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How to shut down or vent a QTof or Synapt for a planned shutdown - WKB1047

Article number: 1047


Take QTof from an operate, vacuum state to vented and off.


  • MassLynx 4.1
  • Q-Tof Premier
  • LCT Premier
  • Synapt
  • Synapt G2
  • Synapt G2 S
  • Synapt G2 Si
  • Xevo QTof
  • Xevo G2 QTof
  • Xevo G2 S QTof
  • Xevo G2 XS QTof


  1. Put the QTof/Tof in full Standby. To do this, go to the Tune page and select Setup (top drop-down menu in the middle) and Instrument standby, or select the green Operate button in the bottom-right corner of the Tune page.
  2. Turn off all gasses and take a screen capture of the vacuum view to record the vacuum you had before you vented. To do this, go to the Tune page and select View (top drop-down menu second from the left).

  3. Select the Vacuum tab.

  4. Press CTRL+ALT+Print Screen, paste into Word Pad, and save.

  5. On S instruments (instruments with two rough pumps), close the source isolation valve (open the source enclosure door on the front of the instrument and close the isolation valve behind the sample cone).

  6. Vent the instrument using Vacuum (top drop-down menu in the middle on the Tune page) and select Vent.

  7. Once the system has vented, close MassLynx, ensuring that the LC is not pumping and there are no samples in the sample compartment.

  8. Power-off the MS (breakers on the back) starting with the EPC, then Electronics, then Vacuum on Synapt, QTof P or LCT P instruments. On Xevo instruments, flip only the bottom toggle switch at the bottom in the middle of the back of the Xevo. You may need to pull the switch out. Or you can unplug the Xevo. This is not necessary for the Synapt, QTof P, or LCT P.

  9. Power-off the LC, and then power-off the PC.

  10. Ensure that you leave the nitrogen connected at 100 psi to the instrument while it is vented.


You can essentially reverse the above procedure to pump the system down. Or see article #1049 - How to pump down my QTof 

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