[Code of Federal Regulations]
[Title 16, Volume 2]
[Revised as of January 1, 2007]
From the U.S. Government Printing Office via GPO Access
[CITE: 16CFR1500.43a]
[Page 442-449]
TITLE 16--COMMERCIAL PRACTICES
CHAPTER II--CONSUMER PRODUCT SAFETY COMMISSION
PART 1500_HAZARDOUS SUBSTANCES AND ARTICLES; ADMINISTRATION AND
ENFORCEMENT REGULATIONS--Table of Contents
Sec. 1500.43a Method of test for flashpoint of volatile flammable materials.
(a) Scope. (1) This method describes the test procedure which the
Commission will use for the determination of the flashpoint of volatile
flammable materials, using a Setaflash \1\ low-range closed tester, or
an apparatus producing equivalent results. The method described in this
section is essentially a Setaflash equilibrium procedure which closely
parallels the test method designated ASTM D 3828-81, ``Standard Test
Methods for Flash Point by
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Setaflash Closed Tester,'' published by the American Society for Testing
and Materials (ASTM), 1916 Race Street, Philadelphia, Pennsylvania
19103. Manufacturers and labelers of products subject to labeling and
other requirements under the Federal Hazardous Substances Act may use
other apparatus and/or test methods which produce equivalent results.
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\1\ Setaflash is a registered trademark of Stanhope-Seta Limited,
Surrey, England.
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(2) At the option of the user, the procedures described in this
section may be used to determine the actual flashpoint temperature of a
sample or to determine whether a product will or will not flash at a
specified temperature (flash/no flash).
(3) If the substance to be tested has a viscosity greater than 150
Stokes at 77 [deg]F (25 [deg]C), see paragraph (n) of this section for
modifications to the testing procedure.
(4) If the Commission has reason to believe on the basis of reliable
experience or other relevant information or data that the flammability
hazard of a substance is greater or less than its flammability
classification based on flashpoint temperature determined in accordance
with this Sec. 1500.43a and that the substance should be reclassified,
the Commission will initiate a rulemaking proceeding for
reclassification of the substance. Product manufacturers and labelers
may use reliable experience or other relevant information or data in
addition to the flashpoint temperature of a substance as a basis for
compliance with any applicable requirements of the Federal Hazardous
Substances Act in the absence of a rule issued by the Commission to
reclassify the substance.
(b) Summary of test methods. (1) Method A--Flash/No Flash Test. A
specified volume of sample is introduced by a syringe into the cup of
the apparatus that is set and maintained at the specified temperature.
After a specific time a test flame is applied and an observation made as
to whether or not a flash occurred. Test procedures are set forth in
detail in Sec. 1500.43a(i).
(2) Method B--Finite (or Actual) Flashpoint. (i) A specified voume
of sample is introduced into the cup of the apparatus that is maintained
at the expected flashpoint. After a specified time a test flame is
applied and the observation made whether or not a flash occurred.
(ii) The specimen is removed from the cup, the cup cleaned, and the
cup temperature adjusted 5 [deg]C (9 [deg]F), lower or higher depending
on whether or not a flash occurred previously. A fresh specimen is
introduced and tested. This procedure is repeated until the flashpoint
is established within 5 [deg]C (9 [deg]F).
(iii) The procedure is then repeated at 1 [deg]C (2 [deg]F)
intervals until the flashpoint is determined to the nearest 1 [deg]C (2
[deg]F).
(iv) If improved accuracy is desired the procedure is repeated at
0.5 [deg]C (1 [deg]F). Test procedures are set forth in detail at Sec.
1500.43a(j).
(3) The test procedures will be modified, where necessary, to ensure
that the results obtained reflect the hazard of the substance under
reasonably foreseeable conditions of use. Thus, for example, the
material, if a mixture, will normally be tested as it comes from the
container, and/or after a period of evaporation. The period of
evaporation for a material which is a mixture will normally be the time
required for the mixture to evaporate in an open beaker under ambient
conditions to 90 percent of its original volume, or a period of four
hours, whichever occurs first. However, this period of evaporation will
be changed if the results obtained do not represent the hazard of the
substance under reasonably foreseeable conditions of use.
