[Dsg-mvt] Status about MFC for isobutane

[SABATIE Franck]

Dear Marc,

Thanks for the update. Concerning heating up the enclosure: we are slightly worried about the aluminum plate which both acts as a support plate on which the MFCs are bolted on and as a « radiator » (the heat tapes are round around it): indeed, to keep the enclosure to at least 60F means heating up that plate a lot and the MFCs are on it: large temperature gradients are probably not great for those MFCs. It might be safer to use two plates: one for MFC support, one as the radiator for the enclosure.

Cheers,
Franck

Le 12 déc. 2017 à 12:43, Marc McMullen <mcmullen at jlab.org<mailto:mcmullen at jlab.org>> a écrit :

Hi Maxime,

I should have the spare tested with N2 (room temperature) by some time tomorrow. I will ask Todd to install it at the valve panel at that point. I will ask the system owner if there is a possibility to make some changes to the valve panel to make testing and future maintenance of the mfcs much easier. But not sure when that would happen. After we swap out the mfc, I'll try the same tests with Argon and lastly C4H10.

One thing I thought may be a possible issue was the temperature. The low range operating range of the MFC is 50 deg. F. I'm not sure where it was being measured from previously, but I moved the RTD sensor for the gas pad (B_SYS_WEATHER_GP_Temp) inside the enclosure yesterday around 9:30am. I think we may want to bump that heating coil for the MFCs a little bit. I have attached a screen shot of the temperature since 12/6, I believe the plan was to keep the temperature above 60 degrees.

I'll keep everyone informed on the progress.

-Marc
On 12/12/2017 10:58 AM, mdefurne wrote:
Hi Marc,

What are the news concerning the tests you wanted to run with the spare Isobutane MFC?

Kind regards,

Maxime


--
Marc McMullen
Detector Support Group
757-269-7738

<MVT_gaspad temp.JPG>
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