ASTM D1740-96
(Test Method)Standard Test Method for Luminometer Numbers of Aviation Turbine Fuels
Standard Test Method for Luminometer Numbers of Aviation Turbine Fuels
SCOPE
1.1 This test method² covers the measurement of the flame radiation characteristics of aviation turbine fuels and other similar distillate fuels expressed in terms of luminometer numbers. There is good correlation between smoke point (Test Method D 1322) and luminometer number which is presented in Appendix XI.²
1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For specific precautionary statements, see 7.1, 7.2, 8.1, 8.2 and Annex A1.1.
Note 1 - It is the intent of Subcommittee J to ballot to withdraw this test method when due for reapproval in 2006, because of very limited and declining use to determine compliance with aviation turbine fuel specifications.
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn. Contact ASTM
International (www.astm.org) for the latest information.
An American National Standard
Designation:D1740–96
Standard Test Method for
Luminometer Numbers of Aviation Turbine Fuels
This standard is issued under the fixed designation D1740; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
This test method has been adopted for use by government agencies to replace Method 2108 of Federal Test Method Standard No. 791b.
1. Scope obtaining a curve of flame radiation, as measured by an optical
2 filter and photo cell unit against the temperature rise across the
1.1 This test method covers the measurement of the flame
burner measured by a thermocouple placed just above the
radiation characteristics of aviation turbine fuels and other
flame.This temperature rise is compared with that obtained on
similar distillate fuels expressed in terms of luminometer
a pair of reference fuels at a constant radiation level.To ensure
numbers. There is good correlation between smoke point (Test
that the constant rating level is the same in all units, it is
Method D1322) and luminometer number which is presented
defined as the smoke point of tetralin. Luminometer number is
in Appendix X1.
calculated from the difference in temperature rise between the
1.2 This standard does not purport to address all of the
test fuel and the temperature rise for tetralin divided by the
safety concerns, if any, associated with its use. It is the
difference in temperature rise for isooctane and tetralin.
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
5. Significance and Use
bility of regulatory limitations prior to use. For specific
5.1 This test method provides an indication of the relative
precautionarystatements,see7.1,7.2,8.1,8.2andAnnexA1.1.
radiation emitted by the combustion products of gas turbine
2. Referenced Documents fuels from a diffusion flame. The radiation level, expressed as
luminometer number, is related to the hydrocarbon type com-
2.1 ASTM Standards:
position of such fuels.Ahigh luminometer number indicates a
D1322 Test Method for Smoke Point of Aviation Turbine
fuel of low radiation characteristics.
Fuels
5.2 The luminometer number (and the smoke point with
D1655 Specification for Aviation Turbine Fuels
which it can be correlated) is qualitatively related to the
D2880 Specification for Gas Turbine Fuel Oils
potential radiant heat transfer from the combustion products of
3. Terminology the fuel. Because radiant heat transfer exerts a strong influence
on the metal temperature of combustor liners and other hot
3.1 Definitions of Terms Specific to This Standard:
sectionpartsofgasturbines,theluminometernumberprovides
3.1.1 luminometer number—a measure of flame tempera-
a basis for correlation of fuel characteristics with the life of
ture at a fixed flame radiation in the green-yellow band of the
these components.
visible spectrum.
3.1.1.1 Discussion—It can be correlated with combustion
6. Apparatus
characteristics of fuels for use in current commercial aviation
6.1 ASTM-CRC Luminometer, shown schematically in
turbine engines.
Fig. 1, consisting of three main parts:
4. Summary of Test Method 6.1.1 A small wick-type lamp in which the sample is
burned,
4.1 The luminometer number of a fuel is determined by
6.1.2 An optical filter and photocell circuit which indicates
burning the fuel in the ASTM-CRC Luminometer lamp and
the intensity of flame radiation in the range from 4800 to 7000
˚
A and
6.1.3 Asystem to measure the lamp temperature rise above
This test method is under the jurisdiction of ASTM Committee D-2 on
Petroleum Products and Lubricants and is the direct responsibility of Subcommittee
ambient. Luminometers through serial No. 377 include a dual
D02.J on Aviation Fuels.
thermocouple circuit and potentiometer, while later instru-
Current edition approved April 10, 1996. Published June 1996. Originally
ments include a digital output unit.
published as D1740 – 60T. Last previous edition D1740–91.
Thistestmethodwasdevelopedonthebasisofcooperativeworkcarriedoutby
the Coordinating Research Council and published in CRC Report “Evaluation of
CRC Luminometer” (CRC Project No. CA-16-58). June 1959. The ASTM-CRC Luminometer, made by ERDCO Engineering Corp., 721
Annual Book of ASTM Standards, Vol 05.01. Custer Ave., P. O. Box 1310, Evanston, IL 60204 has been used to develop the
Annual Book of ASTM Standards, Vol 05.02. precision of Test Method D1740.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn. Contact ASTM
International (www.astm.org) for the latest information.
