Thermocouple milliamp output

If two temperature readings from the same point in the process disagree, the chances are that a temperature indication is more accurate than a temperature-control signal. The temperature signal used for control has usually been converted from its direct milliamp output to operate a control station. The temperature indication is generated right from the junction of the thermocouple, and hence there is less chance for error. 

One of the most common safety trips is the automatic fuel-gas shutoff. We have this at home on our furnaces. We ignite the pilot light manually. The pilot light heats a thermocouple. The milliamp output from this thermocouple opens the fuel-gas valve to the main burner. The gas in the main burner is ignited from the pilot-light flame. Should the heat from the pilot light diminish below a certain point, the fuel gas to the main burner, as well as to the pilot light, will be shut off. 

Milliamp output The small (milliampere-range) electrical output from a thermocouple or pressure transducer that is used for control purposes. 

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