CHN weight percentages are accurate and reproducible to within ± 0.3%, for a very pure sample. Halogens, S and P weight percentage are accurate and reproducible to within ± 0.5%.

 

Microbalance

 

Accurate weighing of samples is a prerequisite for organic elemental analysis since results are presented on a weight percent basis. A microbalance is an instrument capable of making precise measurements of weight of objects of relatively small mass: of the order of a million parts of a gram.