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I have good connectivity to the gas flow sensor chassis in the EEL. I have submitted a request to add some PVs to the local IOC. After this is complete I should be able to start monitoring the SBS channels.</div>
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Marc<br>
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<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" style="font-size:11pt" color="#000000"><b>From:</b> jboyd@jlab.org <jboyd@jlab.org><br>
<b>Sent:</b> Tuesday, September 28, 2021 2:39 PM<br>
<b>To:</b> Marc Mcmullen <mcmullen@jlab.org>; George Jacobs <jacobsg@jlab.org>; Jack Segal <segal@jlab.org>; dsg-halla_gem@jlab.org <dsg-halla_gem@jlab.org>; adr4zs@virginia.edu <adr4zs@virginia.edu>; kagnanvo@jlab.org <kagnanvo@jlab.org>; Brad Sawatzky <brads@jlab.org><br>
<b>Subject:</b> Re: [Dsg-halla_gem] [EXTERNAL] SBS gas distribution rack moved to EEL/125; help setting up?</font>
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<div class="PlainText">Thanks everyone for the replies. I guess we are just using a lot of gas in<br>
this setup. I will wait to see what the readings are once the transducers<br>
are set up. Right now we are flowing only nitrogen however, we will<br>
eventually flow Ar/CO2.<br>
<br>
I believe Anu (and Kondo) know the appropriate flow rates that we expect.<br>
<br>
Thanks again for the help.<br>
<br>
-John<br>
<br>
> I'm working on installing the RPi in the EEL. That way we can start<br>
> reading the transducers.<br>
><br>
> Marc<br>
> ________________________________<br>
> From: Dsg-halla_gem <dsg-halla_gem-bounces@jlab.org> on behalf of George<br>
> Jacobs <jacobsg@jlab.org><br>
> Sent: Tuesday, September 28, 2021 1:59 PM<br>
> To: Jack Segal <segal@jlab.org>; jboyd@jlab.org <jboyd@jlab.org><br>
> Cc: dsg-halla_gem@jlab.org <dsg-halla_gem@jlab.org><br>
> Subject: Re: [Dsg-halla_gem] [EXTERNAL] SBS gas distribution rack moved to<br>
> EEL/125; help setting up?<br>
><br>
> Jack is correct, these flow meters have limited accuracy only within the<br>
> advertised range of the flow meter. The mass flow transducers are more<br>
> accurate and should be used to determine actual flow rates.<br>
><br>
> Dwyer RMA 12 ssv - 50sccm-500sccm<br>
> Dwyer RMA 13 ssv - 100sccm-1000sccm<br>
><br>
><br>
> --<br>
> George Jacobs<br>
> Jefferson Lab (TJNAF)<br>
> STE 12<br>
> 12000 Jefferson Ave.<br>
> Newport News, VA 23606<br>
> (office) 757-269-7021<br>
> (email) jacobsg@jlab.org<br>
> (url) <a href="https://userweb.jlab.org/~jacobsg">https://userweb.jlab.org/~jacobsg</a><br>
><br>
><br>
> ________________________________<br>
> From: Dsg-halla_gem <dsg-halla_gem-bounces@jlab.org> on behalf of Jack<br>
> Segal <segal@jlab.org><br>
> Sent: Tuesday, September 28, 2021 1:22 PM<br>
> To: jboyd@jlab.org <jboyd@jlab.org><br>
> Cc: dsg-halla_gem@jlab.org <dsg-halla_gem@jlab.org><br>
> Subject: Re: [Dsg-halla_gem] [EXTERNAL] SBS gas distribution rack moved to<br>
> EEL/125; help setting up?<br>
><br>
> I turned off all the flow meters. Turned them on a section at a time. I<br>
> think you<br>
> are just using a lot of gas. I'm not sure how accurate those visual meters<br>
> are at<br>
> low flow. Also, they are calibrated for air. You are using Ar/CO2.<br>
> What is the make and model of the visual flow meters?<br>
><br>
> On 9/28/2021 12:46 PM, Jack Segal wrote:<br>
>> Isolate the GEMs and restart flow one at a time.<br>
>><br>
>> Sent from my iPhone<br>
>><br>
>>> On Sep 28, 2021, at 11:39 AM, jboyd@jlab.org wrote:<br>
>>><br>
>>> To all,<br>
>>><br>
>>> Anu and I set up the gas distribution from the gas cylinders, to<br>
>>> through<br>
>>> the gas rack, and onto the GEM layers. We have been flushing and<br>
>>> flowing<br>
>>> gas. It seems that the gas loss rate is a bit more than what we would<br>
>>> expect given the flow rates that we have set. We are losing about a<br>
>>> bottle<br>
>>> a day for our 8 layers of GEMs. We expect that 1 bottle should be about<br>
>>> 3+<br>
>>> days.<br>
>>><br>
>>> Therefore, we are suspecting a leak somewhere, perhaps on the gas<br>
