
Page2
aspecial anti-staticplastic.It isimportant thatthemounting postbe
connected to a good earth ground. There are two ways this may
beaccomplished.First,theWindMonitormaybemountedonametal
pipewhich isconnectedtoearthground. Themounting pipeshould
not be painted where the Wind Monitor 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
boxthe terminallabeled EARTHGNDisinternallyconnectedtothe
anti-static mounting post. This terminal should be connected to an
earth ground (Refer to wiring diagram).
Initial installation is most easily done with two people; one to adjust
the instrument position and the other to observe the indicating
device. After initial installation, the instrument can be removed and
returned to its mounting without re-aligning the vane since the
orientation ring preserves the wind direction reference. Install the
Wind Monitor following these steps:
1.MOUNT WIND MONITOR
a) Place orientation ring on mounting post. Do Not tighten
band clamp yet. Orientation ring may be omitted when
portable tripod is used.
b) Place Wind Monitor on mounting post. Do Not tighten band
clamp yet.
2.CONNECTSENSORCABLE.
a) Refer to wiring diagram located at back of manual.
3. ALIGN VANE
a) Connect instrument to indicator.
b) Choose a known wind direction reference point on the
horizon.
c) Sighting down instrument centerline, point nose cone at
reference point on horizon.
d) While holding vane in position, slowly turn base until
indicator shows proper value.
e) Tighten mounting post band clamp.
f) Engage orientation ring indexing pin in notch at instrument
base.
g) Tighten orientation ring band clamp.
CALIBRATION
The Wind Monitor is fully calibrated before shipment and should
require no adjustments. Recalibration may be necessary after
some maintenance operations. Periodic calibration checks are
desirable and may be necessary where the instrument is used in
programs which require auditing of sensor performance.
Accurate wind direction calibration requires a Model 18112 Vane
AngleBenchStand.Beginby connecting the instrument to a signal
conditioning circuit which has some method of indicating a wind
direction value. This may be a display which shows wind direction
values in angular degrees or simply a voltmeter monitoring the
output. Orient the base so the junction box faces due south.
Visually align the vane with the crossmarkings and observe the
indicator output. If the vane position and indicator do not agree
within 5°, it may be necessary to adjust the potentiometer coupling
inside the main housing. Details for making this adjustment appear
intheMAINTENANCE,POTENTIOMETERREPLACEMENT,outline,
step 7.
It is important to note that, while the sensor mechanically rotates
through 360°, the full scale wind direction signal from the signal
conditioning occurs at 355°. The signal conditioning electronics
must be adjusted accordingly. For example, in a circuit where 0 to
1.000 VDC represents 0° to 360°, the output must be adjusted for
0.986VDCwhentheinstrumentisat355°.(355°/360°X1.000volts
= 0.986 volts).
Wind speed calibration is determined by propeller pitch and the
output characteristics of the transducer. The calibration formula
relating propeller rpm to wind speed is shown below. Standard
accuracy is ±0.3 m/s (0.6 mph). For greater accuracy, the sensor
must be individually calibrated in comparison with a wind speed
standard. Contact the factory or your supplier to schedule a NIST
(National Institute of Standards & Technology) traceable wind
tunnel calibration in our facility.
To calibrate wind system electronics, temporarily remove the
propeller and connect an Anemometer Drive to the propeller shaft.
Applythecalibrationformulatothecalibratingmotorrpmandadjust
theelectronics fortheproper value.For example,withthe propeller
shaft turning at 3600 rpm adjust an indicator to display 17.6 m/s
[3600 rpm x .0049 (m/s)/rpm = 17.6 m/s].
Details on checking bearing torque, which affects wind speed and
direction threshold, appear in the following section.
CALIBRATION FORMULAS
Model 05103V Wind Monitor w / 08234 Propeller
WIND SPEED vs PROPELLER RPM
05103VM m/s = 0.00490 x rpm
05103VN knots = 0.00952 x rpm
05103VP mph = 0.01096 x rpm
05103VK km/h = 0.01764 x rpm
WIND SPEED vs 0-1 VDC OUTPUT
05103VM m/s = mV x 0.05
05103VN knots = mV x 0.10
05103VP mph = mV x 0.10
05103VK km/h = mV x 0.20
WIND DIRECTION vs 0-1 VDC OUTPUT
DEGREES = mV x 0.36
MAINTENANCE
Given proper care, the Wind Monitor should provide years of
service. The only components likely to need replacement due to
normal wear are the precision ball bearings and the wind direction
potentiometer. Only a qualified instrument technician should per-
form the replacement. If service facilities are not available, return
the instrument to the company. Refer to the drawings to become
familiar with part names and locations. The asterisk * which
appearsinthefollowingoutlinesisareminderthatmaximumtorque
on all set screws is 80 oz-in.
POTENTIOMETER REPLACEMENT
The potentiometer has a life expectancy of fifty million revolutions.
As it becomes worn, the element may begin to produce noisy
signals or become non-linear. When signal noise or non-linearity
becomes unacceptable, replace the potentiometer. Refer to ex-
ploded view drawing and proceed as follows:
1.REMOVEMAINHOUSING
a) Unscrew nose cone from main housing. Set o-ring aside for
later use.
b) Gently push main housing latch.
c) While pushing latch, lift main housing up and remove it from
vertical shaft bearing rotor.