Keithley DMM7510 Calibration Manual page 44

Model DMM7510 7½ Digit Graphical Sampling Multimeter Calibration Manual
RTD equations
The temperature vs. resistance readings listed in the RTD reference tables are calculated using the
Callendar-Van Dusen equation. There are two equations, which are based on different temperature
ranges. There is an equation for the -200 °C to 0 °C range and one for the 0 °C to 850 °C range.
Equation for -200° to 0°C temperature range
R = R
RTD
where:
•
R
RTD
•
R is the known RTD resistance at 0 °C
0
•
T is the temperature in °C
•
A = alpha [1 + (delta/100)]
•
B = -1 (alpha)(delta)(1e-4)
•
C = -1 (alpha)(beta)(1e-8)
The alpha, beta, and delta values are listed in the following table.
Equation for 0 °C to 850 °C temperature range
R = R
RTD
where:
•
R
RTD
•
R is the known RTD resistance at 0 °C
0
•
T is the temperature in °C
•
A = alpha [1 + (delta/100)]
•
B = -1 (alpha)(delta)(1e-4)
The alpha and delta values are listed in the following table.
RTD parameters for equations
The RTD parameters for the Callendar-Van Dusen equations are listed in the following table.
Model DMM7510 resistance to temperature device (RTD)
Type
PT100
D100
F100
PT385
PT3916
DMM7510-905-01 Rev. A / April 2015
2 3
[1 + AT + BT + CT (T-100)]
0
is the calculated resistance of the RTD
2
(1 + AT + BT )
0
is the calculated resistance of the RTD
Standard Alpha
ITS-90 0.00385055
0.003920
0.003900
IPTS-68 0.003850
0.003916
Beta Delta
0.10863 1.49990
0.10630 1.49710
0.11000 1.49589
0.11100 1.50700
0.11600 1.50594
Section 2: Performance verification
R at 0 °C (Ω)
0
100.0000
2-35