[Dsg-rich] [Rich] rich air flow

[Brian Eng]

Valery,

It's actually the opposite, this cycling behavior is actually how it previously used to look (see overview plot). The "flat" flow/pressure is a relatively new phenomenon and it looks to be caused by the remnants of the hurricane coming through; lower ambient pressure causes higher differential pressure in the various gas volumes. Normally this shows up as the compressor cycling on/off less (see pre storm plots). Since the drop was so large it manifested as not even turning on.

The compressor used to get the tank to 120 psi, now it's only going to 110 psi, which is why the bottom part of the "spike" is lower.

However, the flow is basically the same as it was before: this points to the alarm and especially interlock values being to conservative or in many cases counter-productive as they'll shut off the detector and could result in a junk run prematurely.

Personally I would remove quite a few interlocks and loosen many of the alarms, but that decision should come from the detector exports.

----- Original Message -----
> From: "Valery Kubarovsky" <vpk at jlab.org>
> To: "Tyler Lemon" <tlemon at jlab.org>
> Cc: rich at jlab.org, "dsg-rich" <dsg-rich at jlab.org>, "Marco Mirazita" <Marco.Mirazita at lnf.infn.it>
> Sent: Sunday, October 14, 2018 11:02:15 AM
> Subject: Re: [Dsg-rich] [Rich]  rich air flow

> Hi Tyler,
> Look at zoom picture. Do you understand this behaviour?
> I mean this sharp drop of the pressure.
> Valery
> 
> 
> 
> 
> From: "Tyler Lemon" <tlemon at jlab.org>
> To: "Valery Kubarovsky" <vpk at jlab.org>
> Cc: "Marco Mirazita" <Marco.Mirazita at lnf.infn.it>, rich at jlab.org, "dsg-rich"
> <dsg-rich at jlab.org>
> Sent: Sunday, October 14, 2018 10:28:51 AM
> Subject: Re: [Rich] [Dsg-rich] rich air flow
> 
> 
> 
> Hi Valery,
> 
> I agree, the plot looks normal after 18:40 on October 13.
> 
> Attached is the same plot you shared, but with annotations showing the pressure
> measurement any time the value looked to be under 40 psi. The lowest it seems
> to have gotten was ~36 psi.
> 
> Also, the archiver doesn't ever show that the hardware interlock for the air
> pressure ever tripped. It's low limit is set to 35 psi.
> 
> Best regards,
> Tyler
> 
> 
> From: "Valery Kubarovsky" <vpk at jlab.org>
> To: "Tyler Lemon" <tlemon at jlab.org>
> Cc: "Mirazita Marco" <Marco.Mirazita at lnf.infn.it>, rich at jlab.org, "dsg-rich"
> <dsg-rich at jlab.org>
> Sent: Sunday, October 14, 2018 10:15:03 AM
> Subject: Re: [Rich] [Dsg-rich] rich air flow
> 
> Hi All,
> I got several calls yesterday evening and today night from CLAS12 shift about
> AIRPR1 alarm (currently minimum set to 35). See attached plot. I changed this
> limit to 30 for a moment. The plot looks not normal before Oct.13 18:40 in my
> view.
> Regards,
> Valery
-------------- next part --------------
A non-text attachment was scrubbed...
Name: post-storm.png
Type: image/png
Size: 43482 bytes
Desc: not available
URL: <https://mailman.jlab.org/pipermail/dsg-hallb_rich/attachments/20181014/bf705d3f/attachment-0006.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: pre-storm.png
Type: image/png
Size: 40622 bytes
Desc: not available
URL: <https://mailman.jlab.org/pipermail/dsg-hallb_rich/attachments/20181014/bf705d3f/attachment-0007.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: overview.png
Type: image/png
Size: 43794 bytes
Desc: not available
URL: <https://mailman.jlab.org/pipermail/dsg-hallb_rich/attachments/20181014/bf705d3f/attachment-0008.png>