
16
5. TROUBLESHOOTING
Maintenance and troubleshooting of vibrating wire piezometers is confined to periodic checks of
cable connections and maintenance of terminals. The transducers themselves are sealed and are
not user serviceable.
Gages should not be opened in the field.
Should difficulties arise, consult the following list of problems and possible solutions. For
additional troubleshooting and support, contact Geokon.
Symptom: Thermistor resistance is too high:
Is there an open circuit? Check all connections, terminals, and plugs. If a cut is located in the
cable, splice according to instructions in Section 2.4.
Symptom: Thermistor resistance is too low:
Is there a short? Check all connections, terminals, and plugs. If a short is located in the cable,
splice according to instructions in Section 2.4.
Water may have penetrated the interior of the tilt sensor. There is no remedial action.
Symptom: Tiltmeter Readings are Unstable:
Is the readout box position set correctly? If using a datalogger to record readings
automatically, are the swept frequency excitation settings correct?
Is there a source of electrical noise nearby? Most probable sources of electrical noise are
motors, generators, and antennas. Make sure the shield drain wire is connected to ground.
Does the readout work with another tilt sensor? If not, the readout may have a low battery or
be malfunctioning.
Symptom: Tiltmeter Fails to Read:
Is the cable cut or crushed? This can be checked with an ohmmeter. Table 1 shows the
expected resistance for the various wire combinations; Table 2 is provided for the customer
to fill in the actual resistance found. Cable resistance is approximately 14.7
Ω
per 1000 feet
(48.5
Ω
per km) of 22 AWG wire. Multiply this factor by two to account for both directions.
If the resistance reads very high or infinite (megohms), a cut wire must be suspected. If the
resistance reads very low (
<
100
Ω
), a short in the cable is likely.
Does the readout or datalogger work with another tilt sensor? If not, the readout or datalogger
may be malfunctioning.
Summary of Contents for 6350
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