EPA-AA-EOD-88/2
Temperature Achiever Project Report
Carl M. Paulina
May 1988
-------
Executive Summary
Federal regulations require that automobile manufacturers limit the
evaporative hydrocarbon emissions given off by gasoline-fueled motor
vehicles. To ensure that the manufacturers meet this standard, the Motor
Vehicle Emission Laboratory (MVEL) Vehicle Acquisition and Testing (VAST)
Group perform fuel tank diurnal heat builds as part of the Code of Federal
Regulations (CFR) Federal Test Procedure (FTP), Section 86.133-78 "Diurnal
breathing loss test." These heat builds simulate the temperature rise a
vehicle sees during a day.
The device used to control an electric heat blanket placed on a vehicle
fuel tank to effect these heat builds is called a temperature achiever. This
report summarizes the project which introduced new temperature achievers for
official testing at MVEL between July 1987 and December 1987.
The prototype was designed by the Electronic Support Team (EST) and
evaluated by the Laboratory Projects Group (LPG) prior to introduction into
VA&T. Eleven units were CFR compliance tested before they were approved for
use. A total of twelve units, including the prototype, were introduced.
Data, from compliance tests of the units, indicate that all the new
temperature achievers are capable of performing CFR heat builds in automatic
mode with a comparable repeatability of one degree on 40 CFR 86.133-78
"Diurnal breathing loss test" heat builds for both 13 and 18 gallon fuel tank
vehicles. This performance is anticipated on 93 percent of the vehicles
tested at MVEL.
-------
Temperature Achiever Project Report
Background
Federal regulations require that automobile manufacturers limit the
evaporative hydrocarbon emissions given off by gasoline fueled motor
vehicles. To ensure that the manufacturers meet this standard, the Motor
Vehicle Emission Laboratory (MVEL) Engineering Operations Division (EOD)
Vehicle Acquisition and Testing (VA&T) Group performs fuel tank diurnal heat
builds as part of the Code of Federal Regulations (CFR) Federal Test Procedure,
(FTP). These heat builds simulate the temperature rise a vehicle sees during
a day.
40 CFR 86.133-78 contains the specific details of the required "Diurnal
breathing loss test." The test consists of artificially heating a vehicle
fuel tank in such a way that its temperature change conforms to the following
function within ± 3°F:
F=T+0.4t
where:
F=fuel temperature, °F
t=time since beginning of test, minutes.
T=initial temperature(60°F)
After 60j*2 minutes of heating, the fuel temperature rise shall be 24^1°F.
The device used to control an electric heat blanket placed on a vehicle
fuel tank to effect these heat builds is called a temperature achiever. This
report summarizes the project which introduced new temperature achievers used
for official testing at MVEL between July 1987 and December 1987.
The new temperature achievers use a microprocessor to monitor fuel tank
temperatures and control the fuel temperature rise with time. The
microprocessor compares the fuel tank temperature against time and supplies a
control signal to maintain the above fuel temperature rise ramp.
The new units were introduced both to phase out the older, obsolete units
with more up-to-date electronics and to increase the number of achievers
available for increasing testing demands.
Work Performed
The temperature achievers were designed and manufactured by the EOD
Electronic Support Team (EST). The units have LFE Corporation microprocessors
as the heart of their operation. The microprocessors perform the monitor and
control functions of the heat builds. Power output, to an electric heat
blanket on a vehicle fuel tank, is controlled by an Athena proportional
control relay (SCR). This varies the power output to the heat blanket as
dictated by the microprocessor. The amount of power supplied to the heat
blanket is displayed in percent on the front of the LFE (see Appendix A-5).
The temperature achievers have an indicator lamp, under the LFE front panel
(Appendix A-5) which increases in brightness as power to the heat blanket
increases. For safety, the units also contain an overtemperature shutoff set
-------
to kill blanket power when fuel temperature reaches 90°F. An electrical
schematic and bill of materials for the temperature achiever are contained in
Appendices A-2 and B respectively.
The LFE is programmed with a temperature rise ramp corresponding to the
time and temperature rise equation stated in the CFR (see Appendix A-3). Fuel
temperature from a type J thermocouple, located in a vehicle fuel tank, and
elapsed time are then compared, internally in the LFE, to the eight ideal set
points versus time programmed into the LFE. The fuel tank thermocouple is
simultaneously connected to a temperature recorder as a permanent record of
the "Diurnal breathing loss test" temperature rise.
In the automatic mode, if the thermocouple signal is lagging behind the
temperature ramp, the LFE will increase the power output to the fuel tank heat
blanket. If the fuel temperature signal is ahead of the CFR temperature ramp,
power to the blanket is decreased or held at zero. At any time, the
temperature achiever can be put into manual mode to allow a technician to
apply or hold off power to the heat blanket. When the temperature achiever is
placed back in automatic the achiever will continue with the heat build
temperature set points, maintaining contiguity with the original start time.
