About the Honeywell Q340A1108 30 MV Thermocouple with Male Connector
Honeywell Q340A1108 30 MV Thermocouple with Male Connector. The Q340A thermocouples sense the pilot flame on gas-fired heating systems. The pilot flame heats the tip of the thermocouple, producing a temperature differential between it and the base to generate a small amount of DC power, measured in millivolts.