68
5.78
5.96
5.80
5.68
Chart #2
5.80
5.76
5.62
5.63
5.75
5.93
5.74
5.62
^^^MH
,. N
ApH ±
0.02-
0.02-
0.04-
0.05-
0.03-
0.03-
0.06-
0.06-
Lab
leasurements ApH ± ApH ± ApH ±
#3 (12-11) (13-11) (13-12)
5,33
5.32
5.17
5.04
5.22
5.30
5.20
5.01
0.51-
0.46-
0.49-
0.64-
0.56-
0.66-
0.60-
0.67-
.
-
*In cases with no meter readings, the ApH arithmetic average (difference between meter vs. chart readings)
was added/subtracted from the chart readings,
-------
TABLE B. DATA FROM pH ELECTRODE EVALUATION TEST (pH UNITS) (Continued)
ro
Date
4-17
cont
4-18
-"' ' - ' ' i . i .1 m i i i
Self-Cleaning
Time Meter #1 Chart #1 ApH ±
1300
1500
1700
1900
2100
2300
100
300
500
700
900
1100
1300
1500
1700
1900
2100
2300 6.30
.1. II 1 II 1 1 II 1 ! I..I. II . . .,! 1 1 -1 1 1 1 II III. 1 1 l« '"- " ' ' " "
Standard Lab
MM.« «»..u.*t.M«tM4-*» A Mil a. A nU .L. AnU 4-
" ' " " Measurements Apn ± Apn z Apn x
Meter #2 Chart #2 ApH ± #3 (12-11) (#3-#l) (#3-#2)
7.60
6.13 6.10 0.03- 5.45 0.68-
6.27 6.22 0.05- 5.56 0.03- 0.74- 0.71-
*In cases with no meter readings, the ApH arithmetic average (difference between meter vs. chart readings)
was added/ subtracted from the chart readings.
-------
TABLE B.. DATA FROM pH ELECTRODE EVALUATION TEST (pH UNITS) (Continued)
CO
Self-Cleaning
Standard
Date Time Meter #1 Chart #1 ApH ± Meter 12
4-19 100 6.35
300 6.40
500 6.45
700 6.55
x 900 6.55
1100 OUT
1300 OUT
1500 OUT
1700
1900
2100
2300
4-20 100
300
500
700
900
1100
6.31
6.17
6.21
6.29
6.24
6.24
6.24
6.22
6.21
6.24
6.33
6.31
*
*
*
6.07
5.58
5.51
Chart #2 ApH ±
6,28
6.18
6.22
6.22
6.22
6.22
6,21
6.21
6.18
6.22
6.29
6.29
6.34
6.35
6.07
6.05
5.44
5.47
0.03-
0,01+
0,01+
0.07-
0.02-
0.02-
0.03-
0.01-
0.03-
0.02-
0.04-
0.02-
0.02-
0.14-
9.04-
Lab
Measurements ApH ± ApH ± ApH ±
#3 (#2-#l) (13-11) (13-12)
5.47 -
5.58
5.68
5.45
5.36
5.55
5.49
5.66
5.59
5.52
5.52
5,50
5.53
5.60
5.56
5.49
5.66
5.14
0.04- 0.88- 0.84-
0.23- 0.82- 0.59-
0.24- 0.77- 0.53-
0.26- 1.10- 0.84-
0.31- 1.19- 0.88-
0.69-
0.75-
0.56-
' 0.62-
0.72-
0.81-
0.81-
0.85-
0.79-
0.55-
0.58-
0.92-
0.37-
In cases with no meter readings, the ApH arithmetic average (difference between meter vs. chart readings)
was added/subtracted from the chart readings.
-------
TABLE
Self-Cleaning
Date
4-20
cont
4-21
Time
1300
1600
1700
1900
2100
2300
100
300
500
.700
900
1100
1300
1500
1700
1900
2100
2300
'iiliiiimii^^gniaHJiii i i n
Standard
Meter #1 Chart #1 ApH ± Meter 12
5.
5.
5.
5.
5.
5.
5.
5.
5.
5.
5.
5.
-4.
5.
