From Measurement and Control Basics Fourth Edition

A pyrometer is any temperature-measuring device that includes a sensor
and a readout. However, in this section we will discuss only radiationtype
pyrometers. A radiation pyrometer is a noncontact temperature
sensor that infers the temperature of an object by detecting its naturally
emitted thermal radiation. An optical system collects the visible and infrared
energy from an object and focuses it on a detector, as shown in
Figure 7-21. The detector converts the collected energy into an electrical
signal to drive a temperature display or control unit.

Figure 7-21. Block diagram of radiation pyrometer

The detector receives the photon energy from the optical system and converts
it into an electrical signal. Two types of detectors are used: thermal
(thermopile) and photon (photomultiplier tubes). Photon detectors are
much faster than the thermopile type. This enables you to use the photon
type for measuring the temperature of small objects moving at high speed.

Radiation pyrometers are used to measure the temperature of very hot
objects without being in contact with them. Molten glass and molten metals
during smelting and forming operations are typical of the objects they
measure. In selecting the correct radiation pyrometer for an application
you must consider several factors. In either narrow or wide fields of view,...

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Products & Services
Pressure Sensors
Pressure sensors include all sensors, transducers and elements that produce an electrical signal proportional to pressure or changes in pressure.
Resistive Temperature Devices (RTD) Elements
Resistive temperature device (RTD) elements are wire windings or other thin-film serpentines that exhibit changes in resistance with changes in temperature. They are usually made of metallic elements or alloys such as copper, nickel, or nickel-iron.
Level Sensors
Level sensors are used to detect liquid or powder levels, or interfaces between liquids. There are two basic level-measurement types: continuous and point or multi-point.
Noncontact Infrared Temperature Sensors
Noncontact infrared temperature sensors absorb ambient infrared (IR) radiation given off by a heated surface. They are used in applications where direct temperature measurement is not possible.
Dial Thermometers
Dial thermometers are bimetal or bi-metallic, liquid or gas-filled, and vapor-tension-based. These devices display temperatures in Fahrenheit, Celsius, or both.

Topics of Interest

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