"Serial" paint testing personnel, I would like to say to you (2) - non-volatile content determination, you did the right thing?

non-volatile content, which is defined as the mass fraction of the residue obtained by the sample by volatile under the prescribed test conditionsThe non-volatile content of the sample is not an absolute amount, the value depends on the measurement of the sample's weighing, the heating temperature and time used and other factorsat present, coatings and related products commonly used in the national standard method is GB / T1725-2007 color paint, varnish and plastic non-volatile content determinationthe test process of common errors are:, the test sample was not fully stirred before sampling
the sample is not evenly stirred, the sample mentioned as taken is not representative, especially for some easy to layer, precipitation of paint products, such as zinc-rich primer, cloud iron paint, this operation will result in a large deviation in the test results, test results can not be reproducedsaid that when taking samples with glass rods or wooden sticks and other spouts into the test dish
this operation can not ensure that the sample is evenly distributed, especially for color paint samples containing color fillers, for volatile samples, no weight reduction method is taken to claim the sample
if the direct weighing method is used to call the volatile sample, the weighing process due to solvent volatilization will lead to inaccurate sample values, resulting in a large deviation in the test resultssaid that after taking the sample did not fully spread the sample in the test flat dish
the inside of the sample during the baking process containing solventised is not easy to wave, this action will result in high test resultserror diagram
the above operation is correct:, the test sample is fully stirred evenly immediately called the samplethe sample is called when taking the sample with a spoon (or can ensure that the uniform sample of the apparatus) sampling into the test dish, the volatile sample stirred evenly into the small drop bottle, with the reduction of the amount The method claims to take the sample , said that after taking the sample, the sample is completely or as far as possible spread in the test flat dish
for high viscosity samples or easy-to-skin samples, using a wire (can be coated with unpainted paperclips) and dish together to weigh the sample When the test accuracy requirements are high, the viscous sample can also be diluted and dispersed with a small amount of thinner the correct picture
did you do the right thing? relevant wonderful article (click on the title to read) "serial" paint detector, I would like to say to you (1) - from the experimental auxiliary staff W wipe window sill caused by the feeling "guide" paint detector, I would like to say to you (3) - "fine" to operate, reading "degree", how can you do a good job of paint "fineness" test?