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The weather station is divided into sensors and the CR10 datalogger for trouble shooting purposes.
Appendix B contains sensor specifications and schematics.
5.1 SENSOR TROUBLE SHOOTING
The *6 Mode is used to display current sensor
readings (Section 2.7). If an individual sensor
reading is incorrect, the sensor circuit should be
checked with a VOM (Volt/OHM meter).
Appendix B provides wiring schematics of each
sensor. All sensors, except for the rain gage,
have a measurable resistance. Infinite
resistance indicates an open circuit.
NOTE: DO NOT connect an Ohm meter to
the temperature and relative humidity
probe.
Wind Speed
The resistance of the coil measured between
pins 1 and 2 should be between 1100 - 1400
ohms. Infinite resistance indicates the coil is
broken; zero resistance indicates a short. Open
the sensor and check for moisture or pinched
wires.
Wind Direction
The resistance between pins 1 and 2 of the
windvane varies from 1 - 11 kohms for a 0-355o
direction. A 5o open or "dead" band exists at
355o. The wiper in the potentiometer is most
likely damaged if infinite resistance is
measured.
The resistance between pins 1 and 3 should
always be 10K ohms. Infinite resistance
indicates the potentiometer is open and should
be replaced.
Rain Gage
The rain gage has a reed switch that closes as
the bucket tips. Connect the ohm meter to pins
1 and 2 and tip the bucket very slowly. The
meter display will flutter momentarily as the
switch contacts close then reopen. Lack of
contact indicates the reed switch should be
replaced.
SECTION 5. TROUBLE SHOOTING
Solar Radiation
The solar radiation sensor should measure
between 60 and 100 ohms when the sensor is
dark. Check for an open circuit.
Temperature and Relative Humidity (RH)
If you are experiencing problems with the
temperature and relative humidity probe,
consider the following:
1. Are both the temperature AND the relative
humidity readings bad? If so, make sure
the radiation shield and sensor endcap are
free from debris.
2. Is just the temperature reading bad?
Again, make sure the radiation shield and
sensor endcap are free from debris.
3. Is just the relative humidity reading bad? In
this case, the probe needs to be
recalibrated. (Contact CSI if facilities to
recalibrate are unavailable.)
4. If 1,2 and 3 prove to be ineffective, contact
CSI.
5.2 DATALOGGER TROUBLE
SHOOTING
The CR10 (1) measures the sensors, (2)
converts the measurements to engineering
units, (3) processes the values over a time
interval and (4) stores the processed result. If
stored data is incorrect, evaluate the current
measurements directly using the CR10KD
Keyboard Display (Section 2.7).
False battery readings of 9 to 10 volts can be
observed in the *6 Mode (*6A, Section 2.7) if
the battery voltage falls to 8 volts. If the sensor
readings are unreasonable, yet the sensors
check out according to Section 5.1, measure
the battery voltage independently (Figures 2.5-1
and 2.5-2). Check the charging system if the
system has one.
5-1
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