Reports until 17:34, Friday 20 October 2017
LHO VE (CDS)
arnab.dasgupta@LIGO.ORG - posted 17:34, Friday 20 October 2017 - last comment - 17:56, Friday 20 October 2017(39115)
Work on the Pirani Gauge on BSC-2
Rakesh, Chandra and Arnab

We worked on the calibration issue we thought the pirani gauge had on BSC-2.The sensor head was tested using a 9-pin connector connected a MKS controller which showed a nearly correct value to atm adjustments. But when it was again connected with the original cable present with the 15-pin connector and it didn't go below  885 torr. Tthen we took the electronics off the sensor head put a different one, repeated the same but it didn't changed the value. The electronic unit was then taken off  as we had some doubt and wanted to check the calibration.After the testing we found that it worked fine an the voltage would changes equally on the o/p and would go below which was desired. With all this done we tried to check by changing the cable which didn't helped either. So now we doubt that there might be some offset issue on the ADC channel with the beckhoff which didn't allow us adjust the atm, to go below 5.6V(nearly corresponds to 880 torr) when adjusted and measured at atm.  
Comments related to this report
chandra.romel@LIGO.ORG - 17:45, Friday 20 October 2017 (39117)

Thanks to Marc P. for his help rigging up wiring to test the electronics on the bench.

chandra.romel@LIGO.ORG - 17:56, Friday 20 October 2017 (39118)

aLOG 38958