Once the temperature achiever prototype was manufactured, VA&T began its
evaluation under actual test conditions. Heat builds on two different-sized
fuel tanks were performed to establish a volume range, on which the new
temperature achiever's automatic mode could be expected to satisfactorily
perform heat builds. A year's worth of VA&T test data were reviewed and
reduced to histograms of test vehicle fuel tank sizes to select the two test
volumes. The histograms revealed that using 13 gallons as low volume and 18
gallons as high volume would produce test data which would bracket 70 percent
of the heat builds performed in VA&T. 40 CFR 86.078-2 defines the "tank fuel
volume," used for the heat builds, as "determined by taking the manufacturer's
nominal tank(s) capacity and multiplying by 0.40." For these tests 5.2 and
7.2 gallons were used, corresponding to 13 and 18 gallons respectively. In
addition, the achievers had never approached using continual 100% power output
when EST had experimented with them. So we felt there would be no control
problems on large volume fuel tanks. This would leave only 7 percent of the
heat builds performed in VA&T (actual fuel volumes of less than 5.2 gallons)
which might require the heat builds run primarily in manual mode (Appendix
A-8).
Five diurnal breathing loss tests were performed on 5.2 gallons and five
on 7.2 gallons to allow the generation of confidence intervals representing
achiever operation on 93 percent of all vehicles tested in VA&T. All
temperature recordings were reduced to CFR temperature ramp target difference
from the actual temperature ramp value [Diff=T(actual)-T (CFR)] at each 5
minute interval from t=0 to t=60. The means, standard deviations, and 95
percent confidence intervals of the individual CFR temperature ramp targets'
differences from actual test temperature ramp values for the first set of
prototype evaluations by LPG are below:
-------
Table 1
NOVA (7.2 gal.)
Pinto (5.2 gal.)
Time
0
5
10
15
20
25
30
35
40
45
50
55
58
60
62
Diff
1.14
1.64
1.60
1.72
1.52
1.50
1.24
1.22
1.12
0.94
0.68
0.46
0.52
1.10
N
5
5
5
5
5
5
5
5
5
5
5
5
5
2
Std.Dev.
0.79
0.88
1.12
0.92
0.99
0.87
0.86
0.97
0.89
0.93
0.83
0.73
0.64
0.14
95%
(0.16,
(0.55,
(0.21,
(0.58,
(0.29,
(0.42,
(0.17,
(0.01,
(0.-01,
(-0.22
(-0.35
(-0.44
(-0.28
Cl
2.12)
2.73)
2.99)
2.86)
2.75)
2.58)
2.31)
2.43)
2.23)
,2.10)
,1.71)
,1.37)
,1.32)
Diff
1.22
1.42
1.12
1.43
1.37
1.25
1.00
0.65
1.15
0.78
0.53
0.70
0.33
0.25
N Std.
6 0.
6 0.
6 0.
6 0.
6 0.
6 0.
6 0.
6 0.
6 0.
6 0.
6 0.
6 0.
6 0.
4 0.
Dev.
44
72
82
84
72
84
52
82
71
52
59
81
60
66
95% Cl
(0.76,1.
(0.66,2.
(0.26,1.
(0.55,2.
(0.61,2.
(0.37,2.
(0.45,1.
(-0.21,1
(0.41,1.
(0.23,1.
(-0.09,1
(-0.15,1
(-0.30,0
(-0.80,1
68)
18)
98)
31)
13)
13)
55)
.51)
89)
33)
.15)
.55)
.96)
,30)
Both
Time
0
5
10
15
20
25
30
35
40
45
50
55
58
60
62
Diff
1.18
0.72
1.44
1.56
1.44
1.36
1.11
0.91
1.14
0.85
0.60
0.59
0.42
0.53
N
11
11
11
11
11
11
11
11
11
11
11
11
11
6
Std.Dev
0.59
1.52
0.93
0.85
0.81
0.82
0.67
0.90
0.75
0.69
0.68
0.74
0.60
0.68
95% Cl
(0.
(-0
(0.
(0.
(0.
(0.
(0.
(0.
(0.
(0.
(0.
(0.
(0.
(-0
78,1.58)
.30,1.74)
81,2.07)
99,2.13)
90,1.98)
80,1.91)
66,1.56)
30,1.52)
63,1.64)
39,1.31)
14,1.06)
09,1.09)
02,0.82)
.18,1.24)
The above data were generated on automatic control using various wattage
blankets to heat and type J thermocouples to measure fuel tank temperatures on
the different tests. Fuel tank temperatures were recorded on VA&T temperature
recorders which were calibrated independently of the temperature achiever.
All tests satisfied 40 CFR 86.133-78 requirements.
After review of the initial prototype data (Table 1)
raised:
two questions were
1. Can the microprocessor temperature control confidence intervals be
narrowed down by changing its internal control (tune) parameters?
2. Do the confidence intervals indicate that use of the temperature
achievers will result in temperature traces with positive temperature
rise bias from the CFR equation?
4
-------
The first question was answered by an LFE Corporation design engineer
(Appendix A-8). Under our test conditions, the one- to two-degree spread seen
in the confidence intervals in Table 1 is the best the microprocessors might
be expected to perform. The answer to the second question lies in how the
achievers will be used in actual testing. The heat builds will be monitored
by technicians. The technician will adjust the achievers manually to return
them to the CFR targets, if necessary. The technician control will ensure no
change in the stringency of the test, because historically all the "Diurnal
breathing loss tests" have been controlled by the test technicians (Appendix
A-12).
