Base of shelter is set 5.5' above ground level (ground is
covered with pea gravel);
louvered on all sides; double roof; always located in direct sunlight; door
always
opens in the direction where sun light will never enter shelter; Pierce Station
is located
north of 23° 30' north latitude, therefore, shelter is situated to face north.
(Stations south of 23° 30' south latitude must face south, and stations between
these
2 latitudes must be mounted on a rotating base to accommodate changing sun
angles);
Shelter painted white to prevent excess heat absorption.
Instruments found in Weather Shelter include...
* U.S.N.W.S. Official Maximum and Minimum Air
Thermometers
* Soil Temperature Gauge
* Wet and Dry Bulb Thermometers (psychometric readings)
* Hygrothermograph
Within the
weather
shelter is the thermograph, max and min thermometers, soil temperature sensor
(in white box beneath shelter), dry and wet bulb thermometers, and an aspirating
motor (top right side of shelter on the outside of unit).
Beneath the shelter is a box protecting the soil temperature gauge from direct
solar radiation. The temperature tube is insulated to avoid false readings.
Above is a closer look at what is contained within the weather shelter. The top
horizontal
thermometer is the min. The one beneath it is the max. The round dial on the
back wall
is the soil temperature gauge. Front and center is the thermograph. The top pen
records
temperature continuously, the bottom pen measures relative humidity
continuously. On the
right I have devised a system for measuring RH. The two dangling thermometers
(side-by-side)
hang in front of an orifice which is the opposite end of a tube connected to the
aspirating motor
(via a pre-heater hose to a car) connected outside of the shelter (outside to
radiate heat from the
motor away from the measuring devices.) I ran an underground conduit to the
weather shelter from
a nearby electrical source and put a switch to activate the aspirator inside the
shelter. The cylindrical
chrome device to the far left is the *psychrometer which has a built in motor
which draws air past its
two thermometers. The switch operates both devices simultaneously, and the result
is a high level of accuracy.
Extra pen ink and distilled water can be seen on the lower right hand corner.
