Veeco MS40, Operation And Maintenance Manual, Page: 41 / 169

Vacuum Instrument Corp.
2099 Ninth Avenue
Ronkonkoma, NY 11779
631.737.0900
High Sensitivity Sniff Testing
High Sensitivity Sniff Testing is similar to the sniff testing procedure
(above) except:
1 The sniffer probe is connected to the top test port
instead of a dedicated “sniff” port on the back of the machine.
2 Provides for greater sensitivity during testing.
3 Operates in Reverse flow mode rather than the Sniffing mode.
The procedure for High Sensitivity Sniff Testing is as follows:
1 Remove the KF25 blank that covers the test port. Install the
sniffer assembly with the KF25 adapter.
2 Make sure that the MS-40 is in the Standard mode, not the Sniff
mode.
3 Select either Automatic or Manual ranging. If Manual ranging
is chosen, set the MS-40 for the 10
-9
range or higher; do not set
it for the 10
-10
range. In either case, the unit will be able to test
leaks within the 10
-4
to 10
-9
std cc/sec range.
4 Press the START pushbutton. If the unit is set for Automatic
ranging, it will range down to the level of the ambient helium.
This background may be “zeroed out” for high sensitivity
sniffing by pressing the “ZERO” pushbutton).
5 The unit is now ready for testing. Using the probe, examine the
test object for leaks.
NOTE:
The MS-40 will remain in the Reverse flow mode when sniffing
through the test port. The pressure in the sniffer probe will prevent
the unit from crossing over into the Direct flow mode.
1109-186-00 Rev. C 2-24