With the introduction of specialty aluminum alloys designed for applications such as aerospace, automotive or safety products, there is an increasing need to produce products with complex mechanical specifications and to reduce product weight. In order to meet the stringent requirements of the product, the temperature of the extrusion quenching process is very important and needs to be monitored accurately and continuously. This continuous temperature monitoring improves process and product quality. In addition, extrusion plants that produce low-quality profiles can increase their extrusion speed and productivity.

Laser pyrometers receive invisible infrared energy emitted by various objects. Infrared radiation is part of the electromagnetic spectrum, which includes radio waves, microwaves, visible light, ultraviolet light, R-rays, and X-rays. Infrared is between visible light and radio waves. Infrared wavelengths are usually expressed in microns, with wavelengths ranging from 0.7 microns to 1000 microns. In fact, the 0.7 micron to 14 micron band is used for infrared thermometers.
The undisputed understanding of infrared technology and its principles is its temperature measurement. When measuring temperature with a laser pyrometer, the infrared energy emitted by the measured object is converted into an electrical signal on the detector through the optical system of the infrared pyrometer. Displaying the temperature reading of the signal, there are several important factors that determine the temperature measurement. Important factors are emissivity, field of view, distance to spot and spot location. Emissivity, all objects reflect, transmit and emit energy, and only the energy emitted can indicate the temperature of an object. When an infrared thermometer measures surface temperature, the instrument can receive all three types of energy.