Types of Infrared Sensors and their Features
The pyroelectric IR sensor uses a wavelength range from 2 to 14 µm. InfraTec uses special absorption layers so that the infrared sensors can even work as large-area, long-term stable receivers for UV radiation (e.g. 193 nm) but also for THz radiation in the range of 100 µm … 1 mm.
Further infrared sensors are Golay cells, bolometers and thermopiles, which also belong to the thermal IR sensors. The change in pressure of a gas volume is evaluated in a Golay cell and the change in temperature of a solid is evaluated in a bolometer. Thermopiles basically represent a series connection of thermocouples with an absorption layer and use the Seebeck effect. Photodiodes use the inner photo effect. At the same time, radiation quanta generate charge carrier pairs within a semiconductor. In the case of photoresistors, the radiation changes the electrical resistance.
Application of Infrared Sensors
Infrared sensors from InfraTec are used in gas warning devices, gas analysers, medical gas measurement technology, flame detectors and in contactless precision temperature measurement. These devices use the intensity measurement of infrared radiation in defined spectral ranges.
Use in Low and High Temperature Ranges
Depending on the basic physical principle, an IR sensor can work in a wide temperature range without cooling (so-called thermal infrared sensor) or must be cooled or at least thermally stabilized (semiconductor resistor or semiconductor diode) to achieve a good signal-to-noise ratio (detectivity).
A pyroelectric infrared sensor from InfraTec can basically work in the temperature range from - 55 to + 200 ° C. The pyroelectric sensor element made of lithium tantalate (LiTaO3) has a Curie temperature of over 600 ° C, which would also enable significantly higher operating temperatures. The temperature-limiting elements of a pyroelectric infrared sensor are the infrared window or infrared filter as well as integrated, extremely low-noise and low-leakage preamplifier technology.
InfraTec offers five different product groups including approximately 50 standard pyroelectric detectors. Choose your suitable infrared detectors with the help of our detailed detector search.