Thermoelectric devices thermometers

Early bolometers used, as thermometers, thermopiles, based on the thermoelectric effect (see Section 9.4) or Golay cells in which the heat absorbed in a thin metal film is transferred to a small volume of gas the resulting pressure increase moves a mirror in an optical amplifier. A historical review of the development of radiation detectors until 1994 can be found in ref. [59,60], The modern history of infrared bolometers starts with the introduction of the carbon resistor, as both bolometer sensor and absorber, by Boyle and Rogers [12], The device had a number of advantages over the Golay cell such as low cost, simplicity and relatively low heat capacity at low temperatures. 

Thermocouples have been used extensively in cryoscopy and the use of these devices for determining temperature difference is well documented. Their advantages over platinum resistance thermometers are flexibility and small size. They can be even smaller than thermistors. Unlike resistance thermometers, they do not dissipate heat when in use. The temperature-e.m.f. relationship is more stable than with thermistors. The copper-constantan couple has been used extensively because it has a relatively high thermoelectric power and the temperature-e.m.f. characteristics are particularly linear and stable. 

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