(c) Definition of flashpoint. The lowest temperature of the sample,
corrected to a barometric pressure of 101.3 kPa (760 mm Hg), at which
application of a test flame causes the vapor of the sample to ignite
under specified conditions of test. The sample is deemed to have flashed
when a large flame appears and instantaneously propagates itself over
the surface of the sample. Occasionally, particularly near actual
flashpoint, the application of the test flame will cause a halo or an
enlarged flame; this is not a flash and should be ignored.
(d) Test apparatus. The test apparatus is an equilibrium closed-cup
tester with a range up to 100 [deg]C (212 [deg]F). The essential
dimensions and requirements are shown in figure 1 and table 3, and
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are described in Sec. 1500.43a(m). Closed-cup flashpoint testers and
accessories meeting these requirements are available from commercial
suppliers and distributors of laboratory equipment.
(e) Safety precautions. The operator must exercise and take
appropriate safety precautions during the initial application of the
test flame to the sample. Samples containing low-flash material may give
an abnormally strong flash when the test flame is first applied.
(f) Preparation of samples. (1) Erroneously high flashpoints may be
obtained if precautions are not taken to avoid the loss of volatile
material. In preliminary tests of materials taken directly from the
container, do not open containers unnecessarily and make a transfer
unless the sample temperature is at least 10 [deg]C (18 [deg]F) below
the expected flashpoint. Do not use samples in leaky containers for this
test.
(2) Do not store samples in plastic (polyethylene, polypropylene,
etc.) bottles since volatile material may diffuse through the walls of
the bottle.
(3) A 2-ml specimen is required for each test. If possible, obtain
at least a 50-ml sample from the bulk test site and store in a clean,
tightly closed container.
(g) Preparation of apparatus. (1) Place the tester on a level,
stable surface. Unless tests are made in a draft-free area, surround the
tester on three sides with a shield for protection. Do not rely on tests
made in a laboratory draft hood or near ventilators.
(2) Read the manufacturer's instructions on the care and servicing
of the instrument and for correct operation of its controls.
(h) Calibration and standardization. (1) Before initial use
determine and plot the relationship between the temperature control dial
and the thermometer readings at each major (numbered) dial division as
follows:
Turn the temperature control knob \2\ fully counterclockwise (``O''
reading). Advance the temperature control knob clockwise until the
indicator light is illuminated.\3\ Advance the knob clockwise to the
next numbered line. After the thermometer mercury column ceases to
advance, record the dial reading and the temperature. Advance the knob
clockwise to the next numbered line. After the thermometer mercury
column ceases to advance, read the dial reading and the temperature.
Repeat this procedure through the full range of the instrument. Plot the
dial readings versus the respective temperatures.
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\2\ If the instrument has two temperature control knobs, set the
fine control (center, small knob) at its mid-position and allow it to
remain there throughout the calibration. The calibration is determined
by adjusting the coarse control (large, outer knob) only.
\3\ When using the tester, it will be found that the indicator light
may not illuminate and the temperature may not rise until a temperature
control dial setting between one and two is reached.
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(2) Standardize the instrument using a sample of material meeting
the specifications in table 1. If the average of two determinations
falls within the acceptable limits the instrument is assumed to be
operating properly. If the average of the two determinations does not
fall within this range, check the manufacturer's operating and
maintenance instructions and determine that they are being followed. In
particular, be sure that the cup lid assembly makes a vapor-tight seal
with the cup, the shutter provides a light-tight seal, and that adequate
heat transfer paste surrounds the thermometer bulb and the immersed
portion of the barrel.
(i) Test Method A--for determining Flash/No Flash. (1) Determine the
target flashpoint as follows:
(i) Target flashpoint, [deg]C=Sc--0.25 (101.3--A)
(ii) Target flashpoint, [deg]C=Sc--0.03 (760-B)
(iii) Target flashpoint, [deg]F=Sf--0.06 (760-B)
where:
Sc=specification, or uncorrected target, flashpoint, [deg]C,
Sf=specification, or uncorrected target, flashpoint, [deg]F,
B=ambient barometric pressure, mm Hg,\4\ and
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\4\ The barometric pressure used in this calculation must be the
ambient pressure for the laboratory at the time of test. Many aneroid
barometers, such as those used at weather stations and airports, are
precorrected to give sea-level readings; these must not be used.
