ASTM D93:16 pdf free download – Standard Test Methods for Flash Point by Pensky-Martens Closed Cup Tester.
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 s. left in its lowered position for 1 s, and quickly raised to its upward position.
11.1.5.2 lithe test specimen is expected to have a flash point above I 10 °C or 230 cF. apply the ignition source in the manner described in Il. 1.5.1 at each temperature increase of 2 °C or 5 DF. beginning at a temperature of 23 UC ± 5 °C or 41 F ± 9 F 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 °C, to dip the ignitor every 10°C throughout the test until the sample temperature reaches 28 °C 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 study5 has shown that this dipping practice has no observable eflct on test method repeatability.)
II . 1.6 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.
11.1.7 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 °C ± 5 C or 60 F ± 10 F. When the material is known to be very viscous at this temperature, heat the specimen to a starting temperature as described in 8.6. Apply the ignition source, in the manner described in 11.1.5.1. beginning at least 5 C or IOLF higher than the starting temperature.
Note 9—Flash Point results dctcnnined in an “unknown expected flash point m*lc” 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.
11.1.8 Record as the observed flash point the reading on 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 change in color of the test flame from blue to yellowish-orange occurs. Continued heating and testing of these samples above ambient temperature can result in significant burning of vapors outside the test cup, and can be a potential fire ha,ard. See Appendix XI and Appendix X2 for more information.)
II. 1.9 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.