Abstract: A security monitoring system includes a radio transmitter which transmits information by a radio signal and a processing apparatus which receives the information transmitted by the radio transmitter to give necessary processing depending upon the contents of the information. The radio transmitter has a testing signal transmission means for transmitting testing signals and a setting means for setting the transmission level in transmitting the testing signal to the lowest operating level to provide a simulated worst-case testing environment.

Abstract: An intrabox temperature display device converts a signal representing an intrabox air temperature detected by a molded temperature sensor placed in the intrabox of a refrigerator into a digital signal by means of an A/D converter. The intrabox temperature data detected having a succession of samples with given sampling periods is stored in a memory. The intrabox temperature data read out from the memory is averaged in an operation circuit. The averaged temperature data is displayed by a display section as the temperature data approximate to a real temperature for cooling or freezing foods in the refrigerator.