We have been running the dust monitor vacuum pumps with the assumption that they had to be set to 19 inHg according to T2100415, I went out to ENDY to test this out. When I first checked out the vacuum pump, it was at 20.5 inHg, the flow meter on the dust monitor was reading at 2.8 L/min which is what we want, I then lowered the pumps pressure down to 13 and rechecked the dust monitor and its flow was now at ~2.7. I then adjust the pump down to 10 which brought the dust monitors flow to 2.65. These 1/10s of a L flow are correctable by adjusting the internal flow rate on the dust monitor. Before I left I reset the pumps pressure to 19 inHg.

It seems like we do not need to have the vacuum dust monitor pumps set to 19 inHG, the dust monitors flow rate isn't as strongly dependent on it as we thought?