A Description of Thermocouple Pyrometers

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Thermocouple pyrometers - measure the output of a thermocouple (q.v.) placed in contact with the hot body; by proper calibration, this output yields temperature. Resistance thermometers - also called resistance temperature detectors (RTDs), are sensors used to measure temperature by correlating the resistance of the RTD element with temperature. Most RTD elements consist of a length of fine coiled wire wrapped around a ceramic or glass core. The element is usually quite fragile, so it is often placed inside a sheathed probe to protect it. The RTD element is made from a pure material whose resistance at various temperatures has been documented. The material has a predictable change in resistance as the temperature changes; it is this predictable change that is used to determine temperature. A liquid-in-glass thermometer - is the simplest and most commonly employed type of temperature measurement device. It is one of the oldest thermometers available in the industry. It gives fairly accurate results within the temperature range of -200 to 600°C. No special means are needed to measure temperature via these thermometers. One can read temperature readings easily with human eyes. They find their use in variety of applications such as medicine, metrology and industry. The foremost liquid-in-glass thermometer was introduced in the year 1650 in which the liquid filled in was spirit from wine. Later on, more linear thermometers were developed with the use of mercury as a liquid inside the thermometer. Bourdon tube thermometer - an instrument for measuring temperature, especially one having a graduated glass tube with a bulb containing a liquid, typically mercury or colored alcohol, that expands and rises in the tube as the temperature increases.

Radiation pyrometer - a pyrometer for estimating the temperature of distant sources of heat; radiation is focussed on a thermojunction connected in circuit with a galvanometer

An optical pyrometer - is a device which allows...
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