Campbell Scientific PVS4100/4120/4150 Portable Automatic Samplers - Manual (Page 37)

Section 3. Operation
3-7
SAMPLER WILL NOT TAKE TIMED SAMPLE:
a) Sampler controller defective.
SAMPLER WILL NOT INITIATE FROM AN EXTERNAL
CONTACT: Check wiring from terminal strip to sampler controller
plug. (Terminals 12 & 13)
a) Sampler controller is defective.
b) Sampler controller not programmed for External Contact input.
PUMP IS OPERATING, NO AIR PURGE OF INTAKE LINE: Check for
blockage of intake hose by removing hose from the metering chamber volume
control tube. Initiate manual sample and check for pressure/vacuum throughout
sample cycle.
a) If pressure/vacuum is present throughout sample cycle, intake hose is
plugged.
b) Pinch valve may not be closing the discharge hose with sufficient force
to ensure an adequate seal. Increase tension by tightening the lock nuts on
the pinch valve tension springs and/or replace discharge hose.
c) Check for disconnected air lines from pump to metering chamber.
d) Check for loose gland nuts.
e) Pump flapper valves defective.
PURGE CYCLE OPERATIVE, NO SUCTION: Pinch valve may not be
closing the discharge hose with sufficient force to ensure an adequate seal.
Increase tension by tightening the lock nuts on the pinch valve tension springs
and/or replace discharge hose.
a) Check air lines, metering chamber O-rings and fittings for leakage.
b) Solenoid valve clogged or not working.
c) Intake tube, not below water level.
SAMPLER HAS HAD AN “EXTERNAL STOP”: Contact not supplied via
terminal block.
a) Sample container Full Level Probe has been triggered.
LEVEL SENSING PROBE INOPERATIVE: Check wire contact
connections on volume control tube and level sensing probe. Check wiring to
the sampler controller plug.
a) Sampler controller defective
b) Coating on probe and/or Volume Control Tube.