<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<style type="text/css" style="display:none;"> P {margin-top:0;margin-bottom:0;} </style>
</head>
<body dir="ltr">
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
The flow through the system (rotameters and flow meters) should be multiplied by ~1.1375 to account for the fact that the gas being flown is 70/30 Ar/CO2</div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
<br>
</div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
So the actual flow will be higher than indicated by the readouts.</div>
<div>
<div id="appendonsend"></div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
<br>
</div>
<hr tabindex="-1" style="display:inline-block; width:98%">
<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" color="#000000" style="font-size:11pt"><b>From:</b> Dsg-halla_gem <dsg-halla_gem-bounces@jlab.org> on behalf of Jack Segal <segal@jlab.org><br>
<b>Sent:</b> Tuesday, September 28, 2021 1:22 PM<br>
<b>To:</b> jboyd@jlab.org <jboyd@jlab.org><br>
<b>Cc:</b> dsg-halla_gem@jlab.org <dsg-halla_gem@jlab.org><br>
<b>Subject:</b> Re: [Dsg-halla_gem] [EXTERNAL] SBS gas distribution rack moved to EEL/125; help setting up?</font>
<div> </div>
</div>
<div class="BodyFragment"><font size="2"><span style="font-size:11pt">
<div class="PlainText"> I turned off all the flow meters. Turned them on a section at a time. I think you<br>
are just using a lot of gas. I'm not sure how accurate those visual meters 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 through<br>
>> the gas rack, and onto the GEM layers. We have been flushing and 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 bottle<br>
>> a day for our 8 layers of GEMs. We expect that 1 bottle should be about 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 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 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 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 can<br>
>>> connect their detector gas lines to the output side of the gas flow 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 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 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 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 of<br>
>>> the needed length to the individual GEM modules. We will cut a set 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 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: 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 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>
Dsg-halla_gem mailing list<br>
Dsg-halla_gem@jlab.org<br>
<a href="https://mailman.jlab.org/mailman/listinfo/dsg-halla_gem">https://mailman.jlab.org/mailman/listinfo/dsg-halla_gem</a><br>
</div>
</span></font></div>
</div>
</body>
</html>