John, Bubba

The 3 IFO storage containers are under a constant nitrogen gas purge taken from the CP2 LN2 storage dewar boiloff.

The dewpoint sensors are showing some erratic behavior so Bubba and I investigated. We have determined that the pressure regulators supplied with each storage container are not operating correctly at such low inlet pressures (< a few psi ) and actually alternately shut the flow off and then as the pressure builds they again allow flow.  The glitches shown do not reflect the air quality in the storage can but only at the sensor itself - which is directly exposed to LVEA ambient conditions on it's exhaust port.

We will replace these regulators with simple rotameters in the next week or two.