ASTM D3240-91(1996)

NOTICE: This standard has either been superseded and replaced by a new version or
withdrawn.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.
Designation: D 3240 – 91 (Reapproved 1996) An American National Standard
AMERICAN SOCIETY FOR TESTING AND MATERIALS
100 Barr Harbor Dr., West Conshohocken, PA 19428
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
Standard Test Method for
Undissolved Water In Aviation Turbine Fuels
This standard is issued under the fixed designation D 3240; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope 5. Apparatus
1.1 This test method covers the measurement of undissolved 5.1 Test Pad Rater—A device for comparing the fluores-
water in aviation turbine fuels in flowing fuel streams without cence of the test pad to a known standard, while both are
exposing the fuel sample to the atmosphere or to a sample illuminated by the same source of UV light, shall be used. The
container. The usual range of test readings covers from 1 to 60 amount of UV light striking the standard shall be modulated
ppm of free water. This test method does not detect water until the total fluorescence of the test pad and the standard are
dissolved in the fuel, and thus test results for comparable fuel equal; this shall be determined using a photocellbridge circuit
streams can vary with fuel temperature and the degree of water null indicator. The light modulating device for controlling the
solubility in the fuel. UV light striking the standard shall provide a direct reading in
1.2 This standard does not purport to address all of the parts per million by volume of free water.
safety concerns, if any, associated with its use. It is the 5.2 Test Pads—Absorbent filter disks of 25-mm diameter
responsibility of the user of this standard to establish appro- shall be coated on one side with uranine (sodium fluorescein)
priate safety and health practices and determine the applica- dye at a concentration of 0.23 to 0.29 mg per 25 mm pad. The
bility of regulatory limitations prior to use. test pads shall be individually packaged in hermetically sealed
envelopes or other suitable containers. Fresh, unused test pads
2. Terminology
shall have an orange color over the dyed surface. Any
2.1 Definition of a Term Specific to This Standard: discoloration, unevenness in dye content, or faded (to a yellow
color) appearance shall be cause for rejection.
2.1.1 free water—water not dissolved in the fuel.
5.3 Test Pad Holder and Sampling Line—A test pad holder
3. Summary of Test Method
and sampling line shall be used to draw the fuel sample through
the test pad at a rate of 600 to 800 mL/min. Means shall be
3.1 A measured sample of fuel is passed through as uranine
provided to flush the test pad sampling line and holder
dye-treated filter pad. Undissolved (free) water in the fuel will
immediately prior to use. The test pad holder shall include an
react with the uranine dye. When the pad is subsequently
orifice of 1-mm (0.040-in.) diameter upstream of the pad to
illuminated by ultra violet (UV) light, the dye previously
disperse water droplets in the fuel.
contacted by free water will fluoresce a bright yellow with the
5.4 Tweezers—Suitable clean, dry tweezers shall be used at
brightness increasing for increasing amounts of free water in
all times when handling the test pad.
the fuel. The UV light-illuminated pad is compared to a known
5.5 Blotting Paper—Clean, dry, absorbent paper towels,
standard using a photocell comparator, and the free water in the
blotters, etc., shall be provided for blotting the test pad prior to
fuel sample is read out in parts per million by volume. By
rating to remove excess fuel. The blotterpaper shall neither
varying the fuel sample size, the range of the test method can
impart color or stain nor leave any residue on the test pads.
be increased.
5.6 Sampling Valve Connection, designed to meet the fol-
4. Significance and Use
lowing requirements: (1) It shall be mounted in the sampling
point and must incorporate a self-sealing quick action coupling
4.1 Undissolved (free) water in aviation fuel can encourage
the growth of microorganisms and subsequent corrosion in the
tanks of aircraft and can also lead to icing of filters in the fuel
The Aqua-Glo Series II instrument manufactured by Gammon Technical
system. Control of free water is exercised in ground fueling
Products, Inc., P.O. Box 400, Manasquan, NJ 08736-0400 was used in the precision
test program. The unit is currently available in a Series III configuration which is
equipment by use of filter-coalescers and water separators.
changed only in the power supply. All water content measuring components remain
of the same configuration as the Series II instrument. Manufacturers who wish to
offer similar products are referred to Committee D02 Equipment Replacement
This test method is under the jurisdiction of ASTM Committee D-2 on Guidelines.
Petroleum Products and Lubricantsand is the direct responsibility of Subcommittee Aqua-Glo test pads used in the Precision Test Program are available from
D02.Jon Aviation Fuels. Gammon Technical Products Inc., P.O. Box 400, Manasquan, NJ 08736-0400.
Current edition approved May 15, 1991. Published July 1991. Originally A test pad holder used in the Precision Test Program is available from Gammon
published as D 3240 – 73 T. Last previous edition D 3240 – 86a. Technical Products Inc., P.O. Box 400, Manasquan, NJ 08736-0400.
D 3240
designed to mate with a suitable connection leading to the calibration pad rating, adjust the photocell comparator by
selector valve of the sampling assembly. (2) It must be removing the plug screw on the side of the photocell compara-
completely resistant to fuel and be leak proof up to the tor at the 45° bend. Insert a small screwdriver, and adjust as
maximum working pressures to be encountered. (3) It must necessary. Repeat the above procedure until the rating obtained
have a minimum of internal recesses which could cause the agrees with the calibration pad rating. The instrument should
holdup of contaminant. (4) It must be provided with a dust cap. be calibrated prior to use each day, after each hour of use, and
5.7 Calibrating Standard, Calibration of the instrument when the ultra violet light battery is replaced or recharged.
should be performed using a calibrating standard of known
8. Rating Procedure
values.
8.1 Remove the test pad from the sampling holder using
6. Sampling
tweezers and press between dry paper blotters or absorbent
6.1 The following procedure is applicable for dynamic line towels to remove excess fuel. To blot, press firmly (about 5 lb
force) 3 or 4 times with heel of hand, moving the pad with
samples only; that is, taking the fuel sample directly from the
test system and through the test pad without exposing the tweezers each time.
8.1.1 For maximum accuracy the test pad should be read
sample to the atmosphere or to a sample container. The use of
sample containers such as bottles or cans for the temporary within 3 min after sampling is initiated. If the test pad is not
read immediately after sampling, it must be placed in a
storage of the sample will result in large errors and is not
recommended. desiccator to prevent moisture pickup from the air.
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