Routine Maintenance

The instrument should be serviced approximately once per year.

O-rings

O-rings on the piston and anvil are essential to the accurate operation of the instrument and should be checked regularly for signs of wear or damage. The O-rings will wear, especially on the piston, and hence should be replaced regularly.

To check for O-ring leaks:

1. Tap the Maintenance view, then tap Advanced.
2. Select Allow calibration and tap Save.
3. Tap the Instrument view.

Changing calibrations will affect the performance of the instrument. The following steps do not change any calibrations. Pressing other buttons on the left side of the display may change calibrations.

4. Install an empty sample tube.
5. Enter a flow rate of 10 sccm and tap Set Flow Rate.
6. When pressure stabilizes, try to move the tube by hand. The O-rings should be replaced if the tube moves freely or the inlet or differential pressure vary by more than a few tenths of a cm H₂O.
7. Tap Stop Flow.
8. Tap the Maintenance view, then tap Advanced.
9. Deselect Allow calibration and tap Save.

Air Supply

Check that the cylinder has adequate pressure. Replace the cylinder when it is low. See Replace a Gas Cylinder .