PFC Operation Manual
3. Operation
825160-00, revision B
57
Operating the PFC with a Cryocoil, Continued
Step Action
Starting and cooling the system, continued
4.
Monitor the temperature indicated by COLDEST LIQUID (TC #9). This TC monitors the
t in the coldest part of the stack, and is a good indicator of
cooling when switching to COOL, this TC #9 should be 5 -10°C colder than
your desired cryocoil temperature. S
erature Versus Water Vapor
y take up to 60 minutes after going
temperature of the refrigeran
when to switch to COOL mode.
For quick
ee Cryosurface Temp
Partial Pressure on p
ote 1
: The unit may be operated in
initely in STANDBY.
ote 2:
If the unit is off for m
it ma
to Standby to
ling.
age 61.
def
N
N
ore than 12 hours,
attain complete precoo
in
5.
nce the unit has cooled to the desired temperature, switch it to COOL mode any time
fter the vacuum chamber has achieved vacuum. Most users switch to COOL at
rossover (when opening the high vacuum valve). The cryocoil will start capturing water
apor within 60 seconds.
ote 3:
Experiment with the cryopump to determine the shortest pumpdown time for a
articular application. The sooner the unit is switched to COOL, the faster the vacuum
hamber’s pumpdown time will be. However, if the cryocoil captures too much water,
e cryocoil’s apparent surface temperature will rise and limit the ultimate attainable base
ressure.
O
a
c
v
N
p
c
th
p
Continued next page
