Indirect estimation of helium pressure at cryogenic temperatures

To enhance robustness of automated Temperature vs parametertype of measurements in a cold exchange gas based sampletemperature control system, a second control loop is being addedto compensate for pressure variations. For this purpose, a methodfor indirect estimation of He gas pressure has been devised andtested. The method depends upon the property that in the closedloop sample temperature control system, the heater power at thesteady state changes with the partial pressure of the cold Heliumgas