Hi Kim,

I can't add much to the advice provided by the other posters, whether waterwill boil or not in the degassingchamber is not really a precise indication of the pressure the vacuum pumpis achieving and will having the undesirable side-effect of emulsifying the vacuumpump oil (please take a look at it, if it's appearing 'milky' now then Iwould suggest dropping the oil out and replacing it with new vacuum pump oil).

The vacuum gauge on our degassing chambers is a basic indication of thepressure in the chamber but once you're up to very high levels of vacuum thenchanges in atmospheric pressure (from day to day with changes in the weather)will affect the reading and also so to will 'stiction' of the needle itself(tap the gauge and it will sometimes move a little). If you've bought ourvacuum pump from new then it's highly likely that it will be pulling thestated 99.995%.

It's well worth checking that there are no leeks on the chamber's fittingsthough by doing a simple (and reliable) test: Once the chamber has pulled downfully (wait 2-3 minutes), leave the pump running and try opening and closingthe 1/4 turn valve on the VP4300Vacuum Pump itself. If the sound the pump makes whilst running does notchange at all as you open and close the 1/4 turn valve then the chamber and allits fittings are perfectly sealed. If there is even a minute leak anywhere inthe system then opening and closing the 1/4 valve on the pump will cause thesound that the pump makes to change slightly and you know you have a leak(maybe very small) and so should check the fittings by tightening them orreplacing the PTFE tape.

I hope this helps.

Matt