A thermopile consists of multiple thermocouples wired in series to multiply the small voltage generated by a temperature difference. They are commonly used in non-contact infrared thermometers, gas burner safety valves, and heat flux sensors. By stacking the junctions, the device produces a much larger, more measurable output signal than a single thermocouple could achieve.
Heard on the job
The pilot light heats the thermopile enough to hold the main gas valve open.
Insider tip
A thermopile generates voltage from a temperature gradient, whereas a thermistor changes its electrical resistance based on absolute temperature.