Veeco MS40 Operation And Maintenance Manual page 25

CROSSOVER 1
CROSSOVER 2
DELAY
Vacuum Instrument Corp.
2099 Ninth Avenue
Ronkonkoma, NY 11779
631.737.0900
1109-186-00 Rev. C
The alphanumeric display indicates the programmed test port
pressure needed to crossover from the unit's gross testing
mode to reverse testing mode (when using the optional
external pump). If an external pump is not connected to the
unit, the crossover set point is the pressure needed to crossover
from the unit's roughing mode to the reverse testing mode.
This parameter may be altered while the unit is in either
Standard or Service Mode, by using the SET momentary
switches.
The alphanumeric display indicates the programmed test port
pressure needed to crossover from the unit's reverse testing
mode to its direct testing mode. This parameter may be
altered while the unit is in either Standard or Service Mode,
by using the SET momentary switches.
Seven delay settings are available and may be set while the unit is in
Standard mode:
D1/Fine (Direct) Crossover Delay: The time delay after
Crossover 2 has been reached and the onset of Direct testing.
The MS-40 stays in Reverse Flow during this time. The
factory default is 1.0 second; the parameter may be set between
0.1 to 999.9 seconds. Note that if the MS-40 is set for Manual
-10
ranging in the 10 range, the unit will remain in the
roughing state for the time set in D1 after Crossover 2
has been reached.
D2/Direct Rough Valve Close Delay: When Crossover 2
has been reached, the Rough valve will remain open for
this value and will then close. The factory default is 0.1
second; the parameter may be set between 0.1 to 999.9
seconds. If D2 is set to 999.9 seconds, the Rough valve
will remain open for the entire length of the test cycle.
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