Pyrometer Series Metis M18 with indium gallium arsenide detector operates at the near end of the infrared spectrum (1.8u). They are an excellent choice for measurement of ferrous and non-ferrous metals above 120°C because the emissivity of un-oxidized metal surfaces is higher at shorter wavelengths. Other major advantages are the lower sensitivity for changes in emissivity at shorter wavelengths, the small spot sizes, the fast exposition time and the digital signal processing which allow the pyrometer to operate over very wide temperature ranges. This makes these units preferable for other applications, too. Optical and electronic parts are housed in rugged IP65 extruded aluminium casting to operate in harsh industrial environments. A large variety of Protective hardware and mounting assemblies are available for harsh industrial environments.
Lenses and Fiber Optic Cable: The infrared energy radiated by the target is centered either directly on the detector (standard version) or on one end of a fiber optic cable via the focusable lens. This feature offers the possibility to measure a small spot (focused) or the average of a bigger spot (out of focus). Lenses are made of BK7, an optical glass which is highly transparent in the spectral region of Metis MI18. If additional windows are necessary, they must offer similar optical characteristics. Fiber optic versions are supplied with a 2.5 m long single mode fiber, diameter 0.2 mm, (0.4 mm MI18 only). Longer cables are available on request.
Optical Alignment: The standard Metis MI18 Pyrometer series is available with 3 different solutions for aiming the sensor onto the target. Number one and most popular method is the built in laser pointer which is also helpful for focusing. Number two is a sight through optics version with reticle-defined target which is advantageous for applications where aiming onto hot, incandescent targets is needed. The viewing telescope of these sensors with full scale temperatures above 1800°C, is equipped with a dimmable light attenuation filter to protect the eye. And finally, the third solution is a built-in color video camera for all applications where neither the laser nor the sight through version is desired. This feature offers also possibilities for remote controlling of the heating process in dangerous environments. The fiber optic version of Metis can be equipped with a laser pointer only.