| Greetings ISOGEOCHEMers, I noticed that several months ago there was a discussion regarding spontaneous emission outages in people's Delta+XP. I am now experiencing all of the same symptoms mentioned in that discussion. Namely: Box and Trap currents drop to zero Emission LED turns off HV stays at 3.04kV Filament has low resistance and is continuous as measured across pins 1 & 10 1.4 x10-6 vacuum reading on ISODAT 2.0 Measured 6.8V across MP11 and MP13 on the Power Distro board (Penning Guage Safety Trip) Power cycling the computer did not resolve problem Cutting power at the mains on the mass spec did not resolve the problem This is the second time this has occured on this instrument in as many months. Last time that it happened I suspected the filament was blown so I replaced it. That did not resolve the problem then and from my observations I doubt that this is the problem this time. The filament that I removed last time did not seem damaged and was fairly new. Several days later the emission just turned on overnight last time and I began measuring with it again and all seemed well with the data. Having read several posts to the listserver where similar problems were reported, I know that others are experiencing this as well. I was wondering if anybody has determined what causes this to occur (and of course how to fix it). Thanks for your time and have a nice weekend, Benjamin Miller Manger, Idaho Stable Isotopes Laboratory University of Idaho College of Natural Resources Dept. Forest Resources [log in to unmask] |