Hi Everyone,
Thank you for all the responses and suggestions. The meter that measures
the gas flow rate is called a rotameter. When combined with a flow valve
and suitable pressure gauge, it is a regulator. Below is a summary of the
different options available.
Thanks again,
Mark
MR resources sells a complete helium fill kit to pressurize the liquid
helium dewar. I’ve asked for a price/quote but have not received it yet:
http://mrr.com/nmr-helium-fill-kits.htm
I received several responses from people who use their own set up with
parts from various vendors: We use a home-built pressurization device
consisting of a 0-25 liter per minute rotameter flow gauge, a Norgren model
11-018-146 precision pressure regulator (inlet: max. 10 bar, range 0.07-0.7
bar or 1-10 psig) and an Ashcroft pressure gauge (0-5 psig / 0-35 kPa).
None of these components has ever failed during over 10 years of use. The
pressure gauge and flow meter are both available from Cole-Parmer. The flow
meter is useful for detecting if the liquid helium is exhausted before the
magnet is full; the helium gas flow rate will increase dramatically once
there is no liquid helium separating the pressurizing gas and the inlet of
the transfer line. Be sure to use a flow meter with a needle valve since
this valve may need to be adjusted to prevent oscillations in the flow rate
during filling.
Additional links:
1)
http://www.dwyer-inst.com/Product/Valves/AirFilters-Regulators/SeriesMPR/Ordering?gclid=CO2Iw5bKhcMCFchffgod8TQArg
2)
http://www.mcmaster.com/#digital-pressure-gauges/=vds6bm
3) Vernier pressure sensor (
http://www.vernier.com/products/sensors/gps-bta/)
and LabQuest interface.
4)
http://www.mathesongas.com/catalog/category.aspx?category_id=20&mode=home
Received on Fri Jan 09 2015 - 08:51:26 MST