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[[Page 445]]
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A=ambient barometer pressure, kPa.\4\
(2) Inspect the inside of the sample cup, lid, and shutter mechanism
for cleaniness and freedom from contamination. Use an absorbent paper
tissue to wipe clean, if necessary. Put cover in place and lock
securely. The filing orifice may be convenienty cleaned with a pipe
cleaner.
(3) Set the instrument at the target temperature.
(i) For target temperature below ambient. The instrument power
switch is to be in the off position. Fill the refigerant-charged cooling
block with a suitable material.\5\ Raise the lid and shutter assembly,
and position the base of the block in the sample cup, being careful not
to injure or mar the cup. When the thermometer reads approximately 6 to
10 [deg]C (10 to 20 [deg]F) below the target temperature, remove the
cooling block and quickly dry the cup with a paper tissue to remove any
moisture. Immediately close the lid and shutter assembly and secure.
Prepare to introduce the sample using the syringe, both of which have
been precooled to a temperature 5 to 10 [deg]C (10 to 20 [deg]F) below
the target temperature.
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\5\ If the target or specification temperature is not less than 5
[deg]C (40 [deg]F) crushed ice and water may be used as charging
(cooling) fluid. If below 5 [deg]C (40 [deg]F), a suitable charging
(cooling) fluid is solid carbon dioxide (dry ice) and acetone. If the
refrigerant charged cooling module is unavailable, refer to the
manufacturer's instruction manual for alternative methods of cooling.
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(A) Caution: Do not cool the sample block below -38 [deg]C, the
freezing point of mercury.
(B) Caution: Acetone is extremely flammable. Keep away from heat,
sparks, and flames and keep container closed when not actually pouring
acetone. Use only in a well-ventilated area. Avoid inhalation and
contact with the eyes or skin. Use cloth or leather gloves, goggles or
safety shield, and keep dry ice in a canvas bag, especially when
cracking.
(ii) For target temperature above ambient. Switch the instrument on
and turn the coarse temperature control knob fully clockwise (full on)
causing the indicator light to illuminate.\6\ When the thermometer
indicates a temperature about 3 [deg]C (5 [deg]F) below the target (or
specification) temperature, reduce the heat input to the sample cup by
turning the coarse temperature control knob counter-clockwise to the
desired control point (see Sec. 1500.43a(i)(1)). When the indicator
light slowly cycles on and off read the temperature on the thermometer.
If necessary, adjust the fine (center) temperature control knob to
obtain the desired test (target) temperature. When the test temperature
is reached and the indicator lamp slowly cycles on and off, prepare to
introduce the sample.
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\6\ The target temperature may be attained by originally turning the
coarse temperature control knob to the proper setting (see Sec.
1500.43a(h)(1) for the temperature desired rather than the maximum
setting (full on). The elapsed time to reach the temperature will be
greater, except for maximum temperature. However, less attention will be
required during the intervening period.
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(4) Charge the syringe with a 2-ml specimen of the sample \7\ to be
tested; transfer the syringe to the filling orifice, taking care not to
lose any sample; discharge the test specimen into the cup by fully
depressing the syringe plunger, remove the syringe.
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\7\ For target or expected temperatures below ambient, both syringe
and sample must be precooled to cup temperature (see Sec.
1500.43a(i)(3)(i)) before the specimen is taken.
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(5)(i) Set the timer \8\ by rotating its knob clockwise to its stop.
Open the gas control valve and light the pilot and test flames. Adjust
the test flame with the pinch valve to conform to the size of the 4-mm
(5/32-in.) gage.
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\8\ For target temperatures below ambient, do not set the timer.
Adjust the test flame and allow the temperature to rise under ambient
conditions until the target temperature is reached. Immediately apply
the test flame as detailed.
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(ii) After the time signal indicates the specimen is at test
temperature \8\, apply the test flame by slowly and uniformly opening
the shutter and closing it completely over a period of approximately
2\1/2\ s.\9\ Watch closely for a flash at the cup openings.
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\9\ Never apply the test flame to the specimen more than once. Fresh
portions of the sample must be used for each test.
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[[Page 446]]
(iii) The sample is deemed to have flashed when a large flame
appears and instantaneously propagates itself over the surface of the
sample (see Sec. 1500.43a(c)).
(6) Record the test results as ``flash'' or ``no flash'' and the
test temperature.
(7) Turn off the pilot and test flames using the gas control valve.
