I have a customer who has a piece of equipment that uses two decent-sized vacuum pumps. I got involved because of a motor failure on a 10 HP unit... it pulls well now, but cannot maintain. An oil mist is evident at the pump output from time-to-time.
So... does the oil mist indicate a system leak or a bad pump? What seems to happen is the thing will pull very close to the setpoint... in micron fractions... and lose it.
How do you find a vacuum leak if that is what's suspected?
Thanks,
Jake