Pyrometer Series Metis MQ utilizes lead sulphide and Metis MB lead selenide detectors with filtered spectral response at relative short infrared wavelengths, and they are therefore often used to measure metal surfaces above 75°C (Metis MQ) or above 50° (Metis MB).
The emissivity of these surfaces decreases with an increase wavelength, so they offer much better performance than other pyrometers with similar low zero scale temperatures, but with longer wavelength response.
Other major advantages are the lower sensitivity for changes in emissivity at shorter wavelengths, the small spot sizes, the fast response time and the digital signal processing which allow the pyrometer to operate within very wide temperature ranges.
This makes these units preferable for many other applications, too. Optical and electronic parts are housed in a rugged IP65, extruded aluminium casting to operate in harsh industrial environments.
- Self-Contained, Stand Alone Operation
- Wide Temperature Range Selections from 300 to 3500°C (572 to 6332°F)
- Through Lens Sighting, Laser Aiming, or Video
- Superior Optical Resolution ( FOV 250:1)
- Variable Focus Optics For Quick Adjustment
- Fast Response - 2 milliseconds, adjustable
- Simultaneous Analog and Digital Outputs
- Bi-Directional Digital Communications
- Durable IP65 Rated Housing
- Innovative, Rugged Designed Accessories
Two-Color or Ratio Pyrometers measure temperatures from the ratio of radiation signals of two adjacent wavelengths as opposed to measuring the absolute intensity within one wavelength, i.e. 1-color pyrometers. The advantages and benefits of using 2-color sensors are the following:
- Automatic compensation for viewing though dirty windows, dust and partial smoke between sensor and target.
- Compensation for changes in target emissivity i.e. gray bodies—targets with the same emissivity on both wavelengths.
- Measures smaller target than sensor’s fi eld of view (FOV) i.e. measures weighted peak temperature within FOV.
- Unaffected by moving targets within FOV.
- Induction Heating
- Steel / Metals
- Heat Treating and Annealing
- Vacuum Furnaces
- Research and Development
Metis 2-Color Non-contact Infrared Thermometers have universal applications and can also be switched and operated in a 1-Color or single wavelength mode. In 1-Color mode, operators have the choice of deriving the analog output signal from the shorter or longer wavelength or both. Using digital communication, these temperature measurement results can be recorded and compared to quickly determine whether the target is a “gray body“ radiator or not. Utilizing Process Sensors’ Plug & Play box, the MQ Series can be remotely configured, provide temperature indication, profile trend screen, alarm relays and an assortment of analog and digital outputs, as well as providing a quick disconnect from the sensor to the box.
The detector is sensitive to infrared radiation in an area called the Cone of Vision. For the spot size diameter of this area at the shortest, medium and longest distances, when in focus, please refer to Table 2. The cone of vision diameter (aperture) at the lens is 17 mm (full scale temperature < 1400°C) and 8 mm for temperature ranges above 1400°C (2552°F). The spot size diameter for distances not given in the table can be calculated by interpolation.
Fiber-Optic Cable and Lenses
The infrared energy radiated by a target is collimated via the focusable lens either directly onto the Metis detector (standard version) or onto one end of a fiber optic cable. For installations with limited space, there is an adjustable focus miniature lens version. The adjustable focus feature offers the advantage of measuring the smallest spot (focused) or the average temperature of a bigger spot (out of focus) at a user defined distance.
The MQ Series lens is BK7 (crown glass). If additional viewing windows are used, they must exhibit good optical transmission characteristics at less than 2 microns. The spot size of the focusable lenses for use with the Metis MQ Fiber Optic Versions can be taken from Tables 3 and 4. The cone of vision diameter (lens aperture) indicated for Table 3 lenses is 18 mm, and 7 mm in general for Table 4 lenses. The larger lens assembly OQ25-BO with a diameter of 25 mm provides a smaller spot size and wider focus range than the miniature lens version. Fiber optic versions are equipped with a standard 2.5 m, single mode fiber optic cable, having a core diameter of 0.2 mm, (0.4 mm core for 300 to 1000°C only). Longer cables lengths are available up to 30 meters based on selected temperature ranges.