BAPI Thermistors Overview

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BAPI THERMISTORS OVERVIEW

Thermistor Description

BAPI Thermistors are thermally sensitive resistors known for exhibiting a large change in resistance with only a small change in temperature. It is important to note that a thermistor’s change in resistance is non-linear. It follows a pre-defined curve which is provided by the thermistor manufacturer. An example of a thermistor output curve can be seen in Figure 1.
Thermistors are manufactured to follow a specific curve with a high degree of accuracy. All BAPI thermistors have a standard accuracy of ± 0.2 °C throughout the commercial temperature range of 0 to 70 °C. BAPI also has available a higher accuracy sensor for meeting tougher specs. The extra precision (XP) line has an initial accuracy of ± 0.1 °C throughout the commercial temperature range of 0 to 70 °C. Please call for availability and pricing on XP line thermistors. Both accuracy levels allow BAPI thermistors to be interchanged without incurring the extra expense of offsetting the controller.

Thermistor Specifications
Interchangeability Tolerance (Accuracy): ± 0.2 °C (0 to 70 °C) Standard ± 0.1 °C (0 to 70 °C) XP Option Dissipation Constant: 2.7 mW/°C Stability (drift): Less than 0.02 °C / year
Sensor Type	Reference Resistance	Operating Range
1.8K	1.8K Ohms @ 25 °C	-55 to 150 °C
3K	3K Ohms @ 25 °C	-55 to 150 °C
3.3K	3.3K Ohms @ 25 °C	-55 to 150 °C
10K-2	10K Ohms @ 25 °C	-55 to 150 °C
10K-3	10K Ohms @ 25 °C	-80 to 150 °C
10K-3(11K)	5.2K Ohms @ 25 °C	-80 to 150 °C
20K	20K Ohms @ 25 °C	-80 to 150 °C
50K	50K Ohms @ 25 °C	-80 to 150 °C
100K	100K Ohms @ 25 °C	-80 to 150 °C

Thermistor Specifications

Definition of Specification Terms

Interchangeability Tolerance (Accuracy)
The maximum amount that thermistors following the same curve will differ from each other.

Dissipation Constant
The amount of power needed to raise the thermistor’s body temperature by 1°C. At the heart of all BAPI thermistor products is a sensor with a 3 mW/°C dissipation constant to ensure that self-heating stays at an absolute minimum.

Stability (drift)
The amount that the resistance characteristics of a thermistor will change. BAPI uses only the highest quality, “pre-aged” thermistors with very small drift values. Over a ten year span, BAPI thermistor products will not change more than 0.1°C.