Geokon 4580, Инструкция по эксплуатации

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15
6. TROUBLESHOOTING
Maintenance and troubleshooting of vibrating wire pressure transducers is confined to periodic
checks of cable connections and maintenance of terminals. The transducers themselves are
sealed and are not user serviceable. Gauges 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: Transducer fails to give a reading
3) Is the cable cut or crushed? This can be checked with an ohmmeter. Nominal resistance
between the two gauge leads (usually red and black leads) is 180 Ω , ± 20 Ω . For long cables a
correction can be applied, equal to approximately 14.7 Ω per one thousand feet (48.5Ω per
km). Multiply this factor by two to account for both directions.

. If the resistance reads infinite, or very high (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 transducer? If not, the readout or
datalogger may be malfunctioning. Consult the readout or datalogger manual for further
direction.

Has the transducer been overranged or shocked? Contact the factory for further direction.
Symptom: Transducer reading unstable

Is the readout box position set correctly? If using a datalogger to record readings
automatically are the swept frequency excitation settings correct? Try reading the transducer
on a different readout position. For instance, channel A of the GK-404 and GK-405 might be
able to read the sensor. To convert the Channel A period display to digits, use Equation 1 in
Section 4.1.

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. If using the GK-404
or GK-405 readout box connect the clip with the blue boot to the shield drain wire.

Does the readout work with another transducer? If not, the readout may have a low battery or
be malfunctioning. Consult the appropriate readout manual for charging or troubleshooting
directions.

Has the transducer been dropped or otherwise shocked? If so, it may experience a large zero
shift or be damaged.

Has the pressure chamber been de-aired? See Section 2.2.3 for instructions.

Has the moisture trap seal screw been removed?
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 2.3.
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 2.3.

Water may have penetrated the interior of the transducer. There is no remedial action.