Pyrometer Series Metis MY80, MY81 and MY84 using pyroelectrical detectors and operating in a long wave band area between 8 and 14 µm. They were developed especially to measure small spot sizes at lower temperatures with fast exhibition times.
The pyrometer model Metis MY 84 is ideally suited to all types of applications like measurement of organic materials, painted metal surfaces, rubber, paper, textiles and thicker plastics.
Model Metis MY81 with spectral response between 8 und 10 µm can be used for similar applications like Metis MY 84. It offers however the advantage of using calcium fluoride as lens or window material which is easier to handle than the zinc sulphide material used for Metis MY84 ser. We recommend using this model also for all kind of applications where the Scanners SC10 SC11 or SC12 are necessary. The only disadvantage is the somewhat bigger spot size diameter at the same distance.
For none contact temperature measurement of thin polyester films and all kind of fluorocarbon-plastics the narrow band model Metis MY80 was developed. Further more it is best choice to measure thin glass surfaces in furnaces because glass is neither transparent nor reflective at 8,05 µm. It meets therefore the so called black body conditions of an ideal radiator.
The infrared energy radiated by the target is centered via focusable or fixed focus lenses directly on the detector. The focussing feature allows control of the cone of vision and offers the possibility to measure either a small spot (focused) or the average of a bigger spot (out of focus). Fixed focus lenses with larger diameter collect more infrared energy and therefore result in smaller spot sizes. The lenses are made of calcium fluoride CaF2 (MY80 and MY81) or zinc sulphide ZnS (MY84). If additional windows are necessary they must offer similar optical characteristics.
The detector is sensitive to infrared radiation in an area called the cone of vision. For the spot size diameter of the cone of vision at shortest, medium and widest focal distances, please see Chart 2, 3 and 4. For full scale temperatures up to 700°C the cone of vision diameter in front of the lens is about 16 mm and about 8 mm for full scale temperature of 1000°C. This area has to be kept free from any intervening objects. The spot size diameter for distances not given in the chart can be calculated by interpolation.
Each temperature range of MY81 and MY84 are available as well with different fast exposition times of 5, 30, or 100 ms. Slower models offer better optical resolution (smaller spot size). To achieve effectively the best optical resolution of 170:1, with 100 ms exhibition time, the Metis MY81 can be supplied with fixed focus lenses also. For the spot size diameter of the 3 different fixed focus lenses available with MY81 ser.