Temperature Correction; Barometric Corrections; Troubleshooting - Geokon 3400 Series Instruction Manual

6.2 Temperature Correction

The basic transducers are thermally compensated over normal temperatures. Temperature
correction is not required unless the temperature is changing rapidly. If this occurs, time should
be allowed for the transducer to reach thermal equilibrium.

6.3 Barometric Corrections

If the piezometers are unvented, they will respond directly to barometric fluctuations. If a
correction is required, it will be necessary to record the barometric pressure at the time of each
pressure reading. The change in Barometer (S
pressure change (P).

7. TROUBLESHOOTING

Maintenance and troubleshooting of Model 3400 Piezometer is confined to periodic checks of
cable connections. Once installed, the piezometers are often inaccessible and remedial action is
limited. Consult the following list of problems and possible solutions should difficulties arise.
Consult the factory for additional troubleshooting help.
Symptom: Piezometer Readings are Unstable
 Is there a source of electrical noise nearby? Most probable sources of electrical noise are
motors, generators, transformers, arc welders, and antennas. Make sure the shield drain wire
is connected to ground whether using a portable readout or datalogger.
 Does the readout work with another piezometer? If not, the readout may have a low battery
or be malfunctioning. Consult the appropriate readout manual for charging or troubleshooting
directions.
 Is the filter clogged? Remove piezo (if possible) and inspect.
Symptom: Piezometer Fails to Read
 Is the cable cut or crushed? This can be checked with an ohmmeter (voltage output sensors
only). If the resistance reads very high or infinite (megohms), a cut wire must be suspected.
If the resistance reads very low (<100Ω), a short in the cable is likely.
 Does the readout or datalogger work with another piezometer? If not, the readout or
datalogger may be malfunctioning. Consult the readout or datalogger manual for further
direction.
Symptom: Thermistor resistance is too high
 It is likely that there is an open circuit. Check all connections, terminals, and plugs. If a cut is
located in the cable, splice according to instructions in Section 4.7.
Symptom: Thermistor resistance is too low
 It is likely that there is a short. Check all connections, terminals, and plugs. If a short is
located in the cable, splice according to instructions in Section 4.7.
 Water may have penetrated the interior of the piezometer. There is no remedial action.
-S ), must be subtracted from the measured
1 0
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