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 IR thermometer optris CTlaser 1M / 2M allows precise and quick measuring of high temperatures of metal surfaces. The short measuring wavelengths are not only capable of measuring metal temperatures but also allow for measurement of metal oxides and ceramics.
The robust premium stainless steel measuring head of the CTlaser pyrometer additionally offers exact marking of measuring spots in every distance due to its innovative double laser sight.
The infrared thermometer optris CTlaser 3M is perfectly suited for measurements of low metal temperatures and composite materials. It offers a temperature range between 50°C and 1,800°C and can be employed in up to 85°C without additional cooling.
Due to its extremely short response time of 1 ms, the highly efficient IR thermometer allows the surveillance of fast processes and measures reliably and precisely even on smallest measuring fields of up to 0.7 mm. Selectable outputs and various digital interfaces offer a high variability for the evaluation of the measured data.
The infrared thermometer optris CTlaser 4M with its wavelengths range of 2.2 – 6 μm is perfectly suited for measurements of metals, metal oxides, ceramics or materials with unknown or changing emissivity. It offers a temperature range between 0°C and 500°C and can be employed in up to 85°C without additional cooling.
Due to its ultra-fast exposure time of 90 μs, the highly efficient IR thermometer allows the surveillance of high speed processes and is the ideal pyrometer for low temperature applications. Selectable outputs and various digital interfaces offer a high variability for the evaluation of the measured data.
The infrared thermometer optris CTlaser 05M has been specifically designed for temperature measurement of metal surfaces and molten metals. It features a very short measuring wavelength of 525 nm, minimizing measuring errors during emissivity changes. The thermometer offers a temperature range between 1,000°C and 2,000°C.
The measuring head can be installed even in high ambient temperatures and can be equipped with industrial accessories for IR thermometers, e.g. water cooling, if necessary.
The infrared thermometer optris CTlaser LT allows for exact temperature measurement on smallest objects from 0,9 mm at a distance of 70 mm. The IR thermometer optris CTlaser LTF is due to its short configuration time of only 9 ms perfectly suited for surveillance of quick working processes.
Both models offer a robust and premium-quality stainless steel measuring head with an innovative double laser sighting for an exact measuring field marking in every distance.
The infrared thermometer optris CTlaser MT offers a special measuring wavelength for precise temperature measurement through flames of 200°C to 1,650°C. It is thus perfectly suited for surveillance of work pieces in ovens, for measurements in chemical reactors and for testing of refractory linings in kilns.
The stainless steel measuring head with its highly precise double laser visor allows for exact marking of measurement spots in any distance at any time. The temperature of even the smallest objects with a size of only 1.6 mm can be easily measured with the IR thermometer.
The infrared thermometer optris CTlaser P7 is perfectly suited for precise temperature measurement of thin plastic materials, e.g. PET, PU, PTFE, PA or CTA and for determination of temperatures of glass surfaces. It offers a broad temperature range from 0°C up to 710°C and can be employed in temperatures of up to 85°C without additional cooling.
The IR thermometer for measurements of plastic foils and glass temperatures is capable of targeting smallest objects of 1.6 mm in a distance of 70 mm. Its standardized two-wire interface additionally allows for a reliable transfer of measurement data and easy integration into a PLC.
The infrared laser thermometer optris CTlaser F2 offers a special measuring wavelength for temperature measurement of CO2 flame gases. This makes it optimally suited for e.g. combustion processes, garbage incineration, or processes in chemical reactors.
The IR thermometer’s temperature range covers temperatures from 200°C up to 1,650°C, while the stainless steel measuring head is heat-resistant up to 85°C without additional cooling. Optional cooling and protection equipment is available, ensuring exact temperature measurement even in rough surroundings.
The infrared thermometer optris CTlaser F6 is an upgraded version of the pyrometer optris CTlaser F2. It has also been designed for temperature measurement of CO flame gasses, e.g. in combustion processes, in garbage incineration, or in processes in chemical reactors.
The pyrometer measures temperatures precisely between 200°C and 1,650°C. Due to the measuring head being made of stainless steel, it is heat-resistant up to 85°C without additional cooling. Also, optional cooling and protection equipment is available, ensuring exact temperature measurement even in rough surroundings.
The infrared thermometer optris CTlaser G5 has been specifically designed for measurement of glass temperatures, especially for container glass, lightbulb production, vehicle glass production as well as in the manufacturing of solar cells. Last but not least, the IR thermometer optris CTlaser G5 allows for temperature measurement of smallest objects of 1 mm from a distance of 70 mm.
The IR thermometer optris CSlaser G5 HF offers very quick response times and is thus perfectly suited for fast processes.
The infrared thermometer optris CTlaser G7 is perfectly suited for precise temperature measurement of ultra-thin glass surfaces. It offers a broad temperature range from 100 °C up to 1200 °C and can be employed in temperatures of up to 85°C without additional cooling.
The IR thermometer for measurements of plastic foils and glass temperatures is capable of targeting smallest objects of 1.6 mm (0.06 in) in a distance of 70 mm (2.76 in). Its standardized two-wire interface additionally allows for a reliable transfer of measurement data and easy integration into a PLC.