As a verification that the units could perform diurnal breathing loss
tests in automatic, exactly as specified in the CFR, new data were generated
using the same temperature achiever as before. The achiever and a recorder
were calibrated at the same time to ensure they agreed. The tests were
performed on automatic with the same recorder, thermocouple, heat blanket, and
a fuel volume of 6.6 gallons (mean gasoline volume of tests performed in
VAST). The mean, standard deviations and confidence intervals for each of the
5-minute intervals are presented below:
Table 2
Time
0
5
10
15
20
25
30
35
40
45
50
55
58
60
62
Diff
N
0.04
-0.04
0.00
-0.08
0.00
-0.04
-0.28
-0.60
-0.60
-0.72
-0.88
-1.04
-1.20
-1.32
5
5
5
5
5
5
5
5
5
5
5
5
5
5
Std.Dev.
0.30
0.26
0.37
0.50
0.49
0.33
0.39
0.40
0.47
0.36
0.30
0.26
0.32
0.23
95% Cl
(-0.38,0.46)
(-0.41,0.33)
(-0.53,0.53)
(-0.79,0.63)
(-0.70,0.70)
(-0.51,0.43)
(-0.83,0.27)
(-1.17,-0.03)
(-1.27,0.07)
(-1.24,-0.20)
(-1.31,-0.45)
(-1.41,-0.67)
(-1.65,-0.75)
(-1.64,-1.00
The manufacture and compliance testing of eleven LFE temperature achievers
(in addition to the prototype) took place from July 1987 through December
1987. Once an achiever satisfied the CFR Compliance Test Procedure (Appendix
A-10), it was placed in use. The compliance tests verified that each unit's
high temperature cutoff functioned and established that each achiever could
perform an automatic heat build on both a 5.2 gallon and a 7.2 gallon volume
of fuel. For acceptance, both fuel temperature traces had to be within ± 2°F
of the CFR ideal temperature rise ramp, all achievers met this criterion. The
summary statistics are presented below for all successful compliance tests.
-------
Table 3
(11 Temperature Achievers Tested)
Time Diff N Std.Dev. 95% Cl
0
5 1.2 24 0.91 (0.91,1.67)
10 1.38 24 0.77 (1.05,1.70)
15 1.04 24 0.75 (0.72,1.36)
20 0.67 24 0.92 (0.28,1.05)
25 0.58 24 0.97 (0.17,0.99)
30 0.46 24 0.83 (0.11,0.81)
35 0.50 24 0.98 (0.09,0.91)
40 0.54 " 24 0.93 (0.15,0.94)
45 0.63 24 0.82 (0.28,0.97)
50 0.33 24 0.64 (0.06,0.60)
55 0.33 24 0.82 (-0.01,0.68)
60 0.25 24 0.68 (-0.04,0.54)
Conclusions
1. When the temperature achievers are calibrated with the specific
recorders used for the heat builds and care is taken to match heat
blanket wattage to fuel volume, the performance of the temperature
achiever in automatic mode improves (Table 2).
2. The 95 percent confidence intervals of individual temperature
achiever CFR Compliance Tests indicate that the new temperature
achievers are capable of performing CFR heat builds in automatic mode
with a comparable repeatability of one degree on "Diurnal breathing
loss test" heat builds (per 40 CFR 86.133-78) performed on 13 and 18
gallon fuel tanks (Table 3). This performance is anticipated on 93
percent of the vehicles tested at MVEL (Appendix A-8)
Recommendations
1. Calibrate and maintain the temperature achievers in pairs with the
recorders with which they are used in conjunction.
2. Care should be taken to match heat blanket wattage to fuel volume.
(Technician judgement will be required until a study is made to
develop a specific guideline.)
3. Technicians should monitor the temperature achiever operation during
the diurnal breathing loss tests run on automatic.
4. Technicians should take special care with actual fuel volumes of 5.2
gallons or less. Diurnal breathing loss tests on these smaller
volumes may require being run entirely in manual mode.
0941e
-------
Appendix A
EQUIPMENT/PROCEDURE CHANGE NOTICE
1. ORIGINATOR /HL &
Carl M. Paulina \ v^\
4.
6.
7.
DIVISION CLEARANCE
2. PHONE EXT.
421
EPCN TO.
69
3. REVIEW
DUE DATE:
5< I!!!L.2F Q FED- REGISTER C
CHANGE: g EQUIPMENT L
DATE
09
ENTERED
/ 22/ 86
PAGE
1
OF
\
ENTER "FYP
]A/C
3 MSAPC
D FORM
PROCEDURE
a
OT;IER
REFERENCE DOCUMENTS (List Attachments, Forms, Procedures. FRfs, etc.)
40 CFR ft*. 107-78 40 C*R 86. 131-78, EPA TP 704A EPA TP 705B
DESCRIPTION OF CHANGE (Attach details, specifications, drawings, and Implen
entatlon
plan).
Description - This EPCN authorizes the use of a new model temperature achiever, controllec
by an LFE Corporation model 2010/2011 process microprocessor and an Athena model PC pro-
portional SCR. The heat blankets and thermocouples used for CFR gasoline tank heat
builds will remain unchanged.
Implementation - As each new unit is completed, it will be tested for safety and com-
pliance with the requirements of 40 CFR Section 86 subpart B. After a unit successfully
completes* the compliance test, it will be approved for use. Full implementation of the
12 new units is expected to be complete two months following EPCN approval.
Documentation - Prototype functional test data, system schematics, compliance test
procedures and results, and operational procedures will be retained in QC Group files.
