Keithley 2510 - Sensor Coefficients; Thermistor Coefficients; RTD Coefficients

4-14 PID Control Concepts Models 2510 and 2510-AT User’s Manual
Sensor coefficients
Thermistor coefficients
The thermistor sensor coefficients A, B, and C linearize the thermistor temperature-
resistance curve and are related using the Steinhart and Hart equation as follows:
Where:
T = Temperature (K)
R = Thermistor resistance (ohms)
A, B, C = Thermistor sensor coefficients
These coefficients should be set to values specified by the thermistor manufacturer. See
“Configuring temperature,” page 3-3, for programming details.
RTD coefficients
In a similar manner, RTD sensor coefficients α, β, and δ linearize the RTD temperature-
resistance curve using the Callendar-Van Dusen equation in the following manner:
Where:
R
T
= Resistance at temperature T (°C).
R
0
= Resistance at temperature 0°C.
α = Temperature coefficient at 0°C (typically 0.00392Ω/°C).
δ = 1.49 (typical for 0.00392 platinum RTD).
β = 0 for T >0°; 0.11 (typical) for T<0°.
These coefficients should be set to values specified by the RTD manufacturer. See
“Configuring temperature,” page 3-3, for programming details.
1
T
--- AB1nR[]C 1nR[]
3
++=
R
T
R
0
R
0
α T δ –
T
100
---------1–


T
100
---------


β
T
100
---------1–


T
100
---------


3
–+=