ASTM D3828 Test Methods for Flash Point by Small Scale Closed Cup Tester
6. Apparatus
6.1 Test Cup and Cover Assembly - The essential dimensions and requirements of the apparatus are shown in Fig. A1.1 and Table A1.1 of Annex A1. The apparatus and accessories are described in detail in Annex A1. The temperature range is from -30 to 300°C. Some versions of the apparatus may not cover the full temperature range.
6.2 Barometer, accurate to 0.5 kPa. Barometers that have been pre-corrected for use at weather stations or airports are not suitable.
6.3 Draft Shield - A shield located at the back and on two sides of the instrument, for use in circumstances where protection from drafts does not exist.
7. Reagents and Materials
7.1 Cleaning Solvent - Use only non-corrosive solvents capable of cleaning the test cup and cover. Two commonly used solvents are toluene and acetone. (Warning - Toluene, acetone and many other solvents are flammable and a health hazard. Dispose of solvents and waste material in accordance with local regulations.)
7.2 Butane, Propane and Natural Gas - For use as a pilot and ignition source (not required if an electric ignitor is used). (Warning - Butane, propane and natural gases are flammable and a health hazard.)
8. Sampling
8.1 Obtain at least a 50 mL sample from a bulk test site in accordance with Practices D4057, D4177, E 300 or other comparable sampling practices.
8.2 Store samples in clean, tightly sealed containers at normal room temperature (20 to 25°C) or colder.
8.3 Do not store samples for an extended period of time in gas permeable containers, such as those made of plastic, because volatile material can diffuse through the walls of the container. Samples in leaky containers are suspect and not a source of valid results.
8.4 Erroneously high flash points can be obtained when precautions are not taken to avoid loss of volatile materials. Do not open containers unnecessarily. Do not make a transfer unless the sample temperature is at least 10°C below the expected flash point. Where possible perform the flash point as the first test on the sample.
8.5 Samples containing dissolved or free water may be dehydrated with calcium chloride. (Warning - If the sample is expected of containing volatile components, the treatment as described in 8.5 should be omitted.)
8.6 Cool, or adjust the temperature of the sample and its container to at least 10°C below the expected flash point before opening to remove the test specimen. If an aliquot of the original sample is to be stored prior to testing, ensure that the container is filled to between 85 and 95 % of its capacity.
NOTE 1 - Results of flash point tests can be affected if the sample volume falls below 50 % of the container's capacity.
8.7 If sufficiently fluid, mix samples by gently shaking by hand prior to removal of the test specimen, taking care to minimize the loss of volatile components. If the sample is too viscous at ambient temperature, gently warm the sample in its container to a temperature not warmer than 10°C below the test temperature, such that the sample can be mixed by gentle shaking.
8.8 If the sample cannot be made sufficiently fluid to be introduced into the test cup through the orifice by heating in accordance with 8.7, transfer the test specimen with a solids dispenser or spatula while the cover is open. The specimen size can be the mass equivalent of the required volume and the specimen should be spread over the bottom of the test cup as evenly as possible. Precision has not been determined for solid samples.
