Chromatography Forum

Dear All,

I have a Perkin Elmer Clarus 500 GC in my lab. We have a capillary column connected to it. During the experiment, we got an error message saying CAR1 PPC shut down and the gas flow rate went down. We then replaced the carrier gas cylinder with a new one. Removed all the inlet connection lines and checked for leaks and reconnected it. Again after restarting the instrument, the pressure builds up and then slowly drops down and again PPC shut down occurs.

We tried to figure out if there are leaks at the column inlet and outlet as well and found no leaks.

We suspect whether the pressure sensor is having the fault.

Can anyone suggest any method to find out where is the exact problem and help in troubleshooting the issue.

Thanks,
Selva

Get an old-fashioned dial pressure gauge (the kind that cylinder regulators have on them) and connect it to a hollow needle. Push the needle through the inlet septum and you have an independent measure of inlet pressure (I presume that this is what the sensor is supposed to measure).

Also look at gas flows - if the gas flows stay the same while the sensor says that the pressure is dropping it is likely that the sensor is faulty. Needless to say you should measure the flows independently of the onboard pneumatics - using a bubble flow meter for example.

Peter

If you are certain that you do not have leaks at bulkhead fitting, union fitting between the PPC module and the inlet, or inside the oven at column fitting - then you likely have a bad PPC module (either the flow module or the head pressure module or both).
Try rebooting the GC. Do you get a message stating: Warning CAR 1 pressure less than 50 psi?
Is this a CAP inlet? What is your column flow set point? Do you have the split ratio turned on? Make sure you have some split flow on .... maybe 40:1.

Hi

I have the same issue on my Perkin elmer GC 'Warning CAR 1 pressure less than 50 psi'

Please advice.

Thank

If you are certain that you do not have leaks at bulkhead fitting, union fitting between the PPC module and the inlet, or inside the oven at column fitting - then you likely have a bad PPC module (either the flow module or the head pressure module or both).
Try rebooting the GC. Do you get a message stating: Warning CAR 1 pressure less than 50 psi?
Is this a CAP inlet? What is your column flow set point? Do you have the split ratio turned on? Make sure you have some split flow on .... maybe 40:1.

Hi

Mine dont have a CAP inlet. Column flow rate is 10psi, 24cm/sec. Split ratio of 90:1