Ulvac CRYOPUMP CRYO-U Series Instruction Manual page 50

CRYO-U Cryopump Instruction Manual
®
limit value at which the cryopump can res
v v alue which controls the cryopanel temperature not to exceed 20K is used as the alue which controls the cryopanel temperature not to exceed 20K is used as the
maximum allowable crossover pressure. maximum allowable crossover pressure.
The maximum quantity of sucked gas which is instantaneously processable varies with The maximum quantity of sucked gas which is instantaneously processable varies with
the heat load on the cryopump and the quantity of the gas condensed in the cryopump. the heat load on the cryopump and the quantity of the gas condensed in the cryopump.
(Refer to Table 5-2.) (Refer to Table 5-2.)
Tab Tab le 5-2 le 5-2 Maximum Quantity of Sucked Gas Processable by Cryopump Maximum Quantity of Sucked Gas Processable by Cryopump
Model Model
CRYO-U18H
[Example] When U16P is used and the
allowable cros sover pressure
Maximum allowable crossover
pressure (Pa)
In order to restrict the stored quantity of gas and extend the regeneration cycle, it is
rec ommended to
(Guideline Quantity to the Air) (Guideline Quantity to the Air)
is calculated as follows
† For reference †
control the actual crossover pressure to 40Pa or less.
ULVAC CRYOGENICS INCORPORATED
s tore the evacuation performanc tore the evacuation performanc
Maximum quantity of sucked gas spontaneously Maximum quantity of sucked gas spontaneously
processable (Pa•L) processable (Pa•L)
Limit quantity for the tempera Limit quantity for the tempera
vacuum chamber volume is 100L, the maximu
53200 （Pa･L）
≦
1 00（L）
e. Normally, a e. Normally, a
ture of 20K or less ture of 20K or less
53200
= 532 （Pa）
m
5-5