Various application of parsing the thermistor

Thermistor is a thermistor, described its resistance depends on the outside temperature. Temperature measurement and control is the main application of thermistor. The thermistor is used for the below explain in detail a variety of other applications.

1。

thermal resistance temperature measurement is a resistor, the subtle change of resistance with temperature changes. Thermistor has good sensitivity, can provide high precision and high resolution. Industrial thermistor at 25 degrees Celsius temperature with 2000 ohm resistance, temperature coefficient is 3. 9%.

thermistor circuit consider thermistor and ammeter and batteries in series, as shown in the figure below. Tiny changes cause the resistance of the thermistor temperature changes, the relatively change current of the circuit. Micron for temperature calibration. Micron resolution of about 1 & ordm; C。

the temperature control circuit using a bridge circuit, the thermistor is more sensitive, shown above, and provide the accurate measurement. Standard bridge circuit in 25 & ordm; The voltage is about 18 C/mv & ordm; C, the circuit USES 4 k & Omega; Thermistors.

2。

simple temperature control the temperature of the circuit as shown in the figure below. The circuit is used with AC excitation bridge series 4 k & Omega; Resistance. Applied to the unbalanced voltage and the output of the amplifier relay. Relay control circuit current and generate heat. The accuracy of the circuit control at 0. 00005º C。

themristor -

temperature control circuit controlled by the thermistor circuit stable and sensitive. Very fast response time of control circuit of thermistor, circuit is simple.

3。 Temperature compensation

temperature has a negative temperature coefficient, and the conductor and semiconductor has the positive temperature coefficient. For this reason, in the circuit using a thermistor to compensate the temperature of the components and circuit.

disc thermistor is used to compensate temperature does not exceed 125 & ordm; C。 Thermistor installed near the circuit components, such as copper sheet coil, it experiences the same as the circuit of temperature change. The curve shows the compensation network.

thermistor figure

compensating network includes a thermistor with thermal resistor in parallel. The negative temperature coefficient of thermal resistor and positive temperature coefficient circuit components to keep the whole circuit temperature constant.

4。 Other applications

thermistor has a variety of other applications.

it is used for measuring the high frequency power.

thermistor measuring thermal conductivity.

thermistor measuring the pressure of the liquid.

it is measuring the composition of the gas.

thermistor vacuum and provides the time delay measurement.

compared with thermocouple and resistance thermocouple, thermal resistance has more application.