58 Chapter 4 Temperature Controller Module Operation
C2 = B * 10
+4
C3 = C * 10
+7
The constants C1, C2, and C3 may all be expressed in the form n.nnn simplifying
entry into the 8000.
If high accuracy is not required, the Steinhart-Hart equation may be simplified to a
first order polynomial:
1/T = A' + B' * Ln R
This equation is easier to solve and often provides adequate results. The table also
shows that the use of the simplified equation introduces temperature errors of less
than 0.5°C over the range -20°C to 50°C. Once the constants A' and B' are
determined, the 8000 is programmed with the following values of C1, C2 and C3:
C1 = A' * 10
+3
C2 = B' * 10
+4
C3 = 0.000
4.5.1.7 Table of Constants
We have listed some common thermistors and included the appropriate calibration
constants for the temperature range -20°C to 50°C in Table 7. The Model 8000, by
default, uses the BetaTHERM 10K3A2 thermistor values.
Manufacturer C1 C2 C3
BetaTHERM 10K3 1.129241 2.341077 0.877547
BetaTHERM 0.1K1 1.942952 2.989769 3.504383
BetaTHERM 0.3K1 1.627660 2.933316 2.870016
BetaTHERM 1K2 1.373419 2.771785 1.999768
BetaTHERM 1K7 1.446659 2.682454 1.649916
BetaTHERM 2K3 1.498872 2.379047 1.066953
BetaTHERM 2.2K3 1.471388 2.376138 1.051058
BetaTHERM 3K3 1.405027 2.369386 1.012660
BetaTHERM 5K3 1.287450 2.357394 0.950520
BetaTHERM 10K3 1.129241 2.341077 0.877547
BetaTHERM 10K4 1.028444 2.392435 1.562216
BetaTHERM 30K5 0.933175 2.213978 1.263817
BetaTHERM 30K6 1.068981 2.120700 0.901954
BetaTHERM 50K6 0.965715 2.106840 0.858548
BetaTHERM 100K6 0.827111 2.088020 0.805620
BetaTHERM 1M9 0.740239 1.760865 0.686600
Table 7 - Thermistor Constants
4.5.2 AD590 and LM335
AD590 and LM335 sensors are not supported on dual or combination TECs.
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