Model HC2S3 Temperature and Relative Humidity Probe
15
The Teflon filter is recommended when the sensor is installed in close
proximity to the ocean or other bodies of salt water. A coating of salt (mostly
NaCl) may build up on the radiation shield, sensor, filter and even the sensors.
A buildup of salt on the filter or sensors will delay or destroy the response to
atmospheric humidity.
Long term exposure of the relative humidity sensor to certain chemicals and
gases may affect the characteristics of the sensor and shorten its life. The
resistance of the sensor depends strongly on the temperature and humidity
conditions and the length of the pollutant influence.
If the sensor is damaged, an updated HC2A-S3 sensor can be used as a
replacement sensor head. Refer to
information.
The sensor should be calibrated annually. Please obtain an RMA number
before returning the HC2S3 to Campbell Scientific for calibration. Please refer
sections at the beginning of the manual.
10. Attributions and References
Santoprene
®
is a registered trademark of Exxon Mobile Corporation.
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, 2000:
Meteorological Monitoring Guidance for Regulatory Modeling
Applications
, EPA-454/R-99-005. Office of Air Quality Planning and
Standards, Research Triangle Park, North Carolina 27711.
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.