50
36
45
60
5Q
30
05
10
15
10
10
05
90
10
5
5
5
5
5
5
5
5
*
5
5
5
5
5
5
5
5
5
.49
.47
.47
.49
.49
.45
.41
.40
.30
.28
.58
.25
.20
.18
.21
.29
.32
IMHIMHMIIBMB^^HV^HBMlMMMHIlM
1
' |
Chart #2 ApH ±
5.44
5.44
5.43
5.46
5,45
5.40
5.35
5.35
5.29
5.26
5.25
5.53
5.21
5.16
5.14
5.13
5.18
5.27
0.05-
0.03-
0.04-
0.03-
0.04-
0.05-
0,06-
0.05-
*
0.04-
0.03-
0.05-
0.04-
0.04-
0.04-
0.08-
0.11-
0.05-
Lab
Measurements ApH ± ApH ± ApH ±
#3 (12-11) (13-11) (13-12)
5.55
5.58
5.52
5.56
5.55
5.48
5.45
5.45
5.39
5.22
5.18
5.13
5.25
5.26
5.15
5.07
5.23
5.05
0.03-
0.11+
0.04+
0.11-
0.05-
0.11+
0.35+
0.23+
0.10+
0.10+
0.08+
0.16+
0.39+
0.22+
0.08+
0.16+
0.11+
0.05-
0.02-
0.15+
0.40+
0.29+
i
.10+
0.16+
0.05+
0.02+
0.33+
0.05-
0.06+
0.11+
0.05+
0.07+
0.06+
0.03+
0.04+
0.05+
0.06+
0.08-
0.10-
0.45-
0
0.06+
0.03-
0.14-
0.06-
0.27-
*In cases with no meter readings, the ApH arithmetic average (difference between meter vs. chart readings)
was added/subtracted from the chart readings.
-------
TABLE B. DATA FROM pH ELECTRODE EVALUATION TEST (pH UNITS) (Continued)
en
Self-Cleaning Standard
Date Time Meter #1 Chart #1
4-22 100
300
500
700
900
1100
1300
1500
1700
1900
2100
2300
4-23 100
300
500
700
900
1100
5.10
5.05
4.95
4.85
4.85
4.92
4.84
4.95
5.19
5.20
5.15
5.10
5.15
5.10
5.00
4.91
4.92
4.95
ApH ± Meter 12
5.35
*
*
5.30
5,15
5.15
5.20
*
*
*
*
*
*
*
*
*5.25
*5.82
*5.81
Chart #2 ApH ±
5.32 0.03-
5.35
5.27
5.21 0.09-
5.14 0.01-
5.11 0.04-
5,20 0
5.37
5.43
5.50
5.49 '
5. '47
5.47
5.40
5.39
5.35
6.22
5.40
Lab
Measurements ApH ± ApH ± ApH ±
13 (12-11) (13-11) (13-12)
5.16
5.35
5.26
5.20
5.21
5.05
5.02
5.16
5.22
5.56
5.54
5.59
5.45
5.35
5.36
5.39
5.26
5.51
0.25+
0.34+
0.36+
0.45+
0.30+
0.23+
0.36+
0.46+
0.28+
0.34+
0.38+
0.41
0.36+
0.34+
0.43+
0.48+
1.34+
0.49+
0.06+
0.30+
0.31+
0.35+
0.36+
0.13+
0.18+
0.21+
0.03+
0.36+
0.39+
0.49+
0.30+
0.25+
0.36+
0.48+
0.34+
0.56+
0.19-
0.04-
0.05-
0.10-
0.06+
0.10-
0.18-
0.25-
0.25-
0.02+
0.01+
0.08+
0.06-
0.09-
0.07-
0.00
1.00-
0.07+
*In cases with no meter readings, the ApH arithmetic average (difference between meter vs. chart readings)
was added/subtracted from the chart readings.
-------
TABLE B. DATA FROM pH ELECTRODE EVALUATION TEST (pH UNITS) (Continued)
Self-Cleaning Standard
Date Time
con? 130°
1500
1700
1900
2100
2300
4-24 100
300
500
700
900
1100
1300
1500
1700
1900
2100
2300
Meter #1 Chart #1 ApH ± Meter #2
4.95
4.90
4.80
4.90
5.00
5.05
5.07
5.00
4.95
4.80
4.90
5.05
5.20
5.20
5.20
5.15
5.15
'5.12
*5.82
*5.83
*5.86
*5.91
*5.96
*6.01
*6.08
*6,09
*6.08
*6.04
*6.04
*6.11
*6.14
*6.06
*6.08
*6.06
*6.14
*
Chart #2 ApH ±
5,35
5.31
5,27
5.32
5,42
5.38
5.38
5.35
5.27
5.15
4.96
5.37
5.50
5.50
5.50
5.49
5,47
5.45
Lab
Measurements ApH ± ApH ± ApH ±
#3 (#2-#l) (#3-#l) (#3-#2)
5.40
5.40
5.33
5.07
5.15
5.33
5.23
5.33
5.25
5.21
5.43
5.34
5.47
5.58
5.67
5.59
5.54
5.52
0.44+
0.45+
0.51+
0.46+
0.46+
0.37+
0.35+
0.39+
0.36+
0.39+
0.10+
0.36+
0.34+
0.34+
0.34+
0.38+
0.35+
-.. .. ...
