Cryo-con Model 24C Specifications, Features and Functions
Cryogenic Linear Temperature Sensor (CLTS)
Supported by use of a 100uA constant-current AC resistance bridge. A standard
calibration curve for the Vishay CLTS-2B sensor is available on the utility CD.
Maximum resistance is 1.2K and minimum is 10. Sensor type is PTC1K.
PTC Resistor Sensor (RTDs)
The Model 24C supports all types of Positive-Temperature-Coefficient (PTC) resistive
sensors using a constant-current AC or DC resistance bridge technique.
Standard calibration curves are provided for DIN43760 and IEC751 Platinum sensors.
These curves have been extended down to 14K. Below that, the sensors can be used
with user supplied calibration curves.
A table of recommended setups for various types of PTC resistor sensors is shown
here:
Type Measurement Range Sensor Excitation
Platinum, 100 1.0K - 0.01
1.0mA, AC
Platinum, 1000 10K - 0.1 100mA, AC
Rhodium-Iron
1.0K - 0.01
1.0mA, AC
Table 11: PTC Resistor Sensor Configuration
When AC excitation is On, the sensor excitation current is a 10 Hz square wave. This
square wave excitation generates a small noise signal in the sensor cable, which can
be picked up by sensitive measurement equipment in the system. Turning AC
excitation Off will eliminate this noise at the cost of introducing a thermal EMF DC
offset voltage into the sensor measurement.
31
To Next Page
Loading...