Campbell Scientific PVS4100/4120/4150 Portable Automatic Samplers - Manual (Page 39)

4-1
Section 4. Maintenance
The following maintenance procedure should be performed at regular
intervals:
4.1 General Maintenance
1. Disconnect power.
2. Open metering chamber by removing wing nuts and chamber cover.
3. Clean volume control tube and level sensing probe with mild detergent.
Alternatively, exchange tube and probe with clean set. Do not use any
cleaner which may be harmful to the metering chamber cover. Do not use
solvents such as acetone, benzene, carbon tetrachloride or lacquer thinners.
Grease and oil may be removed with kerosene or aliphatic naphtha (non-
aromatic).
4. Check and clean O-rings in metering chamber cover.
Replace if damaged, worn or brittle.
5. Clean metering chamber using mild detergent.
Do not use any cleaner which may be harmful to the clear acrylic, (e.g.
petrochemical solvents, as noted above.) Do not use abrasives or
“scouring” compounds.
6. Check discharge tubing for wear and replace as necessary.
7. Check pinch valve to ensure free movement.
8. If possible, run sampler through several sampling sequences in clean
water.
4.2 Testing System Vacuum
Using the (optional) built-in pressure / vacuum gauge, take a reading to ensure
system has no leaks. Optimal pressure is above 28 psi. Optimal vacuum should
be 12 psi or better.
If the system is not performing at its peak, try the following:
1. Check intake hose for leaks/kinks.
2. Check discharge tube, ensure it has no leaks and is in good shape.
3. Check all fittings to ensure they are tight.
4. Make sure when tightening and loosening the gland nuts on the top of the
metering chamber that the bottom nut is held secure and does not move on
the cover. Ensure the top nut is securely tightened, and use a wrench if
necessary.