D93_11 Procedure A (16A)

Ensure that the sample container is filled to the volume capacity requirements specified in 8.2 of the written standard. Fill the test cup with the test specimen to the filling mark inside of the test cup. The temperature of the test cup and the test specimen shall be at least 18 degrees Celsius or 32 degrees Fahrenheit below the expected flash point. If too much test specimen has been added to the test cup, remove the excess using a syringe or similar device for withdrawal of fluid. Place the test cover on the test cup, and place the assembly into the apparatus. Be sure the locating or locking device is properly engaged. If the temperature measuring device is not already in place, insert the device into its holder. Light the test flame, and adjust it to a diameter of 3.2 millimeters to 4.8 millimeters, 0.126 inches to 0.189 inches, or switch on the electric igniter and adjust the intensity in accordance with the manufacturer's instructions. Warning. Gas pressure should not be allowed to exceed 3 kilopascals, 12 inches of water pressure. Warning. Exercise care when using a gas test flame. If it should be extinguished, it will not ignite the vapors in the test cup and the gas for the test flame that then enters the vapor space can influence the result. Warning. The operator should exercise and take appropriate safety precautions during the initial application of the ignition source, since test specimens containing low flash material can give an abnormally strong flash when ignition source is first applied. Warning. The operator should exercise and take appropriate safety precautions during the performance of these test methods. The temperatures attained during these test methods up to 370 degrees Celsius, 698 degrees Fahrenheit, are considered hazardous. Warning. As a safety practice when using automated or manual apparatus, it is strongly advised, before heating the test cup in specimen, to dip the igniter to check for the presence of unexpected volatile material. Apply the heat at such a rate that the temperature as indicated by the temperature measuring device increases 5 degrees Celsius to 6 degrees Celsius, 9 degrees Fahrenheit to 11 degrees Fahrenheit, per minute. Turn the stirring device to 90 revolutions per minute to 120 revolutions per minute, stirring in a downward direction. Warning. Meticulous attention to all details relating to the ignition source, size of test flame, or intensity of the electric igniter, rate of temperature increase, and rate of dipping the ignition source into the vapor of the test specimen is desirable for good results. If the test specimen is expected to have a flash point of 110 degrees Celsius, or 230 degrees Fahrenheit or below, apply the ignition source when the temperature of the test specimen is 23 degrees Celsius plus or minus 5 degrees Celsius, or 41 degrees Fahrenheit plus or minus 9 degrees Fahrenheit, below the expected flash point, and each time thereafter at a temperature reading that is a multiple of 1 degree Celsius or 2 degrees Fahrenheit. Discontinue the stirring of the test specimen, and apply the ignition source by operating the mechanism on the test cover which controls the shutter so that the ignition source is lowered into the vapor space of the test cup in 0.5 seconds, left in its lowered position for one second, and quickly raised to its upward position. If the test specimen is expected to have a flash point above 110 degrees Celsius or 230 degrees Fahrenheit, apply the ignition source in the manner described in 11.1.5.1 of the written standard at each temperature increase of 2 degrees Celsius, or 5 degrees Fahrenheit, beginning at a temperature of 23 degrees Celsius plus or minus 5 degrees Celsius, or 41 degrees Fahrenheit plus or minus 9 degrees Fahrenheit, below the expected flash point. Warning. As a safety practice when using automated or manual apparatus, it is strongly advised that, for an expected flash point above 130 degrees Celsius, to dip the igniter every 10 degrees Celsius throughout the test until the sample temperature reaches 28 degrees Celsius below the expected flash point, and then follow the prescribed dipping procedure. This practice has been shown to reduce the possibility of a fire and, on average, not to significantly affect the result. A limited study has shown that this dipping practice has no observable effect on test method repeatability. When testing materials to determine if volatile material contamination is present, it is not necessary to adhere to the temperature limits for initial ignition source application as stated in 11.1.5 of the written standard. When testing materials where the expected flash point temperature is not known, bring the material to be tested and the tester to a temperature of 15 degrees Celsius plus or minus 5 degrees Celsius, or 60 degrees Fahrenheit plus or minus 10 degrees Fahrenheit. When the material is known to be very viscous at this temperature, heat the specimen to a starting temperature as described in 8.6 of the written standard. Apply the ignition source in the manner described in 11.1.5.1 of the written standard, beginning at least 5 degrees Celsius or 10 degrees Fahrenheit higher than the starting temperature. Flash point results determined in an unknown expected flash point mode should be considered approximate. This value can be used as the expected flash point when a fresh specimen is tested in the standard mode of operation. Record as the observed flash point, the reading of the temperature measuring device at the time ignition source application causes a distinct flash in the interior of the test cup. The sample is deemed to have flashed when a large flame appears and instantaneously propagates itself over the entire surface of the test specimen. Warning. For certain mixtures containing halogenated hydrocarbons, such as methylene chloride, or trichloroethylene, no distinct flash as defined is observed. Instead, a significant enlargement of the test flame, not halo effect, and changing color of the test flame from blue to yellowish-orange occurs. Continued heating and testing of the samples above ambient temperature can result in significant burning of vapors outside of the test cup and can be a potential fire hazard. See appendix X1 and appendix X2 of the written standard for more information. When the ignition source is a test flame, the application of the test flame can cause a blue halo or an enlarged flame prior to the actual flash point. This is not a flash and shall be ignored. When a flash point is detected on the first application, the test shall be discontinued, the result discarded, and the test repeated with a fresh test specimen. The first application of the ignition source with the fresh test specimen shall be 23 degrees Celsius plus or minus 5 degrees Celsius, or 41 degrees Fahrenheit plus or minus 9 degrees Fahrenheit, below the temperature at which a flash point was detected on the first application. When a flash point is detected at a temperature which is greater than 28 degrees Celsius or 50 degrees Fahrenheit above the temperature of the first application of the ignition source, or when a flash point is detected at a temperature which is less than 18 degrees Celsius or 32 degrees Fahrenheit above the temperature of the first application of the ignition source, the result shall be considered approximate and the test repeated with a fresh test specimen. Adjust the expected flash point for this next test to the temperature of the approximate result. The first application of the ignition source with the fresh test specimen shall be 23 degrees Celsius plus or minus 5 degrees Celsius, or 41 degrees Fahrenheit plus or minus 9 degrees Fahrenheit, below the temperature at which the approximate result was found. When the apparatus has cooled down to a safe handling temperature, less than 55 degrees Celsius, 130 degrees Fahrenheit, remove the test cover and the test cup and clean the apparatus as recommended by the manufacturer. Exercise care when cleaning and positioning the lid assembly so not to damage or dislocate the flash detection system or temperature measuring device. See the manufacturer's instructions for proper care and maintenance. The automated apparatus shall be capable of performing the procedure as described in 11.1 of the written standard, including control of the heating rate, stirring of the test specimen, application of the ignition source, detection of the flash point, and recording the flash point. Store the automated apparatus in accordance with the manufacturer's instructions. Warning. Failure to install the sample temperature measuring device correctly when using automated apparatus can result in uncontrolled heating of the test portion and potentially a fire. Some automated apparatus include provisions to avoid this occurrence. The apparatus shall follow the procedural details described in 11.1.3 through 11.1.8 of the written standard.