Importance

Loading Importance Indicators...

Abstract

A plurality of detector units are positioned to sense the refrigerated air temperature of a refrigerated air supply to a retail frozen food case or counter. The detector units are battery powered and supply a modulated radio frequency output reflecting the existence of a temperature condition integrated over time together with identification codes identifying a particular detector unit. A receiver unit receives the transmitted radio frequency signal, demodulates and decodes the signal, and supplies an output to an alarm unit. The alarm unit develops the alarm signal and supplies it to an indicator, as well as to an external alarm circuit which is a phone dialer which automatically dials a phone number in an external telephone system. In addition, the detector unit periodically generates an operational check signal which is also transmitted to and decoded by the receiver unit and supplied to the alarm unit. The alarm unit indicates the existence of the operational check signal. In the absence thereof, it causes generation of an alarm signal to be generated.

Loading the Abstract Image...

First Claim