ASTM D3828 Test Methods for Flash Point by Small Scale Closed Cup Tester
METHOD A - FLASH/NO FLASH TEST
11. Procedure
11.1 For specification purposes carry out a flash/no flash test at a temperature (actual) that allows for a correction due to the ambient atmospheric pressure at the time of the test. Use the following equations to convert a specification flash point test requirement to the actual test temperature required for the test and then round to the nearest 0.5°C (1°F).
Actual test temperature, °C = Sc - 0.25(101.3 - A)
Actual test temperature, °C = Sc - 0.03(760 - B)
Actual test temperature, °F = Sf - 0.06(760 - B)
where:
Sc = specification, or uncorrected target test temperature, °C,
Sf = specification, or uncorrected target test temperature, °F,
B = ambient barometric pressure, mm Hg, and
A = ambient barometric pressure, kPa.
11.2 Inspect the test cup and cover for cleanliness and correct operation, especially with regard to tightness of the cover (A1.2.1), the action of the shutter, the size or intensity of the ignition source and the position of the ignition source (A1.3). Clean if necessary (9.3). Put the cover in place and close securely.
11.3 Follow the manufacturer's instructions to set the test temperature and the test time, and select the test specimen volume in accordance with Table 1.
11.4 When the test cup is at the test temperature, fill the appropriate syringe (A1.5, A1.6) with the sample to be tested; transfer the syringe to the filling orifice, taking care not to lose any sample; discharge the test specimen into the test cup by fully depressing the syringe plunger; remove the syringe.
11.5 Start the test timer; light the pilot light and adjust the test flame (if used) to conform to the 4 mm (5/32 in.) gauge.
11.6 When the end of the test time is indicated, apply the ignition source by slowly and uniformly opening the shutter and closing it completely over a period of 2 1/2 s. Watch closely for a flash at the test cup openings.
11.6.1 The test specimen is deemed to have flashed when a large flame appears and instantaneously propagates itself over the surface of the test specimen (see 3.1.2). Occasionally, particularly near the actual flash point, application of the ignition source can cause a blue halo or an enlarged flame; this is not a flash and should be ignored.
11.7 Record the test result as flash (or no flash) and the test temperature.
11.8 Turn off the pilot and test flames (if used). Remove the test specimen and clean the test cup and cover. It may be necessary to allow the test cup temperature to fall to a safe level before cleaning.