Remove the sample and clean the instrument. It may be necessary to allow
the cup temperature to decline to a safe level before cleaning.
(j) Test Method B--for determining Finite or Actual Flashpoint. (1)
Inspect the inside of the sample cup, lid, and shutter mechanism for
cleanliness and freedom from contamination. Use an absorbent paper
tissue to wipe clean, if necessary. Put cover in place and lock
securely. The filling orifice may be conveniently cleaned with a pipe
cleaner.
(2) For expected flashpoints below ambient. (i) The instrument power
switch is to be in off position. Fill the refrigerant-charged cooling
block with a suitable material.\5\ Raise the lid and shutter assembly,
and position the base of the block in the sample cup, being careful not
to injure or mar the cup. When the thermometer reaches a temperature 5
to 10 [deg]C (10 to 20 [deg]F) below the expected flashpoint, remove the
cooling block and quickly dry the cup with a paper tissue to remove any
moisture. Immediately close the lid and shutter assembly and secure.
Prepare to introduce the sample using the syringe, both of which have
been precooled to a temperature 5 to 10 [deg]C (10 to 20 [deg]F) below
the expected temperature (See Sec. 1500.43a(j)(5)).
(ii) Caution: Do not cool the sample block below -38 [deg]C, the
freezing point of mercury.
(3) For tests where the expected flashpoint is above ambient. Turn
the coarse temperature control knob fully clockwise (full on) causing
the indicator light to illuminate. When the thermometer reaches a
temperature 3 [deg]C (5 [deg]F) below the estimated flashpoint, turn the
coarse temperature knob counter-clockwise to the dial reading
representing the estimated flashpoint temperature as shown on the
calibration curve (See Sec. 1500.43a(h)(1)). When the indicator light
slowly cycles on and off, read the temperature on the thermometer. If
necessary, adjust the fine temperature control knob to obtain the exact
desired temperature.
(4)(i) Charge the syringe \7\ with a 2 ml specimen of the sample \7\
to be tested; transfer the syringe to the filling orifice, taking care
not to lose any sample; discharge the test specimen into the cup by
fully depressing the syringe plunger; remove the syringe.
(ii) Set the timer \10\ by rotating its knob clockwise to its stop.
Open the gas control valve and ignite the pilot and test flames. Adjust
the test flame with the pinch valve to conform to the size of the 4-mm
(\5/32\-in.) gage.
(iii) After the audible time signal indicates the specimen is at
test temperature,\10\ apply the test flame by slowly and uniformly
opening the shutter and then closing it completely over a period of
approximately 2\1/2\ s. Watch closely for a flash at the cup opening.
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\10\ For expected flashpoint below ambient, do not set the timing
device. Adjust the test flame. Allow the temperature to rise under
ambient conditions until the temperature reaches 5 [deg]C (9 [deg]F)
below the expected flashpoint. Immediately apply the test flame.
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(iv) The sample is deemed to have flashed only if a large flame
appears and instantaneously propagates itself over the surface of the
sample. (See Sec. 1500.43a(c).)
(v) Turn off the pilot and test flames using the gas control valve.
When the cup temperature declines to a safe level, remove the sample and
clean the instrument.
(5)(i) If a flash was observed in Sec. 1500.43a(j)(4)(iii) repeat
the procedure given in Sec. 1500.43a(j)(2) or (3), and in Sec.
1500.43a(j)(4), testing a new specimen at a temperature 5 [deg]C (9
[deg]F) below that at which the flash was observed.
(ii) If necessary, repeat the procedure in Sec. 1500.43a(j)(5)(i),
lowering the temperature 5 [deg]C (9 [deg]F) each time, until no flash
is observed.\9\
(iii) Proceed to Sec. 1500.43a(j)(7).
(6)(i) If no flash was observed in Sec. 1500.43a(j)(4)(iii) repeat
the procedure given in Sec. 1500.43a(j)(2) or (3), and in Sec.
1500.43a(j)(4), testing a fresh specimen at a temperature 5 [deg]C (9
[deg]F) above that
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at which the specimen was tested in Sec. 1500.43a(j)(4)(iii).
