43
6. TROUBLESHOOTING
Listed below are a few commonly experienced problems and remedial action. Contact the factory
should a problem arise not explained herein or additional information be needed.
Symptom: Unit will not respond to communications:
Wrong COM port selected in LogView. See LogView manual
If RS-232 or RS-485 communications are being used, the internal batteries of the datalogger
may be low, dead, or inserted incorrectly. Replace/check the batteries. (Units manufactured
before September 2018 were supplied with an aluminum battery holder, which may need
adjusting; refer to Appendix I.)
If RS-485 communications is being used, the
<ENTER>,<ENTER>,
#
,
datalogger address
,
<
ENTER>
key sequence is not being sent. Refer to Appendix F, “Networking” for further
information.
Symptom: Vibrating wire gauge measurement reads -999999.0:
Using an ohmmeter, check connections to the vibrating wire gauge leads (Usually the red and
black conductors, or pins A and B on a 10-pin bulkhead connector.) Resistance should be
between 90 and 180 ohms. Remember to add the cable resistance at approximately 14.7
Ω
per
1000 ft. or 48.5
Ω
per km at 20 °C. Multiply this factor by two to account for both directions.
If the resistance is very high or infinite (megohms), the cable is probably broken or cut. If the
resistance is very low (<20
Ω
), the gauge conductors may be shorted.
Check the datalogger with another gauge. If it reads okay, the datalogger may be
malfunctioning.
Check that the proper gauge type is selected and connected properly. (See Table 1 in Section
3.1 and Table 3 in Section 4.8.)
Symptom: Gauge measurement (analog or vibrating wire) reads -999999.9:
A mathematical overrange has occurred. Check the magnitude of the reading, zero reading,
multiplier, and offset. The result must be in the range of 1.0
×
10
-7
to 1.0
×
10
7
.
Symptom: Vibrating wire gauge reading is unstable:
Is there a source of electrical noise nearby? Likely candidates are generators, motors, arc
welding equipment, high voltage lines, etc. If possible, move the datalogger and transducer
cable away from the power lines or electrical equipment.
Check if the proper gauge type is selected. (See Table 1 in Section 3.1 and Table 3 in Section
4.8.)
Symptom: Thermistor measurement shows -99.9 degrees Celsius:
Indicates open circuit to thermistor leads. Check connections from datalogger to thermistor
leads. If okay, check thermistor with ohmmeter. Appendix E, “Thermistor Temperature
Derivation” details the resistance versus temperature relationship. It should read between
10K ohms and 2.4K ohms (0 to +30
°
C). If thermistor checks out okay, consult the factory to
schedule repair of unit.