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Internals of a pyroelectric sensor. Pyroelectricity (from Greek: pyr (πυρ), "fire" and electricity) is a property of certain crystals which are naturally electrically polarized and as a result contain large electric fields. [1] Pyroelectricity can be described as the ability of certain materials to generate a temporary voltage when they are ...
In terms of the pyroelectric detector, it can be used as a sensor to support the system. Due to the unipolar axis characteristics of the pyroelectric crystal, it is characterized by asymmetry. Polarization due to changes in temperature, the so-called pyroelectric effect, is currently widely used in sensor technology.
Pyroelectricity – the creation of an electric polarization in a crystal after heating/cooling, an effect distinct from thermoelectricity; Thermionic emission – the liberation of charged particles from a hot electrode; Thermogalvanic cell – the production of electrical power from a galvanic cell with electrodes at different temperatures ...
Being pyroelectric, this material develops a voltage difference across two of its faces under changing temperature conditions; consequently, lead zirconate titanate can be used as a heat sensor. [5] Lead zirconate titanate is also ferroelectric , which means that it has a spontaneous electric polarization ( electric dipole ) that can be ...
Golay cells follow thermal expansion. In IR spectrometers the pyroelectric detectors are the most widespread. The response time and sensitivity of photonic detectors can be much higher, but usually these have to be cooled to cut thermal noise. The materials in these are semiconductors with narrow band gaps. Incident IR photons can cause ...
Ferroelectric polymers, such as polyvinylidene fluoride and poly[(vinylidenefluoride-co-trifluoroethylene], are very attractive for many applications because they exhibit good piezoelectric and pyroelectric responses and low acoustic impedance, which matches water and human skin. More importantly, they can be tailored to meet various requirements.
Thermopile laser sensors find their use mainly where sensitivity to a wide spectral range is needed or where high laser powers need to be measured. Thermopile sensors are integrated into laser systems and laser sources and are used for sporadic as well as continuous monitoring of laser power, e.g. in feedback control loops.
It is a grid of vanadium oxide or amorphous silicon heat sensors atop a corresponding grid of silicon. Infrared radiation from a specific range of wavelengths strikes the vanadium oxide or amorphous silicon, and changes its electrical resistance. This resistance change is measured and processed into temperatures which can be represented ...