Some Tests and Equipment for Product Assessment

Moisture Content. Moisture content is determined by a standard procedure of drying to constant weight over and reporting the result as the percent loss in weight. 

Hygroscopicity. In this test a preweighed dry sample is held for 48 hr in 90% relative humidity at 30°C and the result reported as percent gain in weight of the dry sample. 

Bulk Density. Bulk density is determined by a method in which 1 g of lead azide is added incrementally to a vertical, graduated tube about 0.5 cm diam and partially filled with normal butyl alcohol. Particles adhering to the sides are washed down with butyl alcohol, addition of which is continued until the volume of material in the tube is exactly 5 ml. After standing 15 min without jarring or vibrating, the level of the lead azide column is read, calibration corrections applied, and the bulk density, calculated ftom the volume occupied, reported in g/ml. 

Purity. In this determination [7] the volume of gaseous nitrogen liberated by treatment of the lead azide with ceric ammonium nitrate is used to calculate the weight, reported as percentage, of lead azide in the test sample. 

Heavy Impact Sensitivity Test. The test results obtained are the minimum distances (in inches) through which a 2-kg hammer must fall to cause at least one sample to detonate in a series of trials with 10 test samples of approximately equal weight. 

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