>>> distribution rack. I checked around the gas cylinders and the<br>
>>> connection<br>
>>> manifold and couldn't find any leaks (I did find one but I was able to<br>
>>> fix/seal it).<br>
>>><br>
>>> What should we do about getting the setup of the gas rack and possibly<br>
>>> the<br>
>>> cylinder/manifold setup leak tested and checked?<br>
>>><br>
>>> Thank you for the help.<br>
>>><br>
>>> Best,<br>
>>><br>
>>> John<br>
>>><br>
>>>> Hi Brad,<br>
>>>><br>
>>>> We discussed the SBS gas distribution in our meeting today. I will<br>
>>>> schedule a time to come over and install a Raspberry Pi in area for<br>
>>>> monitoring.<br>
>>>><br>
>>>> It looks like the rack accessory box has been relocated from the Hall<br>
>>>> to<br>
>>>> EEL 125, George is scheduling to connect the gas flow sensor chassis<br>
>>>> channels to the appropriate flow meters.<br>
>>>><br>
>>>> After these steps are completed, I'll send an email so Kondo's group<br>
>>>> can<br>
>>>> connect their detector gas lines to the output side of the gas flow<br>
>>>> sensor<br>
>>>> chassis and hook up the premix bottle to the regulator input.<br>
>>>><br>
>>>><br>
>>>><br>
>>>> Regards,<br>
>>>> Marc McMullen<br>
>>>> Sr. Instrumentation Designer<br>
>>>> Detector Support Group<br>
>>>> (757) 269-7738<br>
>>>><br>
>>>> From: Brad Sawatzky<<a href="mailto:brads@jlab.org">mailto:brads@jlab.org</a>><br>
>>>> Sent: Tuesday, September 21, 2021 10:51 PM<br>
>>>> To: Kondo Gnanvo<<a href="mailto:kagnanvo@jlab.org">mailto:kagnanvo@jlab.org</a>>; John<br>
>>>> Boyd<<a href="mailto:jboyd@jlab.org">mailto:jboyd@jlab.org</a>>; Rathnayake, Anuruddha<br>
>>>> (adr4zs)<mailto:adr4zs@virginia.edu>; Marc<br>
>>>> Mcmullen<<a href="mailto:mcmullen@jlab.org">mailto:mcmullen@jlab.org</a>><br>
>>>> Cc: dsg-halla_gem@jlab.org<mailto:dsg-halla_gem@jlab.org>; Jack<br>
>>>> Segal<<a href="mailto:segal@jlab.org">mailto:segal@jlab.org</a>><br>
>>>> Subject: [EXTERNAL] SBS gas distribution rack moved to EEL/125; help<br>
>>>> setting up?<br>
>>>><br>
>>>> Hi Marc, et al,<br>
>>>><br>
>>>> The SBS GEM gas distribution rack was recently moved to EEL/125.<br>
>>>> That is where the SBS GEM layers are being stored and worked on.<br>
>>>><br>
>>>> Marc, can your group support the GEM group in completing the setup<br>
>>>> of that gas system so they can start flowing gas to the layers in<br>
>>>> EEL/125? It will need to be reconnected to the network, some gas<br>
>>>> line<br>
>>>> 'jumpers' need to be run between the two sides of the rack, and lines<br>
>>>> need to be run from the rack to the GEM modules themselves. (I<br>
>>>> believe<br>
>>>> Jack fixed the issue with i2c multiplexing in that rack.)<br>
>>>><br>
>>>> I also moved a large spool of 1/4" poly into EEL/125 so fresh gas<br>
>>>> lines<br>
>>>> can be run. General consensus is to position the rack in the most<br>
>>>> convenient location in EEL/125 and run (relatively short) gas lines<br>
>>>> of<br>
>>>> the needed length to the individual GEM modules. We will cut a set<br>
>>>> of<br>
>>>> new (longer) gas lines for the final setup in the Hall in a couple<br>
>>>> months.<br>
>>>><br>
>>>> I'll be out of town for about a week, but I've discussed this with<br>
>>>> John<br>
>>>> Boyd and Anuruddha, and they are generally in either EEL/125 or /126.<br>
>>>><br>
>>>> -- Brad<br>
>>>><br>
>>>> --<br>
>>>> Brad Sawatzky (he/him), PhD <brads@jlab.org> -<>- Jefferson Lab/ Hall<br>
>>>> C/C111<br>
>>>> Ph: 757-269-5947 -<>- Fax: 757-269-5235 -<>- Pager:<br>
>>>> brads-page@jlab.org<br>
>>>> The most exciting phrase to hear in science, the one that heralds new<br>
>>>> discoveries, is not "Eureka!" but "That's funny..." -- Isaac<br>
>>>> Asimov<br>
>>>><br>
>>>><br>
>>><br>
>>><br>
><br>
> --<br>
> John(Jack) Segal<br>
> Halls A and C Spectrometer Support Manager<br>
> Thomas Jefferson National Accelerator Facility<br>
> 12000 Jefferson Avenue<br>
> Suite 12<br>
> Newport News, VA 23606-4486<br>
> Phone: (757) 269-7242<br>
> Cell: (757) 320-9977<br>
> _______________________________________________<br>
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