C2, Range 0-10%, 12 g The Moisture Tester is ideal for determining the moisture in fine aggregates and granular materials, i.e. No. 4 sieve - soils, sand, clay, and powders – within seconds and in field conditions. No calculations are necessary, the FORNEY gauge provides direct reading of the chemical reaction between the reagent (calcium carbide) and water to produce acetelyne gas pressure.