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So the rotameter is set to 10 lpm; given that it's calibrated for nitrogen or air ( I forget which), it's flowing ~8 lpm of CO2.
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The MFC's been set to 7 lpm from the beginning of RGM. <br>
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So why is this flow rate of CO2 (15 lpm), the highest flow rate of CO2 that we've ever had, unable to reach, much less maintain a pressure of 0.14 iwc? It's been ~ 0.07 - 0.08 iwc.
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The increase to 10 lpm on the MFC only brought the pressure up to 0.08 iwc. Decreasing it to 5 lpm dropped the pressure to 0.07 iwc.
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So what's going on? Is the pressure gauge off? Has a leak developed? Has the bubbler shifted? Any ideas?</div>
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-Morgan<br>
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<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" style="font-size:11pt" color="#000000"><b>From:</b> Brian Eng <beng@jlab.org><br>
<b>Sent:</b> Sunday, December 12, 2021 1:25 AM<br>
<b>To:</b> Youri Sharabian <youris@jlab.org>; Marc Mcmullen <mcmullen@jlab.org><br>
<b>Cc:</b> Bob Miller <rmiller@jlab.org>; Morgan Cook IV <mcookiv@jlab.org>; dsg-hallb_htcc@jlab.org <dsg-hallb_htcc@jlab.org><br>
<b>Subject:</b> Re: HTCC CO2 pressure</font>
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I increased it to 10 lpm: <a href="https://logbooks.jlab.org/entry/3961354" id="LPlnk677599">https://logbooks.jlab.org/entry/3961354</a></div>
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This really should have gone via the on-call first rather than through emails though.</div>
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<div id="x_divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" color="#000000" style="font-size:11pt"><b>From:</b> Youri Sharabian <youris@jlab.org><br>
<b>Sent:</b> Sunday, December 12, 2021 1:02 AM<br>
<b>To:</b> Brian Eng <beng@jlab.org>; Marc Mcmullen <mcmullen@jlab.org><br>
<b>Cc:</b> Bob Miller <rmiller@jlab.org>; Morgan Cook IV <mcookiv@jlab.org><br>
<b>Subject:</b> HTCC CO2 pressure</font>
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Dear Brian and Marc,
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<div>The CO2 gas pressure in the HTCC is fluctuating between 0.04 iwc to 0.09 iwc. The gas flow rate currently is 7 l/min. Usually we use 10 l/min. Please increase the flow rate on the HTCC MFC to 10 l/min.</div>
<div>Usually at 10 l/min we have pressure in the HTCC of about 0.14 iwc to minimize effects of atmospheric pressure changes.</div>
<div>Please let me know if there are any problems.</div>
<div>Thank you.</div>
<div>Regards,</div>
Youri
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