8. PURPOSE OF CHANGE (Why 1s this change being proposed?)
Implementation of new electronic control system to replace obsolete units.
9. PROPOSED EFFECTIVITY
(Date. MY. etc.) A
1C(. 3, 1987
10. DURATION OR EXTENT OF USE
LH PERMANENT D TEMPORARY
11. AREAS OF MSAPC AFFECT
n HOT
E OTHER
n c & M
TP 7Q4A
BY THIS CHANGE
H INST. SERV.
D RTS HDWR.
ad TP 705B (see
U CHEM LAB.
D TEST VALID.
attached)
QC/QA
DATA BR.
ECTD
CSD
12. REVIEWS AND APPROVALS
REVIEWED BY
CONCURRENCE
COMMENTS
A..
James D. Carpenter, Ch
Facility Support Branch
$JYES D NO
John T. White, Ch
Testing Programs Branch
YES D NO
C. Don Paulaell, Ch
Engineering Staff, EOD
DNO
RECOMMENDED ACTION
THE
RECEIVED AM) OOOMNTED.
DIVISION RESPONSE (OC~\
CONDITIONAL APPROVAL
REQUEST TO REVIEW R
REDRAFT REQUIRED
RELEASED FOR IHPLEICNTATIOIt
THE PROVISIOB OF THIS
HOOT AimBBZED FOR
DATE
NSAK FOM 7.S
REVISE* 7/1/7S
Djsnuivnai: VICINAL
can i (Y«V
COPT 2 (HIM) - EPCH niTERIH LOS
Cart } (ffnk) . NCTAIKO BY
-------
L F£
ATHfNA f
X30/?.
T
TO
A-2
-------
Tewersture Controller Set Points
The following are the entries necessary to prosran an LFE proara§able controller to perfori FR gasoline
heat builds, The entries are Bade in conjunction with section III of LFE model 2010/2011 instalation and
operation manual, (955-239 revi A 3484)
Controller Response Entrs
"Set"point"o ~60"jF
Alan 1 4 JF
Alarm 2 -4 JF
PR Band 1 3 Z
Reset 1 0,10 R/H
Rate 1 . 0,77 H
Aux SP 13 JF
Aux BB 1,00 I
Ramp and Soak? YES
Set Point 0 60 JF
Time 1 7',31
Set Point 1 63 JF
TiM 2 7J30
Set Point 2 66 JF
TUe 3 7530
Set Point 3 6V JF
TiM 4 7',30
Set Point 4 72 JF
Ti«e 5 7',30
Set Point 5 75 JF
Tiie 6 7',30
Set Point 6 78 JF
Tiie 7 . 7',30
Set Point 7 81 JF
Tiie 8 7130
Set Point 8 84 JF
Cacles 1
Assured Soak ? NO
End of Tune
The above seauence ends the prosrstins necessara for the LFE to perfor* a Federal Reaister assoline
tank diurnal neat builds, Tliesy settings were used for all heat builds perforted to evaluate Tetperature
Achiever proto-type F,R, compliance UP to 3/10/87,
The following are the calibration entries, The units can be ordered with these entries,
PN DO 52 00 34 00
UNITS JF
TIME H!S
LO SPAN 60 JF
HI SPAN 86 JF
CAL COhPLETE
A-3
-------
LFE Corp. Temperature Achievers'
Operational Procedure
SET-UP:
1. If the display reads OPEN INPUT, plug in a type J thermocouple
(TC) to • TC jack on rear of unit. Allow a 3 to 5 minute warm-up
with a TC plugged in.
2. Connect the second TC jack on the rear of the temperature
achiever to the temperature recorder.
3. Press DISPLAY button (Item F figure Duntil the display
reads the same as figure 1.
4. If the temperature displayed on the achiever does not agree
with the temperature recorder within ±2*F after a 3-5 minute
warm-up, return the heat build cart to EST for calibration.
5. If a TC other than the test vehicle fuel tank TC (i.e. ambient)
is plugged into the jack at rear of achiever, switch it with the
fuel tank TC.
6. The green MAN light (Item B figure 1) should be flashing. [Achiever
is on hold. If not push START/STOP (Item I figure 1>]
7. Plug the vehicle heat blanket into the 120 volt AC jack on
back of the temperature achiever.
PRE-HEAT BUILD:
1. Push START/STOP (Item I figure 1) button [Flashing green
MAN light (Item B figure 1) will go out or remain on continually].
The temperature achiever has now begun a heat build cycle.
2. If the green MAN light (Item B figue 1) is not on continually,
push the AUTO/MANUAL button (Item E figure 1).
3. When the green MAN light (Item B figure 1) is on, the unit
is in a heat build cycle manual mode. The YES(t) and N0(40
buttons (Items G 4 H figure 1) control the amount of power to
the heat blanket. The rate of the gasoline temperature rise
will will be proportional to the percent power output. (Item
C figure 1) The fuel temperature rise preceding the heat
build should not exceed 1*F per minute.(TP705)
4. When the gasoline temperature approaches the point at
which the heat build will begin, press AUTO/MANUAL button
(Item E figure 1) and IMMEDIATELY press START/STOP (Item I
figure 1). The MAN light (Item B figure 1) should be
flashing. (Achiever is on hold)
AUTOMATIC HEAT BUILD CYCLE:
1. When ready to begin (60 t 2'F), push START/STOP (Item I
figure 1). Flashing green MAN light (Item B figure ') should
go out.(If not, see Pre-Heat Build #2) The achiever is now
performing a heat build.
