NovaLynx Corporation
255-212D
Page 5
December 2020
4
NATIONAL WEATHER SERVICE RECOMMENDATIONS
The following information is excerpted from
National Weather Service Observing Handbook No. 2
(July 1989). The complete manual can be downloaded here:
https://novalynx.com/manuals/coophandbook2.pdf
1.5.1 RESETTING INSTRUMENTS
Reset the maximum and minimum thermometers only once each 24 hours,
immediately after they have been read. Non-recording rain gages
should be emptied after being read only once each 24 hours.
Thermometers and gages should be reset only at the time of
observation agreed to with the NWS representative. Instruments may be
read at intermediate times, but they should not be reset.
5.3.6.1.3 RECORDING THERMOMETERS
Any recording thermometer with an immersible sensing element may be
used. Examples are electrical resistance, mercury-in-steel, and gas-
filled steel elements. The line connecting the thermometer to the
recorder should be long enough to permit installation of the recorder
where it will not cast a shadow on the pan, and more than four feet
from any instrument. It should be in a low housing along a fence in
the northern half of the enclosure (northern hemisphere). The
thermometer should be mounted on an adjustable float mechanism in a
horizontal position. It must be shielded from direct solar and sky
radiation and from possible physical damage. The float mechanism
should be adjusted to support the thermometer about 1/4 inch beneath
the surface of the water near the center of the pan.
5.3.6.3 ACCURACY CHECKS
Check the accuracy of the water temperature readings once a month
when the pan is cleaned…
5
INSTALLATION
The
255-212D Min/Max Thermometer
consists of two main parts, the digital display unit and the
probe, which is mounted on a floating/submersible base. The display unit is weather-proof, but will last
longer if some protection from the weather is provided.
Suggestion: Provide a small enclosure mounted
on a short post to house the display and protect it from sun and rain. Make sure the post/enclosure will
not cast a shadow on the evaporation pan.
