I apologize for asking about the same topic again, but we are really at a loss now.
After a long time we put an older MAT 253 back into operation and do not get any linearity and actually I do not like
the stability either.
Source is clean (cleaned by Thermo), the filament is quite new, vacuum is good, background values are ok, water is
around 1000 mV.
At the moment it’s connected only to a ConFlow III and we measure CO2. We have disconnected the EA and TC / EA in
order to rule out a faulty influence.
At the beginning we had a lot of water in the system, especially in the needle valve. If we turned on the needle valve
heater, we had 50V.
The stability is ok after about 30 to 60 minutes (Stdev 10 pulses around 0.05), but in the first std_on_off runs of
each day there is an enormous drift (min value to max value up to 4 permille over 10 minutes). I've never seen anything
like that before.
If we felt that the MAT was now quite stable and we wanted to focus on linearity, we found that it does not matter
which extraction is set. We do not get any linearity.
If anyone still has any idea, please let me know!
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