On Thursday, 8 December 2011, I performed a series of resistance checks to determine the health of the ring heater installed in the ITMY cartridge on H2.  The findings can be summarized as follows:

The findings can be summarized as follows:
Average ring heater resistance (in-vac wiring subtracted from measurement) = 35.6 ohms
Average resistance of a single wire leading to the heater or RTD starting at the air side pins of the vacuum feedthrough = 1.95 ohms
Upper ring heater RTD(in-vac wiring subtracted from measurement) = Not connected, damaged during installation
Lower ring heater RTD(in-vac wiring subtracted from measurement) = 108.8 ohms (this corresponds to a temperature of 22.4 C, which is reasonable)

Attached is a diagram showing the test setup and a spreadsheet used to take data.  In general, the TCS ring heater subsystem is supposed to provide two heaters (upper and lower halves of a circle), and two 100 ohm RTDs (Resistance Temperature Detectors). The RTDs give an indication of the temperature of the associated ring heater.  The resistance of the RTD varies predictably as a function of temperature.