(ii) If necessary repeat the procedure in Sec. 1500.43a(j)(6)(i),
above, raising the temperature 5 [deg]C (9 [deg]F) each time until a
flash is observed.\9\
(7) Having established a flash within two temperatures 5 [deg]C (9
[deg]F) apart, repeat the procedure at 1 [deg]C (2 [deg]F) intervals
from the lower of the two temperatures until a flash is observed.\9\
Record the temperature of the test when this flash occurs as the
flashpoint, allowing for any known thermometer correction. Record the
barometric pressure.\4\
(8) The flashpoint determined in Sec. 1500.43a(j)(7) will be to the
nearest 1 [deg]C (2 [deg]F). If improved accuracy is desired (that is,
to the nearest 0.5 [deg]C (1 [deg]F)), test a fresh specimen at a
temperature 0.5 [deg]C (1 [deg]F) below that at which the flash was
observed in Sec. 1500.43a(j)(7). If no flash is observed, the
temperature recorded in Sec. 1500.43a(j)(7), is the flashpoint to the
nearest 0.5 [deg]C (1 [deg]F). If a flash is observed at the lower
temperature, record this latter temperature as the flashpoint.
(9) Turn off the pilot and test flames using the gas control valve.
When the cup temperature declines to a safe level, remove the sample and
clean the instrument.
(k) Calculations. If it is desired to correct the observed finite
flashpoint for the effect of barometric pressure, proceed as follows:
Observe and record the ambient barometric pressure\4\ at the time of the
test. If the pressure differs from 101.3 kPa (760 mm Hg), correct the
flashpoint as follows:
(1) Corrected flashpoint ( [deg]C)=C+0.25 (101.3-A)
(2) Corrected flashpoint ( [deg]F)=F+0.06 (760-B)
(3) Corrected flashpoint ( [deg]C)=C+0.03 (760-B)
Where: F=Observed flashpoint, [deg]F,
C=observed flashpoint, [deg]C,
B=ambient barometric pressure, mm Hg; and
A=ambient barometric pressure, kPa.
(l) Precision. The precision of the method as determined by
statistical examination of interlaboratory results is as follows:
(1) Repeatability. The difference between two test results obtained
by the same operator with the same apparatus under constant operating
conditions on identical test material, would, in the long run, in the
normal and correct operation of the test method, exceed the values shown
in table 2 only in 1 case in 20.
(2) Reproducibility. The difference between two single and
independent results obtained by different operators working in different
laboratories on identical test material, would, in the long run, in the
normal and correct operation of the test method, exceed the values shown
in table 2 only in 1 case in 20.
(m) Flash Test Apparatus. (1)(i) Unit consisting of an aluminum
alloy or nonrusting metal block of suitable conductivity with a
cylindrical depression, or sample cup, over which is fitted a cover. A
thermometer is embedded in the block.
(ii) The cover is fitted with an opening slide and a device capable
of inserting an ignition flame (diameter 40.5 mm)
into the well when the slide device shall intersect the plane of the
underside of the cover. The cover is also provided with an orifice
extending into the sample well for insertion of the test sample and also
a suitable clamping device for securing the cover tightly to the metal
block. The three openings in the cover shall be within the diameter of
the sample well. When the slide is in the open position, the two
openings in the slide shall coincide exactly with the two corresponding
openings in the cover.
(iii) Electrical heaters are attached to the bottom of the cup in a
manner that provides efficient transfer of heat. An electronic heat
control is required to hold the equilibrium temperature, in a draft-free
area, within 0.1 [deg]C (0.2 [deg]F) for the low-temperature tester. A
visual indicator lamp shows when energy is or is not being applied.
Energy may be supplied from 120 or 240 V, 50 or 60 Hz main service.
(2)(i) Test flame and pilot flame-regulatable test flame, for
dipping into the sample cup to try for flash, and a pilot flame, to
maintain the test flame, are required. These flames may be fueled by
piped gas service. A gage ring 4mm (5/32 in.) in diameter, engraved on
the lid near the test flame, is required to ensure uniformity in the
size of the test flame.
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(ii) Caution: Never recharge the self-contained gas tank at elevated
temperature, or with the pilot or test flames lighted, nor in the
vicinity of other flames.
(iii) Audible Signal is required. The audiable signal is given after
1 min in the case of the low-temperature tester.
(iv) Syringe. 2ml capacity, equipped with a needle suitable for use
with the apparatus, adjusted to deliver 2.000.05
ml.
