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03102L-90 (A))
MODEL 03102L
WIND SENTRY ANEMOMETER
(WITH 4-20mA OUTPUTS)
INTRODUCTION
The Wind Sentry Anemometer measures horizontal wind speed. The
small size, simplicity, and corrosion resistant construction provide
a professional quality instrument at a modest cost. The cup wheel
shaft uses stainless steel precision instrument grade ball bearings
which are lubricated with a wide temperature range high quality
instrument oil. Standard bearings have light contacting seals to
exclude contamination and help retain lubricant for longer service life.
Cup wheel rotation produces an AC sine wave voltage signal with
frequency proportional to wind speed. Internal circuitry converts
the raw signal to 4 to 20 mA current output over the specified 0 to
50 m/s wind speed range.
The sensor mounts on standard 1 inch pipe, outside diameter
34 mm (1.34") and is supplied with a cross arm and junction box
for cable connections. Wind Sentry anemometers and wind vanes
are available separately with similar mounting and junction box.
INITIAL CHECK-OUT
When the Wind Sentry is unpacked, check it carefully for any signs
of shipping damage.
Place the cup wheel on the anemometer shaft and secure it by
tightening the set screw on the side of the hub. The instrument is
fully calibrated before shipment; however, it should be checked both
mechanically and electrically before installation. The cup wheel
should easily rotate 360° without friction.
INSTALLATION
Proper placement of the instrument is very important. Eddies from trees,
buildings, or other structures can greatly influence wind speed and
direction observations. To get meaningful data for most applications,
locate the instrument well above or upwind of such obstructions. As a
general rule, the air flow around a structure is disturbed to twice the
height of the structure upwind, six times the height downwind, and
twice the height of the structure above ground. For some applications
it may not be practical or necessary to meet these requirements.
Grounding the Wind Sentry is vitally important. Without proper
grounding, static electrical charge can build up during certain
atmospheric conditions and discharge through the transducers. This
discharge may cause erroneous signals or transducer failure. To
direct the discharge away from the transducers, housings in which the
transducers are mounted are made with a special anti-static plastic.
It is important that the mounting post be connected to a good earth
ground. There are two ways this may be accomplished. First, the
Wind Sentry may be mounted on a metal pipe which is connected
to earth ground. The mounting pipe should not be painted where the
Wind Sentry is mounted. Towers or masts set in concrete should be
connected to one or more grounding rods. If it is difficult to ground the
mounting post in this manner, the following method should be used.
Inside the junction box the screw labeled EARTH GND is connected
to the anti-static housings. This terminal should be connected to an
earth ground (Refer to wiring diagram).
To install the Wind Sentry, follow these steps:
1. MOUNT WIND SENTRY
a) Connect sensor cable to Wind Sentry junction box.
b) Place Wind Sentry on mounting post.
d) Tighten mounting post band clamp.
c) Connect sensor cable to measuring instrument as shown
in manual.
WIND SPEED SPECIFICATION SUMMARY
Range
0 to 50 m/s (112 mph)
Gust Survival 60 m/s (134 mph)
Sensor
Ø 12 cm cup wheel assembly
Ø 40 mm hemispherical cups
Turning Factor
75 cm (2.46 ft)
Distance Constant
2.3 m (7.5 ft.) for 63% recovery
Threshold Sensitivity
1.1 m/s (2.5 mph)
Transducer
Stationary coil
1300 Ohm nominal DC resistance
Output Signal
4-20 mA = 0-50 m/s
GENERAL
Power Requirement:
8 - 30 VDC
Operating Temperature:
-50 to 50°C (-58 to 122°F)
