Veeco MS40, Operation And Maintenance Manual, Page: 52 / 169

Calibration (Cal)
Pressing the CAL momentary switch activates the Calibration function.
The Calibration function of the leak detector is available only after the
Cal-Check procedure has been completed. After the Cal-Check cycle is
completed, when the actual leak rate measured by the unit is close to, but
not exactly the same as the internal leak rate standard, the Calibration
function may be used. Since the Calibration function adjusts the amplifier
gain, once initiated, the leak check of the Cal-Check function will now
conform to the internal leak rate standard. Note that consistent differences
greater than 15% may indicate an improperly tuned mass spectrometer or
a fault within the unit.
Tune
Pressing the TUNE momentary switch initiates an automatic tuning cycle.
During the tuning cycle, voltages applied to the mass spectrometer are
adjusted and optimized for peak sensitivity and performance. It is
recommended that the Tune function be used in conjunction with the Cal-
Check function. Since the Calibration function basically increases or
decreases the measurement gain of the unit, without the optimization of
the Tune function, the unit eventually may not be able to self-calibrate.
Vacuum Instrument Corp.
2099 Ninth Avenue
Ronkonkoma, NY 11779
631.737.0900
1109-186-00 Rev. C 2-35