A Simple Device for Integrating Temperature, Relative Humidity or Salinity over Time

Abstract

The robust diffusion sensor provides a simple, inexpensive, accurate method to integrate temperature, relative humidity (or water activity), or salinity for time periods up to several years. It does not require power or maintenance. Depending on temperature, precision of about 0.1°C for temperature and a few percent for relative humidity or salinity can be achieved. Various combinations of water-filled and desiccant-filled cells can be used for simultaneously integrating temperature, relative humidity or salinity by simply weighing the cells before and after exposure to the environment.