What could be the problem? I have tried changing the septum, liner and o-ring. I could still start sample run though.
I have updated the tags on your post for better visibility . Please let us know what type of inlet, and the flow paramters such as pressure , total flow, column , oven starting temp etc.
Thank you for the updated tags. The parameters are as follows:
*None of parameters have been changed. The issue of the inlet pressure fluctuating suddenly happened. Tried to off and on the inlet temperature and pressure and noticed that at some point when the temperature was still increasing to its set point (250 'C), the inlet pressure which had reached set point (246 psi) first had stop fluctuating. However, once the temperature reached 250 'C, the fluctuation happened.
OVEN Temp: 70 'C (On)
Final Temp: 220 'C
Final Time 1: 32 min
FRONT INLET (SPLITLESS/SPLIT) Mode: Split Initial temp: 250 'C (On) Pressure: 246.00 psi (On) (fluctuating between the range of 245.80 to 246.02) Split ratio: 20:1 Split flow: 20.0 mL/min Total flow: 25.09 mL/min (realise that this has been fluctuating as well; could be due to the fluctuating inlet pressure) Gas saver: On Start flow: 20
Start time: 2
BC-WAX, 0.25 mm x 50 m, df 0.15 um
Is the pressure setting a typo? The split/splitless high pressure inlet is only rated to 150psi, regular inlet to 100 psi.
Oh yes. It should be 246 kpa.
As a follow-up to James' question and observation, can you post the details of your system? What model GC and MSD are you using, and what software are they controlled by?
GC model: Agilent 7890A
MS model: Agilent 5975 series
Chemstation is used.
Do you still see a pressure fluctuation with gas saver off?
If these pressures are in kPa, then the fluctuation in pressure is acceptable . The conversion to PSI would be 35.67 with a pressure fluctuation of 0.22 psi.
Thanks for the information. However, these setting has not been change for quite a period of time. It was the first time encountering this as well. Hence, was thinking that there is some problem going on.
While the pressure fluctuation is within spec, it maybe time to change the split vent cartridge if this hasnt been changed in awhile.
Here is a link to a video that will aid in this if you have never done this before.
Change the Split Vent Trap - GC Troubleshooting Series | Agilent
Thank you. Will try to change it.
I will mark this post as assumed answered due to age. If this isn't the case, feel free to post again. If any response was particularly helpful, feel free to mark as correct answer .
Retrieving data ...