Precision Test [1]

A term used to describe certain types of tightness tests conducted on underground tank-and-piping systems.

To qualify as a precision test a tightness test must take into account several variables, particularly product temperature at differing liquid depths and tank-end deflection.

The term, precision test, was originally used in Underground Leakage of Flammable and Combustible Liquids, NFPA 329, a publication of the National Fire Protection Association [2]. In its current edition, however, the publication has dropped use of the term. Even so, some tank regulations continue to require that tank testing be accomplished through "precision test" methods.