Veeco MS40, Operation And Maintenance Manual, Page: 39 / 169

Vacuum Instrument Corp.
2099 Ninth Avenue
Ronkonkoma, NY 11779
631.737.0900
2.5 Operation With an External Pump
1 Connect the test object to the test port.
2 Press the green START pushbutton.
3 The external rough valve opens and the test object is evacuated.
4 As soon as roughing has commenced, the gross valve opens.
5 Leak testing begins in the 10
-4
std cc/sec range.
6 If a vacuum testing procedure is underway, spraying of the test
object with helium should now commence.
7 If a gross leak is detected the unit will range up to the
appropriate decade, while the test object continues to be pumped
down.
8 If no leak is found and the test port pressure has reached
Crossover 1, the unit will begin reverse mode testing.
The external rough valve and gross valve will close, the
internal rough valve will open and the leak detector will range
downward from the 10
-4
std cc/sec range to the 10
-9
std cc/sec
range.
9 If again a leak is not found and the test port pressure has reached
the Crossover 2 setting, the internal rough valve closes, the fine
valve opens and the unit ranges to the 10
-10
std cc/sec range.
10 The unit will continue to test at this level unless a leak is found
or until the VENT pushbutton is pressed.
11 When leak testing has been completed, pressing and holding the
VENT pushbutton (the default is for 0.5 second or may be
programmed by the user - the D3 time interval) closes all
vacuum system valves except for the fore-line valve, opens the
vent valve and vents the test port and test object.
1109-186-00 Rev. C 2-22