D1740–96
FIG. 1 Diagram of ASTM-CRC Luminometer
6.2 Lamp Wicks—Standard ASTM smoke point lamp 7.4 Toluene, reagent grade,(Warning—Flammable. See
wicks are used in the ASTM-CRC luminometer lamp. A1.4.)
7.5 Methanol, reagent grade,(Warning—Flammable. See
7. Reference Materials and Reagent
A1.5.)
7.1 Isooctane (Warning—Extremely flammable. Harmful
if inhaled. Vapors may cause flash fire. See A1.1.) (2,2,4-
8. Preparation of Apparatus
trimethyl pentane) ASTM reference grade conforming to the
8.1 Cleaning the Lamp—Before each test, clean the top and
following specifications:
inside of the wick guide (in the lamp body) with acetone
Density at 20C, g/mL 0.69175 to 0.69205
20 C (Danger—Extremely flammable. Vapors may cause flash fire.
Refractive index, N 1.39135 to 1.39165
d
Freezing point, °C −107.52 See A1.3.) using a small test tube brush. Protect the optical
Distillation:
filter with a tissue during cleaning. Check the filter for spots
Temperature at which 50 % is recovered, °C 99.20 to 99.30
after cleaning and if the filter is found to be spotty, clean in
7.2 Tetralin,(Warning—Combustible. Vapor harmful. In
place with lens tissue. If necessary, the filter can be removed
animal tests, repeated oral or inhalation exposures caused liver
for cleaning by first removing the lamp and then unscrewing
and kidney damage and the formation of eye cataracts. See
thefilterretainingring.Followingthereplacementofthelamp,
A1.2.) conforming to the following specifications:
reference fuel checks should be made.
Specific gravity 25/25 C 0.969 to 0.97
8.2 Wicks and Sample Holders—Only new wicks shall be
20 C
Refractive index, N 1.5396 to 1.5410
d
used. Extract all wicks for at least 25 cycles in a reflux
Distillation, from first drop to dry, °C 206 to 208
condenser with an equal volume mixture of toluene
7.3 Acetone, cp.(Warning—Flammable. See A1.3.)
(Warning—Flammable. Vapor harmful. See A1.4.) and anhy-
drous methanol (Note 1). (Warning—Flammable. Vapor
harmful. May be fatal or cause blindness if swallowed or
Standard smoke point wicks are obtainable through Erdco Engineering Corp.,
inhaled. Cannot be made nonpoisonous. See A1.5.) Allow the
721 Custer Ave., PO Box 1310, Evanston, IL 60204 and Koehler Instrument Co.,
1579 Sycamore Ave., Bohemia, NY 11716. wickstodrypartiallyfor5min,thenplacetheminanovenand
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn. Contact ASTM
International (www.astm.org) for the latest information.
D1740–96
dry for ⁄2 h at 100 to 110°C. Store in a dessicator until used. 8.4.2 Temperature Indicator (Serial No. 378 and
Thoroughly wash the sample holder in acetone and dry (Note higher)—Be sure the ambient air thermocouple is in its
2).Then insert a dry wick in the wick tube of the clean sample operatingposition(pulledtotherighttowardthelamp)andthe
holder.Apieceofthinwirehookedthroughtheendofthewick stack thermocouple is connected.The output switch must be in
will allow the wick to be pulled through the tube without the“OFF”position.Placethepowerswitchinthe“F”ahrenheit
twisting. Use a clean razor blade or other sharp instrument to position. No additional adjustment is required. Return power
cut off the wick flush with the top of the wick tube (Note 3). switch to the “OFF” position between tests to conserve
Raise the wick by twisting the lower part until the end of the batteries. (Note 5.)
wick protrudes. Then, pull the wick up and remove any twists 8.4.2.1 Four type 1.2 AHR SC Size rechargeable batteries
inthewickbyrotatingtheendsofthewick.Alsopullthewick are used to supply power for the unit. To recharge the battery
down until the top of the wick is ⁄4 in. (6.4 mm) above the pack, insert the battery charger plug into the “RECHARGE”
tube.Trimanyfrayedendsfromthetopofthewick.Ifthewick jack located on the front panel. Use the 115 volt charger only
has not been cut square, recut and position as outlined above. on a 115 volt line (Note 5).
(Note 4.)
NOTE 5—Formaximumbatterylife,itisrecommendedthattheunit be
charged only when the discharged battery indication (display indicates
NOTE 1—If extraction facilities are not available, request supplier to
HELP) is observed. Do not charge for periods longer than 18 h. Charge
supply wicks that have been extracted.
unit before initial use.
NOTE 2—If either fuel or acetone vapors are not removed from the
sample holder during the cleaning and drying operations, erroneous Display Symbols
HI— temperature over range
ratings can be obtained.
Help— batteries discharged
NOTE 3—Some razor blades have a protective chemical coating which
F— fahrenheit
should be removed with a solvent.
