The Model CT485B is a completely self-contained temperature / relative humidity recorder. It is microprocessor based to accurately measure, indicate and record temperature and relative humidity. This rugged unit comes standard with alarms. They contain a single, integral relay contact which closes in response to an alarm condition. Simultaneous high and low alarm points for temperature and relative humidity are user selectable. When the current conditions exceed any of the preset values, the 2 Amp relay contact closes and an audible alarm sounds.