0.34+
0.45+
0.50+
0.53+
0.17+
0.15+
0.28+
0.16+
0.33+
0.30+
0.41+
0.53+
0.29+
0.27+
0.38+
0.47+
0.44+
0.39+
0.40+
0.01+
0.05+
0.02+
0.29-,
0.31-
0.09-
0.19-
0.06-
0.06-
0.02+
0.43+
P. 07-
0.07+
0.04+
0.13+
0.06+
0.03+
0.06+
*In cases with no meter readings, the ApH arithmetic average (difference between meter vs. chart readings)
was added/subtracted from the chart readings.
-------
TABLE B. DATA FROM pH ELECTRODE EVALUATION TEST (pH UNITS) (Continued)
' "' ' "' i.i. j .. n . .,. .,. .,-,-,....,.., i. - . M i .-....
Sel f -C1 eani ng Standard
Date Time Meter #1 Chart #1
4-25 100
300
500
700
900
1100
1300
1500
1700
1900
2100
2300
4-26 100
300
500
700
900
1100
5.00
4.92
4.90
5.00
5.05
5.15
5.10
5.15
5.05
4.85
4.70
4.70
4.75
4.90
5.05
4.95
5.00
5.10
ApH ± Meter #2
*6.11
*6,00
*
*
*
6.06
6.16
6.24
6.26
6.27
6.10
6.03
5.99
5.95
5.89
5.75
5.67
5.61
^(MB*
1
1 " r
Chart #2 ApH ±
5.37
5.32
5.47
5.39
5.75
5.94
5.94
5.95
5.97
5.99
6.02
6.10
5.86
5.86
5.89
5.92
5.48
5.51
0.08-
0.22-
0.29-
-0.29-
0.28-
0.08-
0.07+
0.13-
0.09-
0
0.17+
0.19-
0.10-
Lab
Measurements ApH ± ApH ± ApH ±
#3 (12-11) (I3-I1J (13-12)
5.41
5.28
5.22
5.33
5.36
5.66
5.58
5.52
5.47
5.39
5.30
5.06
5.15
5.48
5.53
5.37
5.45
5.66
0.41+
0.44+
0.61+
0.40+
0.74+
0.91+
1.06+
1.09+
1.21+
1.42+
1.40+
1.33+
1.24+
1.05+
0.84+
0.80+
0.67+
0.51+
0.41+
0.36+
0.32+
0.33+
0.31+
0.51+
0.48+
0.37+
0.42+
0.54+
0.60+
0.36+
0.40+
0.58+
0.48+
0.42+
0.45+
0.56+
0.00
0.08-
0.29-
0.07-
0.43-
0.40-
0.58-
0.72-
0.79-
0.88-
0.80-
0.97-
0.84-
0.47-
0.36-
0.38-
0.22-
0.05+
kln cases with no meter readings, the ApH arithmetic average (difference between meter vs. chart readings)
was added/subtracted from the chart readings,
-------
TABLE B. DATA FROM pH ELECTRODE EVALUATION TEST (pH UNITS) (Continued)
00
Self-Cleaning
Date
4-26
cont
4-27
Time
1300
1500
1700
1900
2100
2300
100
300
500
700
900
1100
1300
1500
1700
1900
2100
2300
» »a».«^»..i....»i^»^»M.
