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Agilent GC/MS inlet pressure shutdown and GC offline issue
Posted: Wed Jan 07, 2015 5:04 pm
by chemist_girl
First, I started a run on a Friday and forgot about the sample. When I came back a week later to retrieve the data, only the first two injections results were there. There was a message on the GC panel that stated, "inlet pressure shutdown". So, I check the gas cylinder and the helium was empty. I changed the cylinder and adjusted the regulator. I restarted my run and again came back the next day to find the same message. I changed the septum and still same problem. I have restarted the run 8 times and it keeps shutting down. Now it is stating the GC is offline. I tried shutting the GC/MS down and re-powering and I also shut down the computer and rebooted it. Heeellllpppp!!!
Re: Agilent GC/MS inlet pressure shutdown and GC offline iss
Posted: Wed Jan 07, 2015 7:28 pm
by dblux_
First, I started a run on a Friday and forgot about the sample. When I came back a week later to retrieve the data, only the first two injections results were there. There was a message on the GC panel that stated, "inlet pressure shutdown". So, I check the gas cylinder and the helium was empty. I changed the cylinder and adjusted the regulator. I restarted my run and again came back the next day to find the same message. I changed the septum and still same problem. I have restarted the run 8 times and it keeps shutting down. Now it is stating the GC is offline. I tried shutting the GC/MS down and re-powering and I also shut down the computer and rebooted it. Heeellllpppp!!!
Start with finding a leak in helium line. (I assume this was a GC method you did not modify and previously functional).
Re: Agilent GC/MS inlet pressure shutdown and GC offline iss
Posted: Wed Jan 07, 2015 7:49 pm
by Peter Apps
I am sorry to say that troubleshooting by pressing start and walking away is rarely productive. As is doing the same thing over and over again expecting a different result. You need to check your system for leaks with a leakseeker, and check that the flows and pressures are really at their set values and that they stay at their set values during a run. If you are running constant flow with a temperature programme the inlet pressure increases and leaks can happen late in the programme in a system that is leak tight at the starting conditions.
Re: Agilent GC/MS inlet pressure shutdown and GC offline iss
Posted: Tue Jan 13, 2015 8:06 am
by gcguy
Is th instrument connected using LAN of GPIB? I have seen problems with network cards not clearing errors when rebooted. Believe it or not the power needs to be shut off at the outlet for a minute or so.
GCguy
Re: Agilent GC/MS inlet pressure shutdown and GC offline iss
Posted: Tue Jan 13, 2015 10:55 am
by chandresh.soni
Kindly confirm the model no. of agilent GC as this problem is related to GC only(Inlet pressure shut down). this problem came when our split valve is chowked, split line may be chowked, you may replace the split line filter. many times this problem may comes due to Valve of EPC( Pnumatic control board) this one is normal problem in the GC.
Many times if the septum purge valve is not controlling the flow at that time also this problem may occur.
try to clean the split line or filter.
Also please check your total flow(Column flow+split flow+septum purge flow) it should not exceed then your EPC capacity which I am expacting in case of helium is 1000ml maximum.
The column configuration is also an important parameter.
chandresh