Fusor Forums

I agree with Rich - something is wrong; either the operation, the set up or the pump. To start isolating the problem, first off, do the test I suggested and determine if the roughing pump is even operating properly - certainly you should get below 70 microns. Getting just 70 microns with no load is not acceptable for a system meant to run a DP. That is very poor. If the test again gives just 70 microns pumping only on the gauge either - 1) the roughing pump oil is no good and/or contaminated or 2) The roughing pump isn't meant to achieve a lower vacuum or 3) leaks somewhere that is causing this high reading, or 4) your gauge is off (is oil in the detector head, maybe?)