Standard
Meter #1 Chart #1 ApH ± Meter #2
5
5
4
4
4
4
4
4
4
4
4
4
5
6
5
5
.15
.15
.85
.70
.65
.58
.52
.45
.54
.55
.70
.80
.76
.00
.70
.40
5
5
5
*
*
5
5
5
5
5
5
5
6
6
6
5
5
.64
.75
.86
.12
.11
,03
.12
.13
.27
.26
.22
.17
.08
.85
.87
^^^wiMVAa
U_
1 me
Chart #2 ApH ±
5.54
5,41
5,23
5.15
5.11
5.08
5.05
4.98
5,05
5.09
5.20
5.20
5.32
6.16
6.10
6.10
5.89
0.10-
0.34-
0.63-
0.04-
0,06-
0.05-
0.07-
0.04-
0.07-
0.06-
0.90-
0.01-
0.02+
0.25+
0.02+
- - - 1 ' ' 1 '
Lab
asurements ApH ± ApH ± ApH ±
#3 (12-11) (13-11) (13-12)
5.71
5.49
5.42
5.16
5,24
4.98
5.19
5.08
5.09
5.12
5.32
5.20
6.62
6.34
6.46
6.23
5.89
0.49+
0.60+
1.01+
0.49+
0.50+
0.54+
0.59+
0.58+
0.58+
0.58+
0.57+
0.46+
0.41+
0.08+
0.15+
0.47+
0.56+
0.34+
0.57+
0.46+
0.59+
0.40+
0.67+
0.63+
0.55+
0.57+
0.62+
0.40+
0.58+
0.46+
0.53+
0.49+
0.07+
0.26-
0.44-
0.03-
0.09+
0.14-
0.08+
0.05+
0.03-
0.01-
0.05+
0.06-
0.40+
0.17+
0.38+
0.38+
0.02+
In cases with no meter readings, the ApH arithmetic average (difference between meter vs. chart readings)
was added/subtracted from the chart readings.
-------
TABLE B. DATA FROM pH ELECTRODE EVALUATION TEST (pH UNITS) (Continued)
ov
1C
' - -
Self -Cleaning
Date Time Meter #1 Chart #1
4-28 100
300
' 500
700
900
1100
1300
1500
1700
1900
2100
2300
4-29 100
300
500
700
900
1100
5.25
5.85
6.00
6.41
5.98
5.85
5.85
5.50
6.00
6.27
5.30
5.90
5.70
5.05
6.35
VM^BW^aaVaB^Wn ««M*^M« ««*«Mi>««
Standard
ApH ± Meter #2
5
5
5
6
6
*
5
5
6
6
5
5
7
5
5
6
5
6
.32
.87
,94
.84
.33
.89
.48
.05
.44
.37
.74
.30
.01
.92
.06
.40
.7
HMK^MVHHHBV^H^^H
1
Chart #2 ApH ±
5.98
6.04
6.16
6.25
6.40
6.40
6.19
5.89
6.16
6.04
5.92
6.16
6.22
4.96
5.91
5.92
5.26
6.10
0.
0.
0.
0.
0.
0.
0.
-o.
0.
0.
0.
1.
0.
0.
0.
0.
0.
66+
17+
22+
59-
07+
30+
41+
11+
44-
55+
42+
12-
05-
01-
06-
14-
6-
Lab
Measurements ApH ± ApH ± ApH ±
#3 (#2-#l) (#3-#l) (#3-#2)
5.66
6.02
6.18
6.66
6.30
6.33
6.20
5.88
6.25
6.55
5.69
5.80
6.79
5.46
6.12
6.02
5.58
6.50
0
0
0
0
0
0
0
0,
0,
0,
0.
0.
0.
0.
0.
.07+
.02+
.06-
.43+
.35+
.59+
.04+
.02-
.05+
.17+
.07+
02+
36+
35+
35+
0.41+
0.17+
0.18+
0.25+
0.32+
0.48+
0.35+
0.38+
0.25+
0.28+
0.39+
0.22+
0.32+
0.53+
0.15+
0.34+
0-15+
0.24+
0.18-
0.03-
0.11-
0.31+
- 0.40+
0.20+
0.11+
0.32+
0.06+
0.51-
0.45+
0.20+
0.04-
0.18+
0.20-
"In cases with no meter readings, the ApH arithmetic average (difference between meter vs. chart readings)
was added/subtracted from the chart readings.
