Knowing the exact value of the radiation temperature is essential for the calibration process. It can be measured by either using a contact thermometer (in combination with the determination of the emissivity) or a transfer standard infrared thermometer. This value can then be used to determine the device constant for an initial calibration of the infrared sensors. In order to conduct a post-calibration by customers or local calibration facilities, the calibration temperature should be near the temperatures which occur at the respective applications.
Optris makes use of a transfer standard radiation thermometer CTlaser-PTB (see figure) to measure the radiation temperature of a reference source. The CTlaser- PTB is based on the IR thermometer optris CTlaser. The CTlaser-PTB needs to be traceable to the international temperature scale from 1990 (ITS-90). Thus, it is calibrated by the PTB (German national metrology institute) on a regular basis. ITS-90 is a very good approximation of thermodynamic temperature. It is based on 17 well-reproducible fixed values such as melting points of highly pure metals. Within the framework of ITS-90 the CTlaser-PTB is compared to national temperature standards from the PTB. This comparison within a closed chain of comparative measurements with a known uncertainty in measurement takes place on a regular basis.
Based on the CTlaser-PTB, Optris produces the CTlaser- DCI as a high-precision reference IR thermometer for its customers. The DCI units are produced with pre-selected components supporting high stability of measurement. In combination with a dedicated calibration at several calibration points the CTlaser-DCI achieves a higher accuracy than units from series production.
The optics of an IR thermometer is described by the distance-to-spot-ratio (D:S). Depending on the quality of the optics a certain amount of radiation is also received from sources outside the specified measurement spot. The maximum value here equals the radiation emitted by a hemispheric radiant source. The respective signal change in correlation with a resize of the radiation source is described by the Size-of-source effect (SSE).
As a result of this correlation all manufacturers of IR thermometers use accurately defined geometries for the calibration of their units; meaning depending on the aperture of the radiation source (A) a distance (a) between the IR thermometer and the reference source is defined. Thus, the value specified in datasheets and technical documentation as a measurement field is, in general, a certain defined percentage of this radiation maximum – values of 90 % or 95 % are common.
The Optris PI 450i G7/ PI 640 G7 infrared cameras are the first industry-specific thermal imaging cameras in the PI series. Designed specially for the glass industry, this camera measures in only one spectral range.
The IR camera is used as a line-scan camera in the field of sheet glass production and offers various possibilities for documenting and controlling the process.
This compact, high-performance infra-red camera for the glass industry is available with interchangeable lenses and industrial accessories. The comprehensive license-free software package “Optris PIX Connect” is included in the price.
The infrared cameras optris PI 400i / PI 450i are the smallest thermographic cameras in their class. Being equipped with a measurement speed of 80 Hz and an optical resolution of 382 x 288 pixels they provide real-time thermographic images in high speed.
The IR camera PI 450i is, due to its thermal sensitivity of 40 mK, specifically suited for the detection of slightest temperature differences, making it indispensable in quality control of products and in medical prevention.
The compact and high-performance infrared cameras offer a temperature range of -20°C up to 900°C, being optionally upgradeable up to 1500 °C. They can be delivered with exchangeable optics, industrial thermal imager equipment and they come with an extensive license-free thermography software package.
The thermal imager optris PI 640i is the smallest measuring VGA infrared camera worldwide. With an optical resolution of 640x480 pixels, the PI 640i delivers pin-sharp radiometric pictures and videos in real time.
With a body sized 45x56x90 mm and weighing only 269 - 340 g (depending on lens), the optris PI 640i counts among the most compact thermal imaging cameras on the market.
It can be delivered with industrial thermal imager equipment and it comes with an extensive license-free thermography software package.
he optris PI NetBox is a miniature PC for the PI series of infrared cameras. It upgrades the optris PI IR Camera series to stand-alone solutions or acts as USB to Ethernet adapter. This permits to implement longer distances between the process proper (PI camera) and the process monitoring system (PC).
Long-distance control of infrared cameras: Acting as a USB to Ethernet adapter, the USB Server Gigabit 2.0 allows bridging distances significantly longer than 20 meters between the PC and a PI thermal imaging camera or a Xi 400 infrared camera and the optris CTvideo/ CSvideo video pyrometer series.
Our newly developed industrial process interface (PIF) permits automatic process monitoring, for the continuous in-operation control of the hardware of the infrared cameras with all cable connections and the free analysis software PIX Connect. An innovation on the market in this monitoring process is the control of the external computer.
With the new glass inspection system, temperature differences during glass hardening processes can be quickly detected, thus avoiding rejects and providing automatic quality monitoring.
The Top Down GIS 640 R system with temperature referencing by means of a sensor from below as well as automatic emissivity correction for standard and low-E glasses was specially developed for process control in glass tempering machines.
The newly developed thermal camera optris PI 1M is especially suited for temperature measurements of metals, as these exhibit a distinctly higher emissivity at the short measurement wavelength of 1μm than at measurements in the previously conventional wavelength range of 8-14 μm.
In parallel with the visualization of a thermal process, the high-performance sensor electronics allow a short reaction time of 1ms for the displaying of the temperature information of the center pixel.
The spectral range of 500 to 540 nm of the newly developed thermal imager optris PI 05M decreases measurement errors resulting from unknown or changing emissivities. Due to the spectral range as well as the continous measurement range from 900 to 2450 °C, the compact infrared camera is perfectly suited for temperature measurements of molten metals.
The frame rate of 1 kHz as well as the high optical resolution enable an optimal adaption to the respective application.
The spectral range of 800 nm of the newly developed thermal imager optris PI 08M decreases measurement errors resulting from unknown or changing emissivities. Due to the spectral range as well as the continous measurement range from 575 °C to 1900 °C , the compact infrared camera is ideal suited for for almost all NIR and CO2 laser processing applications.
The newly developed Microscope lenses are especially designed for thermal inspection of electronic boards and analyses of small chip level components down to 28 μm. The distance between the measurement object and the camera can vary between 80 and 100 mm.