2. Monitor the heat build temperature rise. If the gasoline
temperature is running behind or ahead of target, use
AUTO/MANUAL button (Item E figure 1) and set the desired
power output. You can return to the automatic mode whenever
you wish by pressing AUTO/MANUAL buttondtem B figure 1), the
achiever should resume the proper heat build ramp. The test
may be finished in manual mode, if desired.
3. The temperature achiever will automatically shut-off at
the end of the 60 minute heat build cycle.(Manual or
Automatic Modes) If you wish to continue applying heat see
PRE-HEAT BUILD.
DO NOT LEAVE TEMPERATURE ACHIEVER UNATTENDED
IN EITHER MANUAL OR AUTOMATIC MODE
A-4
-------
£»r, LJ.<7y
FIGURE 1
DESCRIPTION
60 JF
B ) HAN
OUT1 I
Z OF OUTPUT
AUTO/MANUAL
DISPLAY
©
©
©
©
GJ N0(i)
H) YES(t>
START/STOP
©
FUNCTION
DISPLAYS FUEL TEMPERATURE(60* FiTYPE J THERMOCOUPLE)
DISPLAYS OPERATIONAL MODE -
BLINKING: ON HOLD
OFF ! HEAT BUIiD CYCLE (AUTOMATIC)
ON ', HE«T BUILD CYCLE (MANUAL)
DISPLAYS PERCENTAGE POWER OUTPUT TU BLANKET
LAMP BRIGHTNESS INCREASES HUH POWER
OUTPUT TO HEAT BLANKET
PRESS TO SWITCH UNIT BETWEEN AUTOMATIC
AND MANUAL MtlUES (MES NOT IHTERUPT
60 KIN. HEAT BUILDtYCLE)
PRESS TO CHANGE PAKAHETERS DISPLAYED IN
READOUT, (PRESS UNTlL DISPLAY IS
SAME AS FIGURE 1)
PRESS TO DECREASE POWER OUTPUT TO HEAT BLANKEf,
(MANUAL MODE ONLY)
PRESS TO INCREASE POWER OUTPUT TO HEAT BLANKET.
(MANUAL MODE ONLY)
PRESS TO BEGIN OR END HEAT BUILD CYCLE
(RESETS TO TIKE*0 ON STOP)
A-5
-------
/DELTA TEMP. FROM TARGETS
TlMEfmin.i
5
10
15
20
25
30
35
40
45
50
55
58
60
62
TARGET TEMP.
RISE
2.0
4.0
6.0
8.0
10.0
12.0
14.0
16.0
18.0
20.0
22.0
23.2
24.0
24.8
CHECKOUT
LIMITS
(-2.0,-f2.0)
(-2.0.+2.0)
(-2.0.+2.0)
(-2.0.+2.0)
(-2.0.+2.0)
(-2.0.+2.0)
(-2.0.+2.0)
(-2.0.+2.0)
(-2.0.+2.0)
(-2.0.+2.0)
(-2.0.+2.0)
(-2.0.+2.0)
(-2.0.+2.0)
(-2.0.+2.0)
AUTOMATIC VOID
REGULATORY LIMITS
(-3.0,+3.0)
(-3.0.+3.0)
(-3.0.+3.0)
(-3.0.+3.0)
(-3.0.+3.0)
(-3.0.+3.0)
(-3.0.+3.0)
(-3.0.+3.0)
(-3.0.-I-3.0)
(-3.0.+3.0)
(-3.0.+3.0)
(-3.0.+3.0)
(-3.0.+3.0)
(-3.0.+3.0)
VALID TEST END
LIMITS (ANY OF sa.
60 OR 62 MIN INTFRX/ALSJ
(-0.2.+1.8)
(-1.0.+1.0)
(•T.8,+0.2)
A-6
-------
I I I i I.!
i : I M :
I ! ! i f J
hi.!J
''I-!! i-i i i
-------
3/5/87
Additional Information/Clarification
1. Set-up parameters used in proto-type. - Attached (supplied
by EST)
2. Does Q.C. feel that data from 5.2 and 7.2 gallon nominal tank
volume heat builds indicate an operational offset from 0
target that should necessarily be corrected by changing
microprcessor tune parameters?
Answer-No. The initial eleven tests were performed with no control
on heat blanket size, thermocouple type
(intank,stick-on,weighted,etc), temperature recorder
.agreement with temperature achiever proto-type, or technician
familiarity with operation of the units(no attention given to
pre-heat build temp, rise and tests performed on full auto-
matic). The tests were performed over approximately two
months with no calibration checks on the-recorders or
proto-type. Q. C. and Mark Alarie (engineer LFE) agree with
Project Engineer that the data indicates an ability of the
Temperature Achiever proto-type to control temperatures
within a 2-2.5 degree F range, Fed. Reg. allows 6 degrees- F.
