What is a pyrometer?

  1. What is a pyrometer

A pyrometer is an instrument that is used to measure temperatures at a distance, they have a too wide temperature range, ranging from -40ºc to 4000ºc. It is primarily used to measure moving objects or substances, or in places where non-contact measurement is required. It is used, for example, to measure temperature in furnaces, incandescent metals, or gases.


How does it work?

Its operation depends on the type of pyrometer that is being used, but they are made up of several characteristics in common that make up its complete system:

  • They have a system that collects the energy emitted by the object.
  • A detector that converts this energy into an electrical signal.
  • A system that adjusts the emissivity to match the thermometer’s calibration to the object’s specific emission characteristics.
  • An ambient temperature compensation circuit that ensured that temperature variations within the sensor due to ambient conditions did not affect accuracy.

Modern microprocessor-based electronic systems allow complex algorithms to be used that provide linearization and real-time compensation of the detector output for greater precision of the measured object temperature.

Microprocessors can instantly display measurements of multiple variables (such as current temperature, minimum measured temperature, maximum measured temperature, average temperature, or temperature differences) on integrated LCD displays.


Types of pyrometer

There are 3 types depending on how they capture radiation from temperature.

Optical pyrometer

It is one that can measure the temperature of a substance from the radiation that emanates from your body, for which you do not need to be in contact with it. It works by comparing the brightness of the light emitted by the substance with that of a standard source. It is used both to measure the temperature of gases and incandescent bodies. In fact, it can measure temperatures above 1,000 ° C.

optical pyrometer

Radiation pyrometer

The radiation pyrometer captures the radiation emitted by the body whose temperature is to be determined. This type of pyrometer is based on the Stefan-Boltzman law. It is capable of measuring temperatures between 550 ° C and 1,600 ° C.


Resistance pyrometer

The resistance pyrometer is one that measures the temperature of the object or body through a thin wire that comes into contact with it. Heat produces the change in electrical resistance of the device, which makes a measurement of the object’s temperature from the heat.

resistance pyrometer