Newport 350B, User Manual, Page: 52 / 66

Maintenance and Service 51
Figure 15 Thermistor Resistance versus Temperature
Error T (

C)
R
1
T Actual Third Order
Fit. Eq. 1
2
97072 -20.00 -0.32
55326 -10.00 -0.06
32650 0.00 0.09
19899 10.00 0.15
12492 20.00 0.13
10000 25.00 0.08
8057 30.00 0.01
5326 40.00 -0.20
3602 50.00 -0.50
Table 3 Steinhart-Hart Curve Fitting Accuracy
The constants C
1
, C
2
, and C
3
may all be expressed in the form n.nnn simplifying entry
into the 350B.
7.2.2 Table of Constants
Some common thermistors are listed and included the appropriate calibration constants
for the temperature range -20

C to 50

C in Table 4. Model 350B, by default, uses the
BetaTHERM 10K3A2 thermistor values.
1
Resistance of a 10K, Fenwal UUA41J1 thermistor.
2
Constants C
1
= 1.125 * 10
-3
C
2
= 2.347 * 10
-4
C
3
= 0.855 * 10
-7