The temperature achiever proto-type(set-up parameters same as
initial 11 tests) had its temperature read-out
re-calibrated(it was 1-2 degrees high). A temperature
recorder was calibrated at the same time and all second set
tests were performed with the same recorder. All 5 new heat
builds were performed with an in tank weighted TC, 6.4
gallons of gasoline(approx. mean of all nominal fuel tank
volumes over previous year), 600 watt heat blanket,and all
automatic operation.(No technician overides were allowed
although it will probably be common in practice.) The summary
of the second set of tests is attached. Mark Alarie(engineer
for LFE Corp.) went on to say that the units could not be set
up to function exactly the same with heat blankets that range
from 600 to 2000 watts and varying tank sizes. In Mark's
opinion all the tests results sound as if the proto-type is
operating about as well as can be expected and "fine tuning"
the units is time and labor intensive.
Conclusion : boTa does not indicate that all LFEs will have a positive
temperature offset from heat build ramp target temps with the
set-up parameters established by EST(temp. achiever
proto-type developers)
Suggested Areas of Responsibility:
1.Calibration(EST)
2.Blanket to volume sizing(VAT)
3. Other vehicles tried?
Answer : Histograms of 2046 tests in the previous year indicate that
only 7% of the vehicles tested in VAT would have nominal tank
volumes(40% full) of less than 5.2 gallons. In all the tests
performed with the proto-type the unit hasn't even approach
A-8
-------
maximum power to the blanket over the entire hour heat build.
I feel we should have no problems controlling heat builds on
higher volumes of gas than those used. If the 7% of test
vehicles which would have nominal volumes smaller than the
5.2 gallon tests have too small of thermal capacities for
this proto- type combined with our present heat blanket
stock, technician overide and/or stocking smaller power heat
blankets should minimize problems in this area.
4. Branch Chief needs an explanation of 58 to 62 minute limits.
Answer : If the temperture rise is within any of the acceptance
intervals written for 58, 60,or 62 minutes, the heat build
can be stopped and-the test is valid (if the 3 degree limit
has not been violated.)
5. Why not use ATA ramp for heating fuel to starting point?
Answer : Two reasons -
1. VAT technicians require the ability to coax two vehicles
to their starting temps at different rates so that vehicles
can be started at the same time.
2. Temperature achiever operation will cause 100% power •
output with present set-up, resulting in overdriving the fuel
temperature at test start. Fuel dispensing temperature
variability prevent programming a cycle for pre-heat build
ramp.
6. Should it stop @ 60 minutes - may want 62 in case its comming
up slow?
Answer : Maybe. Lets let VAT & EST decide. It can easily be
incorporated. I don't see any reason to hold up manufacturing
the units for VAT, inorder to do additional Resting.
A-9
-------
Automatic Temperature Achiever CFR Compliance Test Procedure
Safety Temperature and Automatic/Manual Override Tests :
Place thermocouple and -a thermometer into a beaker of
water at less than 60°F. Plug the thermocouple into back
of temperature achiever. Plug one hundred ten volt AC
lamp into power output plug on back of temperature
achiever. Start automatic heat build cycle. One hundred
ten volt lamp should light with power output. Push
AUTO/MANUAL button. Green MAN light (on front of LFE)
should stay on. Push NO (4») button on temperature achiever
front until one hundred ten volt lamp goes out and power
output reading on front of temperature achiever goes to
0%. Push YES (f) button until power output goes to 75%.
Supply a millivoltage equivalent to 90° i 1 ° F to the
thermocouple jack on the rear of the temperature achiever. The
one hundred ten volt and front indicator lamps should go out.
2. Set up temperature achiever/heat blanket with a vehicle
containing 7.2 gallons of gasoline.
3. Perform heat build. Temperature trace must satisfy the
following conditions:
F = T + 0.4 t
where:
F = fuel temperature, °F
t = time since start of test in minutes
T = 60 + 2°F (initial fuel temperature)
After 60 +.2 minutes of heating, the fuel temperature rise
shall be 24Q±. 1°F. Save temperature trace with temperature
achiever unit #, test date, gasoline amount, chart speed,
and heat blanket power rating.
4. Perform steps 2-3 with a vehicle containing 5.2 gallons
of gasoline.
A-10
-------
5. Test Acceptance Criteria :
A. Achiever stops automatic cycle at 60 minutes.
B. Based on a 60°F start temperature, the temperature
trace will meet the following criteria ± 2°F,in the
automatic mode.
Automatic Temperature Achiever
temperature vs time
Minutes Fuel Temperature (°F)
0 60
5 62
10 64
15 66
20 68
25 70
30 72
35 74
40 76
45 78
50 80
55 82
At 60 i 2 minutes the fuel temperature rise will be 24 ± 1 F,
No round offs will be acceptable.
C. Must be able to perform step 1 completely, (manual
power increase and decrease, 90*F power output shut
off)
If temperature achiever fails to meet the above criteria, return to
EST for calibration until unit successfully passes all criteria.
A-ll
-------
LFE Temperature Achiever Theoretical Rationale
On Need for Comparative Data
I feel that we should not run comparitive testing between the
new temperature achievers and the old to determine if the new
achievers will affect gasoline vehicle evaporative emissions from
historical because:
1. The fuel tanks will continue to be heated by the same heat same
heat blankets as previously.
2. Fuel tank temperatures will be measured by the same thermocouples.
3. The thermocouple, recorder, temperature achiever, heat blanket/fuel
volume match ups all dictate the performance of the temperature
achievers fuel temperature heat build on automatic.