-------
TABLE B. DATA FROM pH ELECTRODE EVALUATION TEST (pH UNITS) (Continued)
-4
O
Self-Cleaning
Date Time Meter #1 Chart #1
4-2Q
con? 130°
1500
1700
1900
2100
2300
4-30 100
300
500
700
900
1190
1300
1500
1700
1900
2100
2300
5.40
5.25
6.05
5.90
5.65
6.00
5.60
6.20
6.30
6.50
6.05
5.60
6.35
6.55
6.00
5.90
5.90
5.80
ApH ± Meter
5.72
5.59
6.16
6.00
5.80
6.21
NEW
5.83
6.16
6.29
6.26
6,20
5.50
6.34
6,75
5.82
5.72
5.87
5.55
Standard
u
r
12 Chart #2 ApH ±
5,80
5.74
6.16
6.10
6.10
6.34
RECORDER
5.90
6.00
5,85
6.21
6.28
5.43
6.15
6.40
5.60
5.60
5,70
5.55
0.08+
0.15+
0
0.10+
0.30+
0.13+
0.07+
0.16-
0.44-
0.05-
0.08+
0.07-
0.19-
0.35-
0.22-
0.12-
0.17-
0
Lab
leasurements ApH ± ApH ± ApH ±
#3 (#2-#l) (#3-#l) (#3-#2)
5.70
5.83
6.23
6.05
6.00
6.25
5.98
6.33
6.45
6.46
6.25
5.94
6.57
6.88
6.14
5.99
6.15
5.98
0.32+
0.34+
0.11+
0.10+
0.15+
0.21+
0.23+
0.04-
0.01-
0.30-
0.15+
0.10-
0.01-
0.20+
0.18-
0.18-
0.03-
0.25-
0.30+
0.58+
0.18+
0.15+
0.35+
0.25+
0.38+
0.13+
0.15+
0.04-
0.20+
0.34+
0.22+
0.33+
0.14+
0.09+
0.25+
0.18+
0.02-
0.24+
0.07+
0.05+
0.20+
0.04+
0.15+
0.17+
0.16+
0.26+
0.05+
0.44+
0.23+
0.13+
0.32+
0.27+
0.28+
0.43+
In cases with no meter readings, the ApH arithmetic average (difference between meter vs. chart readings)
was added/subtracted from the chart readings.
-------
TABLE H. DATA FROM pH ELECTRODE EVALUATION TEST (pH UNITS) (Continued)
Self-Cleaning
Date Time Meter #1 Chart #1
5-1 100
300
500
700
900
1100
1300
1500
1700
1900
2100
2300
5-2 100
300
500
700
900
1100
5.50
5.85
5.75
5.90
5.75
6.11
6.04
6.20
6.20
6.05
6.00
5.75
5.85
5.95
6.10
6.10
5.90
5.93
Standard
ApH ± Meter 12
5
5
5
5
5
5
5
5
5
5
5
5
5
5
6
5
5
5
,28
.99
.66
,69
.83
,97
,89
.92
.73
.47
.54
.60
.51
.89
.05
.97
.73
.54
I
Chart n ApH ±
5.50
6.30
5.49
5.50
6,35
5.21
5.73
5.70
5.50
5.30
5.37
5.45
5.50
5.60
5.80
5.97
5.31
5.47
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
.22+
.31+
.17-
.19-
.48-
.76-
.16-
.22-
.23-
.17-
.17-
.15-
.01-
.29-
.25-
.42-
.07-
Lab
Measurements ApH ± ApH ± ApH ±
#3 (12-11) (13-11) (13-12)
5.63
5.77
6.04
6.
,25
5.92
6.
6.
6.
6.
6.
5.
6.
6.
6.
6.
6.
6.
6.
39
20
24
13
16
95
02
05
03
23
13
10
06
0.22-
0.14+
0.09-
0.21-
0.08+
0.14-
0.15-
0.28-
0.47-
0.58-
0.46-
0.15-
0.34-
0.06-
0.05-
0.13-
0.17-
0.39-
0.13+
0.08-
0.29+
0.35+
0.17+
0.28+
0.16+
0.04+
0.07-
0.11+
0.05-
0.27+
0.20+
0.08+
0.13+
0.03+
0.20+
0.13+
0.35+
0.22-
0.38+
0.56+
0.09+
0.42+
0.31+
. 0.32+
0.40+
0.69+
0.41+
0.42+
0.54+
0.14+
0.18+
0.16+
0.37+
0.52+
cases with no meter readings, the ApH arithmetic average (difference between meter vs. chart readings)
i added/subtracted from the chart readings.
