ISO 3679 Determination of flash point - Rapid equilibrium closed cup method
8 Sampling
8.1 Unless otherwise specified, obtain samples in accordance with the procedures given in ISO 15528, ISO 3170 or ISO 3171 or an equivalent national standard.

8.2 Place sufficient sample volume for testing in a tightly sealed container made of material appropriate to the liquid being sampled, and for safety purposes, ensure that the sample container is only filled to between 85 % and 95 % of its capacity.

If more than one determination is anticipated, the volume of the subsample should be selected so that the conditions of 9.1.1 apply.

8.3 Store the samples in conditions to minimize vapour loss and pressure build-up. Avoid storing the samples at temperatures in excess of 30 °C.

9 Sample handling
9.1 Petroleum products and fatty acid methyl esters
9.1.1 Subsampling. Cool in a cooling bath or freezer (6.5), or adjust the temperature of the sample and its container to at least 10 °C below the first selected test temperature before opening to remove the test portion. If an aliquot of the original sample is to be stored prior to testing, ensure that the container is still filled to at least 85 % of its capacity. Gently mix the subsample to ensure uniformity, so that the loss of volatile components and light ends is minimized.

NOTE Results of flash point tests may be affected if the sample volume falls below 85 % of the container capacity.

9.1.2 Samples that are liquid at ambient temperature. If sufficiently fluid, mix samples gently shaking by hand prior to the removal of the test portion, taking care to minimize the loss of volatile components. If the sample is too viscous at ambient temperatures, heat the sample in its container using a heating bath or oven (6.4) to a temperature not warmer than 10 °C below the test temperature, such that the sample can be mixed by gentle shaking.

9.1.3 Solid or semi-solid samples. If the material under test cannot be made sufficiently fluid to be introduced into the test cup through the orifice by heating in accordance with 9.1.2, transfer the test portion with a solids dispenser or spatula into the test cup whilst the cover is open.

9.2 Paints, varnishes and related materials
Prepare the samples in accordance with the procedures described in ISO 1513.