I'm using the Lakeshore Model 218S temperature monitor with Cernox 1050 sensors. As it is stated in the user manual, the monitor single excitation current capability (which is fixed to 10uA) may limit the sensors low temperature range (as their resistance exceeds 7.5 kOhm). In fact, this is the case for some sensors we order, while others have the acceptable resistance range (all of them are of the same model CX-1050-CU-HT-1.4L).
The question is - as we're ordering calibrated sensors, can we choose those ones, which have the low temperature resistance values below 7.5 kOhm?
Post by Lake Shore Jeff M on Apr 8, 2020 7:43:37 GMT -5
The resistance of a Cernox sensor of the same model can vary by several thousand ohms. For example a CX-1050 sensor operating at 1.4K can typically have a resistance anywhere between 3000 to 100,000 ohms. However, the resistance of a CX-1030 sensor at the same temperature has a value between a few hundred ohms to approximately 1000 ohms.
Your options would be to use the CX-1030 sensor instead of the CX-1050 or you can contact your Lake Shore Sales Representative and have a custom sensor part number set up that would then hand pick CX-1050 sensors with a resistance below 7500 ohms. Due to the special handling required a custom sensor will have a higher price than the standard sensor does.