Problems That Occur On E5083 Unit Only - Agilent Technologies E5080 Series User Manual

2
Operation

Problems that occur on E5083 unit only

Problem
Slow helium leak to
atmosphere
Fast helium leak to
atmosphere
Failed gas heater
resistive element,
open circuit.
Failed thermal sensor
- open circuit
Cooler failed or low
efficiency.
Disconnected thermal
sensor cable
Disconnected gas
heater
20
As detected by E5083
Falling helium level.
Apparent increase in
cooler efficiency.
Falling helium level, quite
soon.
Inability to maintain
pressure
Hardware failure of gas
heater
Thermal hardware error.
Pressure rises
Thermal reading may rise
Thermal sensor
hardware failure is
detected
Hardware failure of gas
heater
Alarm result Comments
Low helium level After a period of days or
weeks.
but not immediately.
Pressure may be
correct, initially. Gas heater activity may well
appear to be normal but in
fact will be slightly more
active.
Low helium level, Period of hours or few days.
sooner rather than
later.
pressure likely to fall
Gas heater likely to be on
below alarm point
100% time.
Heater hardware Within three seconds, if and
failure is detected only if the heater should be
active
status shows
" ERROR "
Thermal hardware Within three seconds if and
failure is detected only if the thermal sensor
should be active
Over pressure alarm Status changes to " ERROR "
may be tripped if rise when any one of the factors
is sufficient. over-steps the trip level.
Over temperature Gas heater will usually be off
may be tripped 100% time, if cooler has
failed
Thermal sensor Within three seconds
hardware failure is
indicated.
Heater hardware Within three seconds after
failure is indicated. E5083 commands gas heater
" ON "
E5080 Series Cryogen Monitor User Guide