Campbell Scientific 108-L Temperature Probe - Manual (Page 20)

Model 108 Temperature Probe
9.2 Maintenance
The 108 probe requires minimal maintenance. For air temperature
measurements, check the radiation shield monthly to make sure the radiation
shield is clean and free from debris. Periodically check cabling for signs of
damage and possible moisture intrusion.
9.3 Calibration
Calibration of the 108 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 108 probe placed in a calibration chamber at 0 °C
outputs 0.1 °C. An Offset argument of –0.15 is required for Edlog dataloggers
because at 0 °C, the polynomial calculates a temperature of –0.05 °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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