Conclusion: It is not possible to determine a typical configuration
to compare.
4. Heat builds will always be performed under technician supervision.
The technicians were the controling influence on heat builds in the
past, and will continue to be with the new achievers.
Conclusion: Fully automatic heat build comparison to prevous tests
would not be valid and technician supervision of the
heat builds will ensure no change in the test stringency.
5. No real baseline of comparison exists. It would require a data search
through analog temperature traces to establish what our historical
temperature rise confidence intervals are. Do we want to spend
considerable resources to establish historical test variability on a
test that is primarily technician controlled ? Since the new achievers
have technician overide capability, there isn't any reason to assume
there will be a difference in the heat build temperature rise values
from historical.
A-12
-------
TEST#1 STATISTICS
NOVA
t>m*
0
5
10
15
20
25
30
35
40
45
50
55
58
60
62
A<*t/A
1.14
164
1.60
1.72
1.52
1.50
1.24
1.22
1.12
0.94
068
0.46
0.52
1.10
M
5
5
5
5
5
5
5
5
5
5
5
5
5
2
a
0.79
0.88
1.12
0.92
0.99
0.87
0.86
0.97
0.89
093
0.83
0.73
064
0.14
ncox /M y
;Jj/» VJ Aa»/n
(0.16.2.12)
(0.55,2.73)
(0.21,299)
(0.58,286)
(0.29,2.75)
(0.42,2.58)
(0.17.2.31)
.22
.42
.12
.43
.37
.25
.00
(0.01,2.43) 065
(0.01,2.23) 1.15
(-0.22.2.10) 0.78
(-0.35,1.71) 0.53
(-0.44.1.37) 070
(-0.28,1.32) 0.33
0.25
N
6
6
6
6
6
6
6
6
6
6
6
6
6
4
PINTO
a
0.44
072
082
0.84
0.72
084
0.52
082
071
052
059
0.81
060
0.66
9$% C\
(076.1.68)
(066.2.18)
(0.26.1.98)
(055.2.31)
(0.61.2.13)
(0.37.2.13)
(0.45.1.55)
f-0.21,1.51)
(041.189)
(023.1.33)
(-0.09,1.15)
(-0.15,1.55)
(-030,096)
(-080,1.30)
•^ave
1.18
072
.44
.56
.44
.36
.11
0.91
1.14
0.85
060
0.59
0.42
0.53
N
11
11
11
11
11
11
11
11
II
11
11
11
11
6
TOTAL
a
0.59
1.52
0.93
085
0.81
0.82
0.67
0.90
0.75
0.69
0.68
0.74
0.60
0.68
95% Cl
(0.78.1.58)
(-0.30.1.74
(081.2.07)
(0.99.2.13)
(0.90,1.98)
(0.80.191)
(0.66.1.56)
(0.30,152]
(0.63.164;
(0.39.1.31;
(0.14.1.06;
(0.09.1.09
(0.02,0.32
(-0.18,1.2"
A-13
-------
TEMPERATURE ACHIEVER EVALUATION
TEST SET #1
(Random temperature achiever, temp, recorder, thermocouple, heat blanket,
and fuel tank matchups)
AT= DEVIATION FROM DESIRED RAMP. °F
0
5
10
15
20
25
30
35 .
40
45
50
55
53
60
62
0.0
1.3
1.4
1.0
1.2
1.0
0.9
0.8
0.5
0.6
0.7
0.2
0.1
0.2
^
0.0
0.0
0.4
0.2
0.8
0.2
0.4
0.0
0.0
0.0
-0.4
-0.4
-0.6
0.0
a ,
0.0
1.0
1.8
1.8
1.8
1.8
1.8
1.4
1.4
1.0
0.8
0.6
0.6
0.0
4
0.0
2.2
2.3
3.2
3.0
2.8
2.6
2.2
2.4
2.2
2.0
1.6
1.2
1.4
1.2
5
0.0
1.2
2.0
2.0
2.2
2.0
2.0
1.8
1.3
T.8
1.6
1.4
1.0
1.0
1.0
S
0.0'
1.2
0.1
-0.2
0.0
0.3
0.2
0.2
0.2
0.3
0.1
0.0
•0.2
•0.4
7
0.0
0.5
1.4
1.2
1.0
0.7
0.5
1.0
0.3
0.3
0.4
0.0
0.0
0.4
a •
0.0
1.8
2.0
2.0 .
