Apparatus for measuring the temperature of an operating spark plug

摘要

Apparatus for measuring the temperature of the insulator tip of a spark plug being operated in an internal combustion engine. A thermocouple is embedded in the surface of the insulator tip adjacent the spark gap for sensing temperature. The output of the thermocouple is connected through an electro-optical ignition voltage isolation circuit to circuitry which maintains a substantially constant temperature signal during the time interval that ignition voltage is applied to fire the spark plug. The temperature signal may drive a temperature indicating display or devices such as chart or tape recorders to produce records which may be used in analyzing either operation of the spark plug or combustion.