User Manual

HMP60 Temperature and Relative Humidity Probe
18
3. Rinse the RH chip or dispose of the old RH chip.
4. Hold the sides of the rinsed or new chip and plug it in.
5. Screw on the protective cap.
9. Troubleshooting
Symptom: NAN, -9999, or 0 % relative humidity
1. Check that the sensor is wired to the correct analog input channels as
specified by the measurement instructions.
2. Verify the voltage range code for the single-ended measurement
instruction is correct for the datalogger type.
Symptom: Incorrect temperature or relative humidity
1. Verify the multiplier and offset parameters are correct for the desired units
(Tables 7-2 and 7-3).
10. References
AASC, 1985: The State Climatologist (1985) Publication of the American
Association of State Climatologists: Heights and Exposure Standards for
Sensors on Automated Weather Stations, v. 9, No. 4 October, 1985.
(www.stateclimate.org/publications/state-climatologist/NOAA-NCY-
SCBOOKS-SC77097/00000029.pdf)
EPA, 2008: Quality Assurance Handbook for Air Pollution Measurement
Systems, Vol. IV, Meteorological Measurements, Ver. 2.0, EPA-454/B-
08-002 (revised 2008).Office of Air Quality Planning and Standards,
Research Triangle Park, NC 27711.
Goff, J. A. and S. Gratch, 1946: Low-pressure properties of water from -160°
to 212°F, Trans. Amer. Soc. Heat. Vent. Eng., 51, 125-164.
Lowe, P. R., 1977: An approximating polynomial for the computation of
saturation vapor pressure, J. Appl. Meteor., 16, 100-103.
Meyer, S. J. and K. G. Hubbard, 1992: Nonfederal Automated Weather
Stations and Networks in the United States and Canada: A Preliminary
Survey, Bulletin Am. Meteor. Soc., 73, No. 4, 449-457.
Weiss, A., 1977: Algorithms for the calculation of moist air properties on a
hand calculator, Amer. Soc. Ag. Eng., 20, 1133-1136.
WMO, 2008. Guide to Meteorological Instruments and Methods of
Observation. World Meteorological Organization No. 8, 7th edition,
Geneva, Switzerland. Many of the manuals also include siting information
for relative humidity and temperature sensors.