MICROWAVE SENSOR, AND ELECTRIC FIELD GENERATOR FOR SELF- DIAGNOSING SENSOR

摘要

PROBLEM TO BE SOLVED: To provide a constitution capable of conducting surely an self-diagnosis operation periodically, as to self-diagnosis for a microwave sensor. SOLUTION: The microwave sensor 3 is provided with an electric field generating circuit 9 for self-diagnosis. One portion of a lead wire L of the circuit 9 is positioned in the vicinity of an antenna 31. A switch 93 of the circuit 9 is closed to generate an electric field for the self-diagnosis in the periphery of the antenna 31. Whether a signal affected by the electric field is output as an output of an IF amplifier 34 or not is determined by a determination part 95 to diagnose the microwave sensor 3.