[Dsg-mvt] [New Logentry] Follow-up Re: issue with flowmeter reading

[beng at jlab.org]

Logentry Text:
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There is some logic to the flow setpoints based on the tank pressure. Currently it is as follows (going from memory and not looking at the code) in automatic mode.

If pressure is < 10 psi: total setpoint is multiplied by 1.5 the demand setpoint (to increase tank pressure)
If pressure is > 15 psi: total setpoint is multiplied by 0.5 the demand setpoint (to decrease tank pressure)
If pressure is > 25 psi: total setpoint is multiplied by 0.0 the demand setpoint (as a safety to stop flow)

>From the screenshot (entry 3498980) it looks like the multiplier value might be optimal as MIX1_Ar_FLOW_SET became to low to actually flow, i.e. 40 sccm is below the minimum (entry 3492865) of 41.7 sccm.
I'm not sure why MIX2_Ar_FLOW_FRAC is alarming though.

The easiest/fastest fix would be to increase the demand flow for Mix 1 slightly (by increasing demand on the FMT, FTT, or both) such that the Ar flow goes above the MFC minimum.

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