is the conversion of a liquid into a vapor; also, a test procedure that yields data on the volatility of a petroleum product. Evaporation testing of solvents may be performed in accordance with the Federation of Societies for Paint Technology Method II. In this method, a small sample of product is applied by hypodermic syringe to a filter paper on a sensitive spring balance, then allowed to evaporate under controlled conditions of temperature, relative humidity, air movement, etc. The loss of sample weight is plotted with respect to time.

Also see distillation test.