was
-------
TABLE B. DATA FROM pH ELECTRODE EVALUATION TEST (pH UNITS) (Continued)
Date Time
5-2 1300
cont 1JUU
1500
1700
1900
2100
2300
5-3 100
300
500
700
900
1100
1300
1500
1700
1900
2100
2300
Self -Cleaning
Standard
Meter 11 Chart #1 ApH ± Meter #2
5.79
5.80
.6.10
6.05
6.00
5.70
5.90
6.35
6.30
5.75
5.97
5,42
5.45
6,10
5.81
5.85
5.42
5,70
6.40
6.47
5.45
5.69
6.18
5.33
5.72
5.37
6.27
5.41
5.44
Chart #2 ApH ±
5.70
5.40
5.87
5.60
5.50
5.25
5.57
5.80
5,95
5.40
5.20
5.60
5.20
5.40
5.80
6.15
5.20
5.70
0.28+
0.05-
0.23-
0.21-
0.35-
0.17-
0.27-
0.60-
0.52-
.0.05-
0.49-
0.58-
0.13-
0.32-
0.43+
0.12-
0.21-
0.26+
Lab
Measurements ApH ± ApH ± ApH ±
#3 (12-11) (#3-#l) (#3-#2)
6,03
5.93
6.38
6.13
6.18
5.80
6.04
6.49
6.19
5.95
5.93
6.62
5.63
6.16
5.86
6.47
6.04
6.05
0.37-
0.35-
0
0.24-
0.15-
0.28-
0.20-
0.05+
0.17+
0.30-
0.28-
0.24+
0.13+
0.28+
0.08+
0.18+
0.10+
0.14+
0.14+
0.11-
0-.20+
0.04-
0.61+
0.48+
0.28+
0.32+.
0.33+
0.38+
0.34+
0.09+
0.28-
0.50+
0.24+
0.44+
0.30+
0.44+
0.49+
0.20+
0.63+
0.61+
"in cases with no meter readings, the ApH arithmetic average (difference between meter vs. chart readings)
was added/subtracted from the chart readings.
-------
REPORT NO.
EPA-600/2-79-202
TITLE AND SUBTITLE
The Use of pH and Chloride Electrodes for the Auto-
matic Control of Flue Gas Desulfurization Systems
TECHNICAL REPORT DATA
(Please read Inunctions on the reverse before completing)
3. RECIPIENT'S ACCESSION NO.
5. REPORT DATE
November 1979
6. PERFORMING ORGANIZATION CODE
Clinton Ung, Toby Acciani, and Ray Maddalone
8. PERFORMING ORGANIZATION REPORT NO.
ERFORMING ORGANIZATION NAME AND ADDRESS
TRW Defense and Space Systems Group
One Space Park
Redondo Beach, California 90278
10. PROGRAM ELEMENT NO.
INE624
11. CONTRACT/GRANT NO.
68-02-2165, Task 220
2. SPONSORING AGENCY NAME AND ADDRESS
EPA, Office of Research and Development
Industrial Environmental Research Laboratory
Research Triangle Park, NC 27711
13. TYPE OF REPORT AND PERIOD COVERED
Task Final; 9/78 - 7/79
14. SPONSORING AGENCY CODE
EPA/600/13
5. SUPPLEMENTARY NOTES JERL-RTP project officer is Frank E. Briden, Mail Drop 62,
919/541-2557.
i6. ABSTRACT The report gives results of a study to determine the applicability of chloride
and pH electrodes in automated control systems. It included a survey of chloride and
pH electrodes in different flue gas desulfurizatiori (FGD) systems and an evaluation
of an industrial pH electrode system. The survey showed that chloride ion measure-
ments were necessary only where high chloride values correspond with FGD unit
corrosion and when chloride values were used as correction factors in pH calcula-
tions. Chloride ion measurements are unnecessary for most of the surveyed compa-
nies. All surveyed companies use pH measurements to control scaling or to attain
optimum performance in FGD units. The most common pH electrode problem was
residue buildup (scaling) around the electrode, caused by the use of non-self-cleaning
(standard) pH electrodes. The performance of self-cleaning and standard industrial
pH electrodes was evaluated at the EPA/TVA Shawnee FGD test facility. The elec-
trodes were tested during a 7-week period with varying durations of continuous oper-
ation. The tests showed that: the performance of self-cleaning and standard elec-
trodes was nearly identical, and the benefits of a self-cleaning pH electrode can
only be realized if electrode scaling is a problem and if a long (2-week) continuous
period of pH electrode operation is maintained.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS
c. COSATl Field/Group
Pollution
Flue Gases
Desulfurization
Automatic Control
Electrodes
PH
Chlorides
Corrosion Prevention
Pollution Control
Stationary Sources
13B 07B
21B 13H
07A,07D
14B
09A
3. DISTRIBUTION STATEMENT
Release to Public
^MHMmHHMMHBMMHUMMM
EPA Form 2220-1 (9-73)
19. SECURITY CLASS (This Report/
Unclassified
73
20. SECURITY CLASS (This page)
Unclassified
22. PRICE
73
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