(3) Essential dimensions of the test apparatus are set forth in
table 3.
(n) Testing high-viscosity liquids. (1) High-viscosity materials may
be added to the cup by the following procedure:
(i) Back load a 5 or 10-ml syringe with the sample to be tested and
extrude 2 ml into the cup. Spread the specimen as evenly as possible
over the bottom of the cup.
(ii) If the sample cannot be loaded into a syringe and extruded,
other means of adding the sample to the cup may be used such as a spoon.
Add approximately 2 ml of material to the spoon and then push the
material from the spoon into the cup.
(iii) If the test specimen does not close the sampling port in the
cup, seal the cup externally by suitable means.
(2) Using the appropriate procedure, either Method A in Sec.
1500.43a(i) or Method B in Sec. 1500.43a(j), determine the flashpoint
of the specimen which has been added to the tester in accordance with
Sec. 1500.43a(n)(i), except that the time specified is increased from 1
to 5 minutes for samples at or above ambient temperature.
Table 1--Calibration of Tester
Material.................................. p-xyleneA (Caution).B
Specific gravity. 15.6/15.6 [deg]C (60/60 0.850 to 0.866.
[deg]F).
Boiling range............................. 2 [deg]C maximum including
138.35 [deg]C (281.03
[deg]F).
Freezing point............................ 11.23 [deg]C (52.2 [deg]F)
minimum.
Flashpoint [deg]C (acceptable range)...... 25.60.5 (781 [Phi]).
A Available as Flash Point Check Fluid (p-xylene) from Special Products
Div., Phillips Petroleum Co., Drawer `O,' Borger, Texas 79007.
B Caution: Handle xylene with care. Avoid inhalation; use only in a well-
ventilated area. Avoid prolonged or repeated contact with skin. Keep
away from flames and heat, except as necessary for the actual flash
point determination.
Table 2--Repeatability and Reproducibility
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Repeatability,
Temperature, [deg]C ( [deg]F) [deg]C ( Reproducibility,
[deg]F) [deg]C ( [deg]F)
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20(68)................................ 0.5(0.9) 1.4(2.6)
70(158)............................... 0.5(0.9) 2.9(5.3)
93(200)............................... 1.3(2.3) 4.9(8.8)
150(300).............................. 2.0(3.6) 7.5(13.5)
200(400).............................. 2.6(4.7) 9.9(17.9)
260(500).............................. 3.3(5.9) 12.4(22.3)
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Table 3--Essential Dimensions of Flash Test Apparatus A,B
Sample Block
Block diameter............................................ 61.5-62.5
Sample well diameter...................................... 49.40-49.70
Sample well depth......................................... 9.70-10.00
Top of block to center of thermometer hole................ 16.00-17.00
Diameter of thermometer hole (approx.).................... 7.0004
Cover
Large opening length...................................... 12.42-12.47
Large opening width....................................... 10.13-10.18
Small opening length...................................... 5.05-5.10
Small opening width....................................... 7.60-7.65
Distance between extreme edges of small openings.......... 48.37-48.32
Filling orifice diameter.................................. 4.00-4.50
Bore or filler tube....................................... 1.80-1.85
Maximum distance of filler tube from base of well with 0.75
cover closed (max.)......................................
Slide
Large opening length...................................... 12.42-12.47
Large opening width....................................... 10.13-10.18
Small opening length...................................... 5.05-5.10
Small opening width....................................... 7.60-7.65
Near edge of large opening to end of slide................ 12.80-12.85
Extremes of large and small openings...................... 30.40-30.45
Jet
Length of jet............................................. 18.30-18.40
External diameter at end of jet........................... 2.20-2.60
Bore of jet............................................... 1.60-1.65
Height of jet center above top surface of cover........... 11.00-11.20
Jet pivot to center of block with cover closed............ 12.68-12.72
A The O-seal or gasket which provides a seal when the cover is shut,
should be made of a heat-resistant material capable of withstanding
temperatures up to 150 [deg]C for the low-range apparatus.
B When in position, the thermometer bulb should be surrounded with heat-
conducting thermoplastic compound, such as a paste comprised of zinc
oxide and mineral oil.
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[GRAPHIC] [TIFF OMITTED] TC03OC91.054
[51 FR 28539, Aug. 8, 1986]