Gas flow issue
Posted: Fri Jan 30, 2015 12:06 am
by FBProc
Having issues with a 6850 GC. It can't maintain gas flow setpoints for more than about 2 seconds. The gas flows fall to about half their setpoint values after a couple seconds then fall even further. After maybe 20 seconds the machine tries again and the same thing happens. Any ideas as to what I can try to troubleshoot the problem? I had contacted Agilent about this problem last year and they said the EPC valves are faulty but would like some more opinions.
Re: Gas flow issue
Posted: Fri Jan 30, 2015 3:19 am
by Warack
When I came back from working over a weekend, and somebody had tried to run a bakeout with very little hydrogen left causing an influx of oxygen before everything cut off. The oxygen(in a hot oven) caused a fracture in my silica capillary column(pretty old column) that was not visible until I tried to move it to check and a piece fell off in my hands. I would try moving the column some before getting into anything too extensive , and see if there is any damage. I ended up using a ceramic wafer to cut the fractured piece to a flat edge, and put it back. Ran solvent through to clean it up and adjusted the retention time, and it was as good as new.