Inlet wont return to test temperature

[vehans]

Im running High temperature simulated distillation and for the past couple of days I have been experiencing a problem with my inlet port, where it will stay at (or even go higher than) the final test temperature and wont return to its initial test temperature for the next sample to be analyzed (the GC gives an error that the inlet temp isn't reaching the test temp). The initial temp is 50C and ramps up to 440 at 15C/min; final oven temp is 445C. I would like to know how the inlet cools itself down (does it cool down with the oven?) and any other useful information of course would be greatly appreciated.


The GC is an Agilent 7890A with a COC Inlet

Thank you in advance!

[Consumer Products Guy]

My Agilent GCs are older, so disclaimer.

Mine cool the inlet just from the oven fan, so when running at high temperatures would take a while for the inlet to cool this way. It appears from your post (a little confusing, at least to me) that your initial oven temperature is 50 °C. What is your inlet temperature set at?

An inlet set at low temperature will take longer to cool than will the column oven.

[Himar]

There is also a small fan on top of the GC behind the inlets, it is called the inlet fan. This helps to cool the inlets as well.

[vehans]

Figured out the issue...the heating sensor on the COC inlet was failing, changed it and everything is back to normal.

Thank you for your support!