# NTC Thermistor Calculator

Many applications required high resistance which can be get by NTC Thermistor. For these applications resistance measurement is also important. Which can be done by NTC Thermistor Resistance Calcualtor.

For calculations of RC Time Constant please visit, RC Time Constant Calculator.

 Formula for calculating thermistor resistance is;Rnew=R0*exp-B*((1/273+Tref)-(1/273+Tnew))Please enter values of thermistor from datasheet. Beta Value of Thermistor: Resistance at Ref Temperature, Ω: Reference Temperature, Cᵒ: Target Temperature, Cᵒ:
 At Target Temperature Thermistor Resistance Value is;

Please, enter the value of Series Load Resistor and Input Supply Voltage.

Input Supply Voltage, Vsupply:
Series Load Resistor, R1 in Ω:
 Junction Voltage Values of Thermistor and Resistance is;

First refer below figure; we will calculate junction voltages Vout 1 and Vout 2, which is obtained because of change in respective resistance of NTC.

### What is an Thermistor?

The temperature sensing elements made up of semiconductor are called as Thermistor. Thermistors are made to exhibit vast changes in the resistance in proportion to little changes in the temperature.

Thermistor name is derived from the combination of the words thermal and resistor because thermistors are electrical resistors and are sensitive to the temperature.

### What is an NTC thermistor?

Full form of NTC is Negative Temperature Coefficient.

Non-linear resistors, which change their resistance characteristics with respect to the temperature are called NTC thermistor. The NTC resistance decreases with the increase in temperature.

### NTC Thermistor Resistance

Resistance values at mid of the temperatures within the range of the following temperature interval can be calculated by temperature coefficient α.

Where,

RT = Value of resistance at temperature T.
RTx = Value of resistance at the starting of the relevant temperature interval.
Tx = Temperature in °C at the starting of the relevant temperature interval.
T = Temperature of the interest in °C (Tx <T <Tx+1).
αx = Temperature coefficient at temperature Tx.

### Conclusion

Thermistors are used as temperature sensors. At room temperature thermistors have high resistance, and when dc voltage is applied, they produce heat energy and their resistance falls with respect to rise in temperature. Because of high resistance characteristic, thermistors are used for inrush current protection. NTC with high value resistance should be selected for inrush current protection. This measurement can be done by NTC Thermistor Resistance Calculator.