NTCs feature linear output

The BetaLinear Series of devices maintain the advantages of the NTC thermistor (high sensitivity, small size and interchangeability) while offering a linear signal output.

The principal benefit of NTC thermistors is the high levels of sensitivity offered compared other sensor types (typically -3 to -6% change in resistance per degree centigrade).

However, the relationship between resistance and temperature is nonlinear.

This nonlinearity is not an issue in sensing applications where there is computing power available to use a mathematical model to relate the resistance of the NTC thermistor to its temperature.

In certain temperature-sensing applications however, a linear response (of voltage or resistance) against temperature is desirable.

In simple terms, a linear output makes it easier in terms of accommodating existing instrumentation and minimising computational software requirements.

The BetaLinear Series of devices maintain the advantages of the NTC thermistor (high sensitivity, small size and interchangeability) while offering a linear signal output.

The BetaLinear Series devices combine precision resistors and thermistors, which in combination generate a linear response to temperature.

The linear composite typically consists of two or three sensor elements; the most popular being (36K53A1) which uses two thermistor elements (30K5 and 6K3) and appropriate resistors which give a linear output in the range 0-100C.

The circuit designs can accommodate a wide variety of circuit mounting options.

These include custom probes assemblies for the thermistor sensing elements and mounting precision resistors at board level in a control module.

It is also possible to package the thermistors and resistors which form the linearisation circuit in a single probe construction.

These linear thermistor networks are ideally suited for temperatures measurement and control in the range from -30 to +100C.

They are easily interfaced to both analogue and digital circuitry.

The BetaLinear Series can be configured in either resistance or voltage mode where they can provide up to 10 times the voltage output of a thermocouple sensor.

Thermistor accuracy, depending on construction, is +/-0.3C from 0 to 70C.

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