Abstract: Apparatus and method for remotely measuring temperature in which a transmitter having a temperature sensitive element is placed in close proximity with the environment sought to the measured, with the temperature sensitive element controlling a reference voltage applied to a first terminal of a testing circuit, a second terminal of which receives a constant frequency alternating output of an oscillator. The output signal from the testing circuit is a constant frequency signal having a duty cycle which varies with the temperature of the element. An RF signal carrier is modulated at the transition points of the variable duty cycle signal for transmitting bursts of energy which are received and from which a replica signal corresponding to the variable duty cycle signal is reconstructed. A counter in the receiver counts high frequency pulses over a predetermined period of time during "on times" in duty cycle to obtain a numerical indication of the measured temperature.