Campbell Scientific 107-L Temperature Probe - Manual (Page 20)

Model 107 Temperature Probe
Symptom: Temperature is reported as –86 (°C) or –53 (°F).
Verify the black wire is connected to the switched excitation channel as
specified by the measurement instruction.
Symptom: Incorrect temperature is reported.
Verify the multiplier and offset arguments in the measurement instructions
are correct for the desired units (Section 7.2, Datalogger Programming).
Check the cable for signs of damage and possible moisture intrusion.
Symptom: Unstable temperature is reported.
Most likely a result of electromagnetic interference. Try using the 60 or 50
Hz integration options, and/or increasing the settling time as described in
Section 8.3, Electrically Noisy Environments, and Section 8.4, Long Cable
Lengths. Make sure the clear shield wire is connected to datalogger
ground, and the datalogger is properly grounded.
9.2 Maintenance
The 107 probe requires minimal maintenance. For air temperature
measurements, check the radiation shield monthly to make sure it is clean and
free from debris. Periodically check cabling for signs of damage and possible
moisture intrusion.
9.3 Calibration
Calibration of the 107 probe is not necessary unless the application requires
removal of the thermistor interchangeability offset described in Section 6,
Specifications. If performing the one point calibration with an Edlog
datalogger, be aware of this precaution:
The value of the offset must be chosen so that the probe outputs the
temperature calculated by the polynomial, not the actual calibration
temperature. For example, a 107 probe placed in a calibration chamber at 0 °C
outputs 0.1 °C. An Offset argument of –0.16 is required for Edlog dataloggers
because at 0 °C, the polynomial calculates a temperature of –0.06 °C
(Appendix C, Conversion of Thermistor Resistance or Voltage Ratio to
Temperature).
10. Attributions and References
Santoprene ® is a registered trademark of Exxon Mobile Corporation.
EPA installation standard: Quality Assurance Handbook for Air Pollution
Measurement Systems – Volume IV: Meteorological Measurements Version 2.0
WMO standard: WMO No. 8, Seventh edition, 6 Aug 2008 Guide to
Meteorological Instruments and Methods of Observation
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