NOTE 4—An alternative method of preparing a wick free of twists and 8.4.3 Digital Temperature Indicator (Serial No. 410 and
frayedendsutilizesaWickTrimmerAssembly. Thewicktrimmerholder
Higher)—Be sure the ambient air thermocouple is in its
is inserted over the top of the wick tube and the long-nosed triceps are
operating position (fully extended to the lamp) and the stack
inserted through the tube and holder. The wick is grasped and carefully
thermocouple is connected. Turn unit on by pressing the
pulled through the tube without twisting.Anew clean sharp razor is used
On/Off position on front key pad. Input temperature will be
tocutthewickatthefaceoftheholderandremovewispsandfrayedends.
displayed.
When the holder is removed, the wick will be at the correct height in the
8.4.3.1 Battery is a standard 9 V to supply power for the
tube. The tube is then inserted into the candle and screwed home. The
candle is inserted into the lamp. unit.
8.5 Luminometer Meter —Turn the switch located below
8.3 The flame axis of the ASTM-CRC Luminometer lamp
the right hand side of the luminometer meter to the OFF
must be vertical for proper operation. Adjustable cabinet
position. Adjust the meter to “0” by rotating the meter arm
vibrationmountsareprovidedforthispurpose.Adjustmentcan
pivot screw on the lower front center of the meter. Then turn
be checked by a small level positioned on the large flame
the switch to ZERO and turn the zeroing adjustment control
height adjusting ring. The level of the lamp should be checked
located below the left-hand side of the meter until the meter
in both the front to rear plane and the side to side plane. If at
arm rests at “0”. To facilitate zeroing use the coarse and a fine
anytimethepositionofthecabinetorthelampisdisturbed,the
zero adjustment. Next turn the switch toA,A,B , and B to
1 2 1 2
lamp level must be checked. If the position of the stack
check the battery voltage. If on each switch position the meter
thermocouple is disturbed or the thermocouple replaced, the
rests above the appropriate mark on the meter scale, the
thermocoupleshouldbepositionedwiththejunctionexactlyon
batteries are satisfactory and the unit is ready for use. If the
the lamp centerline. The bottom of the thermocouple shield
batteries are under strength, replace them. When replacing the
should be exactly 1 in. (25.4 mm) above the wick guide.
“B” batteries also replace the photocell batteries located inside
Suitable gages for this purpose are available from the manu-
the photocell box.
facturer.
8.4 Temperature Measurement:
9. Procedure
8.4.1 Potentiometer (Serial No. 377 and earlier)—Be sure
9.1 Introduce20mLoftetralinatroomtemperatureintothe
theambientairthermocoupleisinitsoperatingposition(pulled
cleandrysampleholder.Placethewicktubeintothetopofthe
to the right toward the lamp) and the stack thermocouple is
sample holder and screw tight. Run a small wooden applicator
connected. Turn the right switch of the potentiometer to TEST
stick into the air vent hole in the bottom of the holder to free
position; also turn the lower left switch to ZERO position and
the vent of fuel. When the fuel rises to the top of the wick,
holdwhileadjustingtheuppercenterknobuntilthegalvanom-
placethesampleholderinthelampandlightit(Note6).Ifany
eter pointer rests at “0” (mechanical zero). Turn the lower left
soot builds upon the thermocouple shield, put out the flame,
switchtoSTDandholdwhileadjustingthebatteryknob(upper
clean the shield, lower the sample holder slightly and relight.
left) until the galvanometer rests at“ 0” (electrical zero). If the
Through the observation peep hole in the center of the lamp
meter will not standardize, replace the internal potentiometer
door note that the flame is burning free of smoke (Note 7). Let
battery.
the tetralin burn at this level for 15 min to warm up the
apparatus.
Wick Trimmer Assembly, ERDCO Part No. 2LA-5520.
8 9
Battery Pack, ERDCO Part No. 2LA-14229. ERDCO Part No. HCS-7962.
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn. Contact ASTM
International (www.astm.org) for the latest information.
D1740–96
NOTE 6—Caution:Do not allow the flame to come closer than ⁄8 in.
9.4 Run two samples of ASTM reference fuel grade iso
(3.2 mm) from the thermocouple or the potentiometer (digital indicator-
octane as described in 9.1-9.3, but obtain four data points, two
Serial Nos. 378 or higher) to read 1000°F (538°C) or higher.
below and two above the rating level established with tetralin
NOTE 7—All ASTM-CRC Luminometers have been adjusted by the
for the instrument. (The four data points should be uniformly
manufacturer to read 45 to 55 at the smoke point of tetralin. If the unit is
separated by approximately 10 luminosity units.) One of the
outside this range, adjust the internal resistor located between the two
samples should be run before running the unknown test fuel;
amplifiertubes(removetherearcoveroftheunit)untilameterreadingof
the other sample should be run after running the test fuel. Plot
45 is obtained.
two curves, and at t
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