Cryo-con Model 24C
Specifications, Features and Functions
PTC Resistor Sensors (RTDs)
The formulas for PTC resistor sensor in the PTC100 range are:
Where:
MAR is the electronic Measurement Accuracy in Ohms
MAT is the Measurement Accuracy in Kelvin
SenVal is the sensor reading in Ohms at the desired temperature.
SenSen is the sensor sensitivity in Ohms / Kelvin at the desired temperature.
To calculate the measurement accuracy of the Model 24C using a 100
W
Platinum
RTD in the PTC100 range with the sensor at 77.35K, look up the sensor reading and
sensitivity in
Appendix G
. The appendix shows that SenRdg is 20.38
W
and SenSen is
0.423
W
/Kelvin. Therefore, the computed values show that MAR = 0.004038
W
and
MAT = 9.5mK.
For ranges other than PTC100, please refer to the
PTC Specifications
table.
NTC Resistor Sensors
The formulas for NTC resistor sensors are:
Where:
MAR is the electronic Measurement Accuracy in Ohms
Range is the resistance range in Ohms (100, 1K or 10K)
MAT is the Measurement Accuracy in Kelvin
SenVal is the sensor reading in Ohms at the desired temperature.
SenSen is the sensor sensitivity in Ohms / Kelvin at the desired temperature.
To calculate the measurement accuracy of the Model 24C using a Cryo-con R500
Ruthenium-Oxide sensor in the 1K
W
range with the sensor at 1.0K, look up the
sensor reading and sensitivity in
Appendix G
. SenVal is 2327
W
and SenSen is
-1203
W
/Kelvin. Therefore the computed values equal MAR = 0.17
W
and MAT =
100
K.
28
MAT
MAR
SenSen
MAT
MAR
SenSen
MAR
5.0 10
5
SenVal
5.0 10
5
Range
MAR
0.002
1.0 10
4
SenVal
