Understand NTC thermistor temperature sensor characteristics

The electrical characteristics of the NTC thermistor are combined to describe the resistance and temperature response of the thermistor sensor. Understanding this is very important for choosing the best thermistor sensor for given applications. The specifications of all TR series have the following characteristics:

Named resistance@25 ° C (ω)

● Provide a reference required to calculate the resistance at any other temperature within the temperature range of the computing sensor.
● Allows to select the correct sensor as a point matching or curve matching application.

Resistance temperature coefficient α, α (%/° C)

● Zero -power resistance phase on the rate of temperature change.
● Indicates the slope or sensitivity of the resistance and temperature response of the thermistor and the temperature response.

Various resistance (5%, 3%, 2%, 1%)

It is obtained by multiplying the given temperature by the resistance temperature coefficient.

Temperature tolerance (1.0 ° C, 0.5 ° C, 0.2 ° C, 0.1 ° C)

● Indicates the deviation of the RT curve (in the unit of degrees Celsius).
● Within a specific curve matching temperature range, the temperature difference is the same.
● Generally, the resistance of the resistance is specified with the heat -sensitive resistance.

Hot time constant (second)

When the step function of the temperature under zero -power conditions changes, the duration required for 63.2% of the difference between the initial temperature and the final body temperature of the thermistor is changed.

Temperature precision ((c)

Calculate the resistance to the resistance to the temperature coefficient (alpha). Given the same Alpha, better tolerance can produce better accuracy.

Maximum rated power (MW)

While maintaining the stability of its characteristics, the thermistor will consume a maximum power (in the units of millwathes) in a longer period of time.

Beta tolerance (1.0%)

Applicable to all TR series NTC thermistor sensors

Disposal constant (MW/° C)

Under a specific environmental temperature, the ratio of power consumption and body temperature changes in thermal resistance is represented by millwatter/degree Celsius.

Material constant beta, β (° K)

● The shape of the RT curve is the measurement value of a resistor at a temperature and resistance at another temperature.
● Use Beta equation to calculate and expressed it with Kaishi (° K).
● Beta equation requires two RT datasets, which is accurate enough for most industrial requirements.
● Unless otherwise explained, Beta is calculated using a temperature range from 25 ° C to 85 ° C.

Calculate resistance temperature
Steinhart-Hart (° K) or Beta (ß) equations can be used to calculate. Steinhart-Hart is more involved in the two, but it is more accurate because three RT datasets are required instead of two.