Just wondering if anyone has had the fan inside a Delta V (top of the chimney, beside the turbo) fail.  I cant make up my mind if its the fan or turbo beginning to make periodic rattling noises.  If you've worked in a lab as long as I have you become attuned to background noise and are susceptible to these types of little changes!  As the machine was in hiatus over Christmas with needle valve closed, thought I'd take the opportunity to change the oil in the backing pump and run a hoover over the area.  Im leaning towards the fan as pre-shutdown vacuum was in the mid -8s  and as I've turned everything back on again, the vacuum is coming down as expected.  Ive also done the screwdriver to the ear trick and the pump noise is constant while the chimney seems to confirm my suspicions.  Anyway just seeking any other observations and if it was to fail, say over the weekend, how damaging could this be


Stable Isotope Facility
School of Natural and Built Enviornment
Queen's University Belfast
Northern Ireland