2.2
2.0
2.0
1.6
1.8
1.3
1.8
1.8
1.2
1.4 •
1.2
_3L-
0.0
1.4
2.0
2.0
2.2
2:0
2.0
1.4
1.4
1.4
0.8
0.8
0.6
0.4
0.2
— L0_
0.0
1.0
1.2
1.2
1.4
1.4
0.3
0.6
1.0
1.2
0.3
0.6
0.2
0.2
•0.2
„ 11
0.0
1.4
1.8
1.8
1.8
1.8
2.0
1.2
1.0
1.9
1.0
0.4
0.6
0.0
•0.2
1 NOVA Tank Vol 7 2 Gal. 6 PINTO Tank Vol. 5.2 Gal.
Large Blanket Small Strip Blanket
No Thermocouple Indicated No Thermocouple Indicated
7/23/86 8/1/88
2 NOVA Tank Vol. 7.2 Gal.
Crank Strip Blanket
In-Tank Thermocouple
8/28/88
3 NOVA Tank Vol. 7.2 Gal.
Large Blanket
Magnetic Thermocouple
No Date Indicated
4 NOVA Tank Vol. 7.2 Gal.
Medium Blanket
In-Tank Thermocouple
9/12/86
5 NOVA Tank Vol. 7.2 Gal.
Medium Blanket
In-Tank Thermocouple
9/12/86
7 piNTO TanK Vo1- 5 2 Gal-
Medium Strip Blanket
No Thermocouple Indicated
3/13/86
8 PINTO Tank Vol. 5.2 Gal.
Strip Blanket
In-Tank Thermocouple
9/17/86
9 PINTO Tank Vol. S.2 Gal.
Strip Blanket
In-Tank Thermocouple
9/17/86
10 PINTO Tank Vol. 5.2 Gal.
Strip Blanket
In-Tank Thermocouple
9/17/86
A-14
PINTO Tank Vol. 5.2 Gal.
Strip Blanket
In-Tank Thermocouple
9/17/86
-------
TEST #2 STATISTICS
tima
0
5
10
15
20
25
30
35
40
45
50
55
53
60
62
x
0.04
-0.04
0.00
-0.08
0.00
-0.04
-0.28
-0.60
-0.60
-0.72
-0.88
-1.04
-1.20
-1.32
N
5
5
5
5
5
5
5
5
5
5
5
5
5
5
NOVA
CT
0.30
0.26
0.37
0.50
0.49
0.33
0.39
0.40
0.47
0.36
0.30
0.26
0.32
0.23
95% C.I.
(-0.38, 0.46)
(-0.41, 0.33)
(-0.53, 0.53)
(-0.79, 0.63)
(-0.70, 0.70)
(-0.51, 0.43)
(-0.83, 0.27)
(-1.1 7, -0.03)
(-1.27, 0.07)
(-1.24, -0.20)
(-1.31, -0.45)
(-1.41, -0.67)
(-1.65, -0.75)
(-1.64, -1.00)
A-15
-------
TEMPERATURE ACHIEVER EVALUATION
TEST SET#2
(Same temperature achiever, temperature recorder, thermocouple, heat
blanket and fuel tank volume on all tests. Temperature recorde^and
achiever temperature values calibrated to exact agreement.)
AT = DEVIATION FROM DESIRED RAMP. °F
jicofl^^^
5
**
10
15
20
25
30
35
40
45
50
55
53
60
62
0.0
0.2
0.2
0.2
0.2
0.0
-0.2
-0.4
-0.8
-0.8
-0.6
•1.0
-1.0
•1.4
•1.4
2
0.0
-0.4
-0.4
-0.4
•0.8
•0.8
-0.4
-0.3
-1.0
-1.0
•1.2
•1.2
•1.2
•1.6
-1.6
3
0.0
0.4
0.2
0.2
0.2
0.4
0.4
0.0
0.0
0.2
-0.2
-0.4
-0.6
-0.8
•1.0
4
0.0
0.0
0.0
0.4
0.4
0.4
0.2
0.2
-0.4
•0.6
•0.3
•0.3
-1.2
-1.0
-1.2
5
0.0
0.0
-0.2
•0.4
•0.4
0.0
•0.2
•0.4
-0.8
•0.8
•0.8
-1.0
-1.2
•1.2
-1.4
WHITE NOVA Tank Vol. 6.4 Gal.
Heat Blanket MS-8 600 Wans
No Termocoupla Indicated
2-24-87
WHITE NOVA Tank Vol. 6.4 Gal.
Heat Blanket MS-8 600 Wans
No Termocouple Indicated
2-25-87
WHITE NOVA Tank Vol. 8.4 Gal.
Heat Blanket MS-8 600 Wans
No Termocouple Indicated
2-25-87
WHITE NOVA Tank Vol. 8.4 Gal.
Heat Blanket MS-8 600 Wans
No Termocouple Indicated
2-25-87
WHITE NOVA Tank Vol. 6.4 Gal.
Heat Blanket MS-3 600 Wans
No Termocouple Indicated
2-25-87
A-16
-------
Appendix B
Quan.
1
LFE Temperature Achiever
Bill of Materials
1/27/88
Part or Manufacturer Description/Part No.
Bud Cabinet
Hubbell
Buss
Littlefuse
Magnecraft
Sylvania
Light
Dialight
Athena
Athena
LFE
Thermo-Electric
Showcase: finish royal
blue textured with white
frame/BB-1804-RB
3-wire grounding flanged
receptacle/5256
Fuse holder/Newark
N0.81F2154
Fuse/KLK-30
Relay/W199AX-YSPDT
120 VAC
Lamp/7 watt 125 v c7 7c7
Amber lens/ Newark No.:
25F1578
Indicator light base/
Newark No. :45F606
Alarm circuit controller,
overtemperature/
86AB-03F
Power Pack/PC-24-35-0-v
Micro-Processor/Model:
2010 PUP, PN DO 5200
3400
T.C. Jacks
Part/41806-JX Type J
-------
TRW Cinch Connectors/6-#141
Belden Wire 9918 BLK, 9918 White,
8916 BIK, 8916 white
Voltrex Cable Clamps 5/16
DiaVNewark No. 32N1272
------- |