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NTC thermistors are widely used as inrush-current limiters and temperature sensors, while PTC thermistors are used as self-resetting overcurrent protectors and self-regulating heating elements. An operational temperature range of a thermistor is dependent on the probe type and is typically between −100 and 300 °C (−148 and 572 °F).
Another type of thermometer that is not really used much in practice, but is important from a theoretical standpoint, is the gas thermometer. Other important devices for measuring temperature include: Thermocouples; Thermistors; Resistance temperature detector (RTD) Pyrometer; Langmuir probes (for electron temperature of a plasma) Infrared ...
Typically for thermistors used for chemical analysis the encapsulating medium is glass, although thermistors encapsulated in epoxy resin may be used in circumstances where either chemical attack (e.g., by acidic fluoride-containing solutions) or severe mechanical stress is anticipated.
NTC thermistors can be used as inrush-current limiting devices in power supply circuits when added in series with the circuit being protected. They present a higher resistance initially, which prevents large currents from flowing at turn-on. As current continues to flow, NTC thermistors heat up, allowing higher current flow during normal operation.
Thermostats have used bimetallic strips but digital thermistors have since become popular. Alcohol thermometers , infrared thermometers , mercury-in-glass thermometers, recording thermometers , thermistors , and Six's thermometers (maximum-minimum thermometer) are used in meteorology and climatology in various levels of the atmosphere and oceans.
An inrush current limiter is a device or devices combination used to limit inrush current. Passive resistive components such as resistors (with power dissipation drawback), or negative temperature coefficient (NTC) thermistors are simple options while the positive one (PTC) is used to limit max current afterward as the circuit has been operating (with cool-down time drawback on both).
Larger-diameter platinum wire is used, which drives up the cost and results in a lower resistance for the probe (typically 25.5 Ω). UPRTs have a wide temperature range (−200 °C to 1000 °C) and are approximately accurate to ±0.001 °C over the temperature range. UPRTs are only appropriate for laboratory use.
Thermocouple or thermistors sensors coupled with data loggers are now more often used to sense and record temperatures and record them in a digital format easily used by computers. They are widely available and come in a variety of types and varying probes.