MOISTURE SENSOR

摘要

A moisture sensor is disclosed which measures cumulative exposure to moisture. The moisture sensor comprises a matrix having a hygroscopic material, a first reagent, and a second reagent which interact only in the presence of water to produce a detectable, irreversible change in the matrix to provide a moisture indication. The moisture sensor may be incorporated with a disposable diagnostic device, whereby a method for preventing the use of such a disposable diagnostic device if exposed to excessive cumulative humidity is also disclosed.