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 aluminum casting to operate in harsh industrial environments. A large variety of Protective hardware and mounting assemblies are available for harsh industrial environments.
Pyrometer Series Metis MS with silicon and Metis MI with indium gallium arsenide detector operate at the near end of the infrared spectrum. 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.
Lenses and Fibre-Optic Cable
The infrared energy radiated by the target is centered either directly on the detector (standard version) or on one end of a fibre optic cable by focusable lenses. This feature offers the possibility to measure a small spot (focused) or the average of a bigger spot (out of focus). Lenses are made ofBK7, an optical glass which is highly transparent in the spectral region of Metis MS and MI. If additional windows are necessary, they must offer similar optical characteristics. Fibre-optic versions are supplied with 2.5 m long single mode fibres, diameter 0.2 mm, (0.4 mm MI18 only). Longer cables are available on request.
Metis MS and MI Standard Pyrometers are 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 units, with full scale temperatures above 1800°C, is equipped with a dimmable sight attenuation filter to protect the eye. And finally, the third solution is a build in b/w video camera for all applications where neither the laser nor the sight through version can be used. This feature offers also possibilities for remote controlling of the heating process in dangerous environments. The fibre-optic version of Metis can be equipped with laser pointer only.
The pyrometer can be equipped with PID control output signal instead of the analog temperature output signal 0 – or 4 – 20 mA. The control features and functions can be operated manually by PC or automatically by digital commands. The self-optimizing feature automatically determines the P, I and D control parameters. If PID option is chosen, the temperature information will be available from the pyrometer only via digital interface.
For measuring and holding of the highest instantaneous temperature value a peak picker (maximum value storage) is installed to compensate interruptions or attenuations in radiation caused by bursts of steam, smoke or dust. It can be either reset automatically or manually by an external contact closure or periodically by user preset clear time. In this last case the highest temperature will be held in a dual storage and will be reset in only one of the two storages after preset clear time to avoid a decrease of the temperature output, should a short cold period appear just at the reset moment. The exposition time is the length of time it takes for the output signal to reach 90% of a step change in measured temperature. It can be used to filter out rapid variations in temperature and achieve a “more quiet” signal for control or display purposes.
The PSCWin Software is available for automatic or manual set up of the pyrometer, for recording and for saving of graphical or table files. At the same time these files can be used for quality assurance purposes because the parameter settings are recorded, too. Minimum computer requirements are: 500 MHz clock frequency and Windows 95, 98, ME or XP operating system.
In order to measure temperatures at the strip bottom in hot rolling mills, or slab temperatures inside the cooling chamber of continuous casters, special rugged sensing heads in stainless steel housings with external electronic boards have proven themselves very well for this purpose.