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Thermometer
Published in Hossam Fattah, LTE™ Cellular Narrowband Internet of Things (NB-IoT), 2021
There are two kinds of thermistors, NTC (negative temperature coefficient) and PTC (positive temperature coefficient). In NTC sensor, the resistance decreases with increasing temperature. PTC sensors are often used as resettable fuses. In PTC sensors, when there is an increase in temperature, it increases the resistance which means that less current is flowing in the resistor. As a result, as the resistor heats up, it limits the current flow and hence as a protecting circuit and fuse.
Measurement fundamentals and instrumentation
Published in Raymond F. Gardner, Introduction to Plant Automation and Controls, 2020
A thermistor is a type of resistor that exhibits large but predictable changes in resistance with respect to temperature. Typically, the thermistor is made from a semiconductor material such as a metallic oxide, ceramic, or a polymer, and can be obtained in positive (PTC) or negative (NTC) temperature coefficient versions. The resistance of PTC thermistors increases with temperature, like most metallic conductors, and they are not used for temperature measurement, but rather for current-limiting applications. NTC thermistors are used for temperature measurement, and NTC means that resistance decreases as the temperature increases, which is contrary to most conductors. Unlike the RTD, the thermistor temperature-and-resistance relationship is very non-linear, as shown in Figure 1.17 (left), and thus, they are somewhat limited to a measurement range near the knee of the curve. Thermistors are very accurate, typically within a half a degree Fahrenheit, and inexpensive, but they are limited to narrow temperature ranges, such as between the freezing and boiling points of water, as an example.
Fluid power measurement systems
Published in Ian C. Turner, Engineering Applications of Pneumatics and Hydraulics, 2020
The thermistor is an electrical resistor that exhibits significant changes in electrical resistance with changes in temperature. Two types of thermistor are produced: the PTC (positive temperature coefficient) thermistor in which an increase in temperature is accompanied by an increase in resistancethe NTC (negative temperature coefficient) thermistor in which an increase in temperature is accompanied by a decrease in resistance.The property of change of resistance with change of temperature is used for temperature measurement purposes, and a typical arrangement is to connect the thermistor device into one arm of a Wheatstone bridge with a suitable display or recording device. Figure 11.13 shows an arrangement.
Cerium-modified single perovskite CaMnO3: structural, dielectric, and transport properties
Published in Phase Transitions, 2023
Rajendra Meher, Rajib Padhee, S. K. Parida
Figure 9(a,b) displays the variation of resistance with temperature in the CaMn0.9Ce0.1O3 ceramic. It is observed that there is an exponential decrease of resistance with the rise in temperature, which confirms the NTCR character as discussed in the impedance study. The presence of Ce in the final product of the CaMn0.9Ce0.1O3 compound makes it a better candidate for thermistor applications. Therefore, CaMn0.9Ce0.1O3 can be used as a promising non-toxic thermistor application for various industrial applications. There are two types of thermistors, one is the positive temperature of coefficient (PTC) while the second is the negative temperature of coefficient (NTC). In PTC thermistors; resistance increases with the rise in temperature while resistance decreases with the rise of temperature in NTC thermistors.
A double perovskite BiLaCoMnO6: synthesis, microstructural, dielectric and optical properties
Published in Phase Transitions, 2023
S. K. Parida, Tanushree Satapathy, S. Mishra, R. N. P. Choudhary
Figure 14(a,b) discusses the variation of resistance with temperature in the BiLaCoMnO6 compound. The exponential decreasing resistance with the rise of temperature supports the NTCR character as discussed in the impedance study. The presence of La and Co in the final BiLaCoMnO6 compound makes it a better candidate for thermistor applications. Therefore, BiLaCoMnO6 may act as a promising non-toxic thermistor application for various industrial purposes. There are two types of thermistors, one is the positive temperature of coefficient (PTC) while the second is the negative temperature of coefficient (NTC). In PTC thermistors; resistance increases with the rise in temperature while resistance decreases with the rise of temperature in NTC thermistors.
Revived tungsten bronze ceramic for thermistor and RAM devices
Published in Phase Transitions, 2020
B. N. Parida, S. Behera, R. Padhee, Piyush R. Das
As per the earlier discussion, the resistance of the material is solely temperature dependent, so it is expected that the present sample can be used as thermistor. For this, resistance can follow Arrhenius behaviour as like as relaxation time and dc conductivity. Arrhenius relation resistance can be explained as per the following relation: where β represents the specific constant of the material and other notations have their respective parameters of the material. As discussed, resistance of the compound decreases with the rise in temperature which behaves as NTC thermistor [47]. For NTC thermistor can be determined by utilizing the following equation, where = Resistance at Temperature 1, = Resistance at Temperature 2.