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Recommendations for GC leak detector and flow meter

Posted: Fri Feb 14, 2020 11:37 am
by MJJohnson
I am fairly new to using GC's and trying to fix a problem with the Shimadzu GC2010plus in our lab. We currently don't have either a leak detector or flow meter for GC's so I can't check for leaks or check the flow through the column. Could someone please recommend which ones to purchase.

Many Thanks

Re: Recommendations for GC leak detector and flow meter

Posted: Fri Feb 14, 2020 1:15 pm
by Consumer Products Guy
Retired now; but we purchased these from Restek.

Re: Recommendations for GC leak detector and flow meter

Posted: Fri Feb 14, 2020 8:44 pm
by James_Ball
Yup, Restek sells them as a pair for a little discount if I remember. We use both of them.

https://www.restek.com/catalog/view/39910

Re: Recommendations for GC leak detector and flow meter

Posted: Sat Feb 15, 2020 7:14 am
by nipe
Agilent ADM-1000 flow meter and snoop bubble leak tester

Re: Recommendations for GC leak detector and flow meter

Posted: Tue Feb 18, 2020 2:15 pm
by antonk
* Restek leak detector is a must.
* Restek flow meter was developed by audiophile:
600 Ohm (not 8, not 16, not 32, 600 Ohm) Sennheiser headphone (as rare as Mozart handwritten notes) used as volume sensor in chamber filled with gas being measured.
Once the "sensor" was broken (fall from the table) Nikon microscope with x20 objective used for searching wire break (wire is thinner than human hair).
We gave up.

Re: Recommendations for GC leak detector and flow meter

Posted: Tue Feb 18, 2020 5:00 pm
by James_Ball
nipe wrote:
Agilent ADM-1000 flow meter and snoop bubble leak tester


Snoop not a great idea for checking for leaks at the bottom of the inlet or at the septa, it can be sucked into the inlet by the Venturi effect and contaminate they system. The same way oxygen appears even when helium is leaking out of the inlet. Also it is not good near the EPC, as water and electronics are not a good combination. I know that one from experience :(

Re: Recommendations for GC leak detector and flow meter

Posted: Tue Feb 18, 2020 11:52 pm
by LALman
RESTEK leak detector here. Well worth the money. Being able to find even tiny leaks has really reduced my helium usage. On the other hand it stopped charging after a year. They said you need to charge it after every use. Plus its really easy to mess up the sensor with micro fibers from insulation. So, be very careful about checking valves and fittings that have had contact with insulation.

Re: Recommendations for GC leak detector and flow meter

Posted: Wed Feb 19, 2020 4:10 am
by benhutcherson
Restek leak detector for me here also, and an ancient J&W Scientific electronic flow meter.

I do keep a couple of soap bubble meters around, but I use them more for verifying flow than I do measuring. Truth be told, I've mostly phased that use out, as a beaker of methanol is just as informative and a lot less temperamental.

On Snoop-Agilent in particular is very adamant about not using it. Among other reasons, I've seen it stated that even a fitting under pressure with a leak can still draw Snoop into it by the Venturi effect. I've seen documentation stating that if you must use a liquid leak tester, to use isopropanol instead.

Re: Recommendations for GC leak detector and flow meter

Posted: Thu Feb 20, 2020 10:28 pm
by James_Ball
LALman wrote:
RESTEK leak detector here. Well worth the money. Being able to find even tiny leaks has really reduced my helium usage. On the other hand it stopped charging after a year. They said you need to charge it after every use. Plus its really easy to mess up the sensor with micro fibers from insulation. So, be very careful about checking valves and fittings that have had contact with insulation.


Strange, we have been using ours for about four years now and I have only charged it twice. Once when we received it and again about a year and a half ago.

The flow meter though, will eat through cheap batteries pretty quickly.

Re: Recommendations for GC leak detector and flow meter

Posted: Fri Feb 21, 2020 4:09 pm
by LALman
RESTEK told me I should always charge after use rather than wait till the charge light flashes. Their tech said there were fibers blocking the detector and wanted to charge for a cleaning. I explained that seemed impossible since I only checking free standing valves and fittings. Because it was nearly new, they refurbished it without charge.

Re: Recommendations for GC leak detector and flow meter

Posted: Sat Feb 22, 2020 9:50 am
by dblux_
LALman wrote:
RESTEK told me I should always charge after use rather than wait till the charge light flashes...

Restek exagerates the problem. You don't need to charge that leak detector after each use. However as it has lithium battery you should not let the voltage drop below certain level. If it happens the security circuit prevents battery from charging forever. It is clearly stated in the instructions manual.
If it happens you may remove the battery from the meter and charge it with Li battery charger or laboratory power supply according to battery datasheet.
If the battery lost it's capacity you may buy such battery from the market and it will be much cheaper than Restek service.

Re: Recommendations for GC leak detector and flow meter

Posted: Tue Feb 25, 2020 12:14 am
by Jake
We have Restek and Agilent leak detectors. The Agilent hardly gets used. Not sure why, but no one seems to like it. We've had the Restek one 10+ years. Works reasonably well. We do charge after each use, primarily because ours cannot be used while it's charging.

We have the Restek flow meter too. Not sure how valuable this really is. It is nice for troubleshooting system flow drops since you can log with software over many hours/days. But it's not very accurate and we've never solved a problem by using it.

No snoop in our lab, for the good reasons mentioned.