Chromatography Forum

There is an adapter that goes into the FID output and then connects to the tube of the flow meter. Is it possible to DIY an adapter or just not use one and make a proper measurement?

Are those adapters readily available?

You need a tight seal so that all the gas flow goes through the flow meter. The adapters are available - check with the vendor of your instrument or your favorite suppiler of GC consumables.

just pay the $60 bucks and get the adapter. Both Restek and Agilent sell it.

ok, I will.

There is a P/N 19301-60660 for this if i am not mistaken. But i can not see a reason not to connect the silicon tube of the flowmeter directly on your FID jet. There is no need to have the temperature on to measure the gases.

There is a P/N 19301-60660 for this if i am not mistaken. But i can not see a reason not to connect the silicon tube of the flowmeter directly on your FID jet. There is no need to have the temperature on to measure the gases.

The temperature of the detector you mean? The detector though gets hot from the oven.

To get a good seal,you would have to pull the tubing past the conical tip and onto the flats for the wrench. This does not work well. (Won't tell you how I know. But I did obtain an adapter so I could make the measurement...)

You didn't mention what GC you have. The adapters are usually different for various vendors. P/N 19301-60660 is for Agilent/HP FID's. The reason I wouldn't lower the FID temp to check flows is you can create leaks. The ferrules contract when cooled and expand when heated. I've done it in a pinch, but wouldn't make a habit of it. Restek has most of the adaptors. You can also run a free wanted ad on LabX. If I had a spare one, I'd send it to you, but I don't. Good luck.

As I am thinking - sealing to the jet would get only the carrier, makeup and hydrogen. Sealing to the inside of the chimney is tricky also... (It has been a long time since I tried measuring the flow from the FID without the adapter. And, the memories of that day come back slowly.)

There is a P/N 19301-60660 for this if i am not mistaken. But i can not see a reason not to connect the silicon tube of the flowmeter directly on your FID jet. There is no need to have the temperature on to measure the gases.

The temperature of the detector you mean? The detector though gets hot from the oven.

Yeah, and why do you need oven temp. to measure the gas flow? Since you do not have the adapter and you do not want to buy it, try to connect your flowmeter directly to the cold tip of the jet, it will take 5 minutes if you have a digital gas flowmeter. Of course i agree that the graphite ferrules expand with temp. but if you run the oven program a couple of times and screw the nut half a turn it will seal for good. Just make sure that you do not have any other leaks from the gas cylinders to the GC (check the filter connections specially the triple one (for He) on the base is tricky).

There is a P/N 19301-60660 for this if i am not mistaken. But i can not see a reason not to connect the silicon tube of the flowmeter directly on your FID jet. There is no need to have the temperature on to measure the gases.

The temperature of the detector you mean? The detector though gets hot from the oven.

Yeah, and why do you need oven temp. to measure the gas flow? Since you do not have the adapter and you do not want to buy it, try to connect your flowmeter directly to the cold tip of the jet, it will take 5 minutes if you have a digital gas flowmeter. Of course i agree that the graphite ferrules expand with temp. but if you run the oven program a couple of times and screw the nut half a turn it will seal for good. Just make sure that you do not have any other leaks from the gas cylinders to the GC (check the filter connections specially the triple one (for He) on the base is tricky).

With constant pressure wouldn't flow change with higher temperatures?