chandra.romel@LIGO.ORG - posted 11:55, Tuesday 05 November 2019 - last comment - 07:51, Wednesday 06 November 2019(53015)
PT-110 pressure gauge swap on HAM6
{Gerardo, Chandra}
Replaced faulty PT-110 pressure gauge (SN 217) on HAM6 today with SN 214; however, the hot filament will not come on after some pressure transitions. I've asked Patrick to try to force it on through software when he is on shift tonight. Here is what we did:
- isolated gauge from HAM6
- connected aux cart and hung turbo
- vented gauge tee with room air
- replaced gauge
- pumped back down
- pressure fell as expected into low e-5 Torr range
- helium leak checked 2-3/4" CF (no leaks beyond 6e-10 Torr-L/s background)
- valved out turbo and then valved in gauge to main volume
- pressure is flat lined at 8e-5 Torr, suggesting the filament is not turning on after a pressure spike from isolating "wet" gauge/tee
- reset gauge, rebooted power, increased gauge pressure --> none triggered the filament
- next Patrick will run emissions command in software
- if that doesn't work we will replace with a different model gauge
Gauge is Inficon BCG450-SE and was tested on pump cart prior to installation. IP14 and small 10 l/s IP on RGA both remain stable.
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In order to connect the pump cart, I had to temporarily move the PEM Vibration Table sitting on 16.5" flange set on top of HAM6.
I set the units for the gauge to Torr. It is now reading around 6E-7.
Thank you, Patrick!!