From: Dan Long
Subject: TPM and Dewar Pressure
Date: Fri, 1 Apr 2016 09:05:28 -0600
Hi John and Tracy,
    I have seen mention in the logs recently of erroneous pressure =
readings from the TPM.  I=E2=80=99m not sure if the intent is to say =
that the readings are incorrect or simply bad.=20
    I can say from the plots that the readings appear correct and =
consistent.  The dewar on the sp1 side which reads around 25 PSI =
completes fills in less than 15 minutes.  The dewar on sp2 which reads =
less than 10 PSI takes more than 40 minutes to complete a fill.  The =
pressures show oscillations of a couple PSI and drop slightly during a =
fill and jump up a few PSI when the fill stops as the liquid remaining =
the line boils off, returning later to the oscillating steady state =
value.  All of this indicates the pressures recorded by the TPM are real =
and accurate.
   After the dewar on sp2 was put on it was around 20 PSI, but fell =
below 10 PSI when the first fill happened (and the lower dewar pressure =
alert went out).  It never recovered from that.  Usually if a pressure =
relief sticks open and drops the pressure, it slowly recovers over the =
next 12-24 hours.  This dewar didn=E2=80=99t.  I=E2=80=99m not sure =
replacing or adjusting the pressure relief will change anything here as =
it did hold a normal pressure prior to the first fill.  Please make a =
note of the dewar number when it gets changed today.  I think there may =
be something wrong with the dewar.
		Cheers,
		   Dan