T, M, C

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Vishay Dale

Revision: 24-Sep-15

4

Document Number: 33003

THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT

POINT MATCH TOLERANCE

The standard leaded thermistors are calibrated and tested at 25 °C to a tolerance of ± 5 % or ± 10 %; however, tighter tolerance,

point matched thermistors are readily available as are special point match temperatures to fit your application.

Since these thermistors have only one controlled point of reference (the point match temperature), the resistance at other

temperatures is given by the specific curve resistance vs. temperature ratio.

POINT MATCH TOLERANCES VS. TEMPERATURE

Fig. 1

Point match resistance tolerances at temperatures other

than 25 ºC are not the same as at the calibration

temperature. This difference is presented in figure 2.

The tolerance at any given temperature is the point match

tolerance plus a manufacturing tolerance depending on the

specific curve.

DESIGN-IN SUPPORT

A spreadsheet is available for the Vishay thermistor part numbers that gives you the resistance vs temperature data, the

temperature coefficients and accuracy levels at any given temperature range and step. The Steinhart & Hart formula and

coefficients A, B, and C are shown as well. This data can be obtained by visiting the Vishay NTC curve computation page at:

25 °C

NOMINAL R vs. T

MAX. R vs. T

MIN. R vs. T

PIVOT POINT

(CALIBRATION TEMPERATURE)

TEMPERATURE