Veeco MS40 Operation And Maintenance Manual page 43

Setting Crossover 2
The second "crossover", Crossover 2, is defined as the set point (the point
during pump down) where the unit switches from reverse mode testing
to direct mode testing. When the unit determines that the leak is smaller than
a "reverse flow" leak, the fine valve opens, the internal rough valve closes
and the unit "crosses over" into direct flow testing.
To reset the Crossover 2 parameter:
Vacuum Instrument Corp. Vacuum Instrument Corp.
2099 Ninth Avenue 2099 Ninth Avenue
Ronkonkoma, NY 11779 Ronkonkoma, NY 11779
631.737.0900 631.737.0900
1109-186-00 Rev. C
(mTorr) or millibar. One mTorr is equal to 1 x 10
millibar (mbar) is equal to 1 x 10
3 To alter the Crossover 1 set point, press either of the "SET"
arrow keys. The alphanumeric display will change either down
or up in correspondence with the number of key presses of the
left or right arrow keys. If a user tries to alter a setting outside
of its allowed range, the piezoelectric beeper within the unit will
emit a short sound. Once the Crossover 1 entry has been
altered, it will remain at the new setting until it is altered once
again. If testing is interrupted by an ERROR 01 or ERROR 05,
Crossover 1 has been set too high for this application and should
be lowered.
1 Press the "SELECT" keys until the green indicator next
to Crossover 2 is lit.
2 The Service Mode alphanumeric display will display a number
between 1 to 500 indicating the crossover set point in millitorr
(mTorr) or millibar. One mTorr is equal to 1 x 10
millibar (mbar) is equal to 1 x 10
3 To alter the Crossover 2 set point, press either of the "SET"
momentary switches. The alphanumeric display will change
either down or up in correspondence with the number of
key presses of the left or right arrow keys. If a user tries to alter
a setting outside of its allowed range, the piezoelectric beeper
within the unit will emit a short sound. Once the Crossover 2
entry has been altered, it will remain at the new setting until it is
altered once again. If testing is interrupted by an ERROR 02,
Crossover 2 has been set too high for this application and should
be lowered. It may also help to increase the "D1" parameter,
"Fine Crossover Delay."
-3
bar.
-3
bar.
2-26
-3
Torr. One
-3
Torr. One