Abstract: A device is provided for sensing the condition of a pneumatic tire preferably of the type used on an automobile wherein the tire is mounted on a tire rim. The device comprises a housing, a band for mounting the housing to the tire rim, a sensor for monitoring the condition within the tire, circuitry operatively connected to the sensor for generating radio signals indicative of the tire condition, a power supply operatively connected to the circuitry, a centrifugal switch, and a receiver for receiving the radio signals. The centrifugal switch may be bypassed with the condition sensor switch to generate the radio signals when the pneumatic tire is stationary. Otherwise, the circuitry within the housing remains disabled until such time as the centrifugal switch senses a rotational frequency above a predetermined level. The circuitry is provided with a microcontroller operable between an active and a low power consumption mode wherein the battery comprising the power supply is conserved.