I have a problem with the high vacuum value reported by my Agilent QQQ 6430: its value is about 10-9 but it should be max 10-7 torr. Considering that the high vacuum gauge works well, anyone can help me to discover the cause?
Units of gauge?
I have never worked with said device, but standard thinking would be to swap gauge with similar and retest and test both gauges simultaneously. Possibly a recalibration is needed(?).
If it is an ionization gauge, check for oxidation/corrosion on the anode connector causing a high resistance.
Steve can be right. We face sometimes a weird behaviour of oxidised Penning gauges. I clean old ones with fine sandpaper and solvent (acetone/IPA). However, it isn't a good idea to clean ones under warranty.
What type of gauge is there?