aidan.brooks@LIGO.ORG - posted 13:41, Tuesday 26 September 2017 - last comment - 08:09, Wednesday 27 September 2017(38785)
Ring heater RTD status - resistance check
I went and checked the cables from the ring heaters where they are attached to the RH drivers in the CER. I wanted to confirm what pins are connected correctly to the RH RTDs (out of the 4 wires that go to the RTD) - see D1200505. The following tables summarize the measurements.
Conclusions: ITMX & ETMY RH RTDs are not salvageable.
ITMX
| PINS | 7 | 8 | 20 | 21 |
| 7 | x | 9.4 Ω | OL | OL |
| 8 | x | x | OL | OL |
| 20 | x | x | x | 9.5 Ω |
| 21 | x | x | x | x |
ITMY
| PINS | 7 | 8 | 20 | 21 |
| 7 | x | 9.3 Ω | 117.4 Ω | 117.3 Ω |
| 8 | x | x | 117.3 Ω | 117.3 Ω |
| 20 | x | x | x | 9.7 Ω |
| 21 | x | x | x | x |
ETMY
| PINS | 7 | 8 | 20 | 21 |
| 7 | x | 7.8 Ω | OL | OL |
| 8 | x | x | OL | OL |
| 20 | x | x | x | 7.9 Ω |
| 21 | x | x | x | x |
Do you have any information about when these broke? Have these been connected to readout channels continuously?
As far as we know these were broken during clean and bake (or during assembly). Given that we didn't have multiple spare cables, we couldn't replace them.
Yes - these have been connected to readout channels continuously (see D1003254).