Observator OMC-160-3 User manual

OMC-160-3
OMC-160-3 Anemometer
Manual
Version 3.2 - November 2017
Author: Observator Instruments

OMC-160-3 Manual Page 2
Revisions:
2.04 (November 2013) previous versions OMC-160-2
3.0 (May 2017) OMC-160-3 introduction
3.1 (August 2017) OMC-160-3 reviewed manual
3.2 (November 2017) Update specifictions

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Index
1Introduction ........................................................................................................................................... 5
2Safety.................................................................................................................................................... 6
3Description............................................................................................................................................ 7
3.1 General description..................................................................................................................... 7
3.2 Main parts................................................................................................................................... 7
3.3 Moving parts ............................................................................................................................... 7
3.4 Theory of Operation.................................................................................................................... 7
3.5 Conditions of use........................................................................................................................ 7
3.6 Field use examples..................................................................................................................... 8
4Installation............................................................................................................................................. 8
4.1 Unpacking................................................................................................................................... 8
4.2 Location of the sensor ................................................................................................................ 8
4.3 Site preparation .......................................................................................................................... 9
4.4 Mounting / mechanical installation.............................................................................................. 9
4.5 Assembly of cup and vane.......................................................................................................... 9
4.6 Electrical installation ................................................................................................................. 11
4.6.1 Connections.......................................................................................................................... 11
4.6.2 Alignment LED’s ................................................................................................................... 12
4.6.3 Status LED’s......................................................................................................................... 12
5Commissioning ................................................................................................................................... 13
5.1 Commissioning procedure........................................................................................................ 13
5.1.1 Alignment of the wind vane.................................................................................................. 13
6Maintenance ....................................................................................................................................... 15
6.1 Maintenance schedule (preventive maintenance).................................................................... 15
6.2 Removing the OMC-160 anemometer from its location ........................................................... 15
6.3 Recalibration............................................................................................................................. 15
6.4 Opening and closing the anemometer...................................................................................... 16
6.5 Replacement of ball bearings and sensor PCB’s ..................................................................... 16
7Data protocol....................................................................................................................................... 19
7.1 General..................................................................................................................................... 19
7.2 Baudrate ................................................................................................................................... 19
7.3 Messages.................................................................................................................................. 19
8Specifications...................................................................................................................................... 20
8.1 Specifications............................................................................................................................ 20
9Support, service and warranty............................................................................................................ 21
10 Handling, transportation and storage.............................................................................................. 22
10.1 Handling.................................................................................................................................... 22
10.2 Long term storage..................................................................................................................... 22
10.3 Reshipping the instrument........................................................................................................ 22
11 Advanced configuration................................................................................................................... 23
12 Dimensional Drawing ...................................................................................................................... 24
13 EU Declaration of Conformity.......................................................................................................... 25

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1 Introduction
The Observator OMC-160-3 is the 3rd generation of this popular anemometer.
The sensor is often mounted in harsh conditions of the marine and offshore environment and it has
proven to be robust and reliable over the years. The OMC-160-3 continues the robust build quality
improved with the latest technology, which will make it even more reliable and easier to commission.
This manual is intended for the engineer doing the installation and commissioning and can also be used
as reference for the operator.

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2 Safety
For correct functioning the Observator OMC-160 Anemometer
must be installed and commissioned according installation &
commissioning instructions by a qualified engineer.
The Observator OMC-160 Anemometer has moving parts, which
can rotate fast during strong winds.
Keep clear of the cup and vane during strong winds!
The Observator OMC-160 Anemometer is usually installed at
height.
Technicians maintaining the system need to be qualified to work
at those heights whenever applicable!
Remember: instruments are tools.
They do NOT replace your own observations!
After end of life dispose this product according local regulations
or return to manufacturer.

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3 Description
3.1 General description
The Observator OMC-160-3 is a combined wind speed and direction meter using high accurate non-
contact sensors. It uses a rotary cup with 3 cups for speed and a stainless steel balanced vane for
direction measurement. It has a NMEA output signal and be combined with all Observator display and
MeteoLlink systems.
3.2 Main parts
The OMC-160 anemometer consists of a sensor body and a mounting bracket. Note that the mounting
bracket, though it was sometimes referred to as OMC-167, is an integral part of the OMC-160
anemometer. The mounting bracket has a mast clamp for mechanical connection and a junction box for
electrical connection. This clamp is designed for mounting on a vertical pipe end.
3.3 Moving parts
The only moving parts are the cup unit and the vane unit. The vane unit is mounted on top of the sensor
body, and the cup unit is mounted at the bottom of the sensor body. Both the cup unit and the vane unit
are wind driven. The wind speed sensor is a rotary cup type unit manufactured in stainless steel and
polycarbonate. The three cups are cone shaped for optimum response to varying winds. The vane unit is
made in stainless steel.
3.4 Theory of Operation
The OMC-160 is a cup and vane anemometer. Cup and vane anemometers are the most common
instrumentation for measurement of wind speed and direction. Cup and vane anemometers are the
primary sensors for wind measurement used by the leading meteorological services all over the world.
Therefore the readings of the OMC-160 anemometer are inter-comparable with the readings of other cup
and vane anemometers without any conversions.
For a more comprehensive discussion on the measurement principle please refer to Chapter 5 of the
WMO CIMO guide
1
3.5 Conditions of use.
The OMC-160 anemometer is built to provide reliable measurement results under all weather conditions.
Rain, snow, or other kinds of precipitation do not affect the readings. Further, the OMC-160 anemometer
is insensitive to noise, extreme temperatures, solar radiation, etc.
1
Guide to Meteorological Instruments and Methods of Observation, WMO No. 8, 7th Edition, World Meteorological
Organisation, Geneva, Switzerland, ISBN 92-63-16008-2

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3.6 Field use examples
4 Installation
4.1 Unpacking
The scope of supply of the OMC-160 anemometer consists of a Styrofoam and cardboard box
containing:
sensor body with integral mounting arm
cup unit
vane unit
U-bolts
mounting materials
this manual (on CD)
Note that additional materials that were simultaneously ordered for the same order might be packed in
the OMC-160 box.
4.2 Location of the sensor
Ensure that the OMC-160 anemometer will be mounted on a location where the wind that is free from
turbulence e.g. caused by obstacles nearby. Plan the OMC-160 anemometer in a free area as far as

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practicable. For guidance on the best location refer to the WMO CIMO Guide
2
. The location must be
accessible for yearly maintenance.
4.3 Site preparation
The OMC-160 anemometer bracket can be mounted on a vertical pipe end with an external diameter
between 35-60 mm. The pipe end should stop within 30 mm above the mounting clamp. In the vertical
plane there will be about 75 mm free space between the end of the pipe and the cup unit.
Make sure that the mast is properly fixed to withstand rugged wind forces. For calculation purposes: the
wind-capturing surface of the OMC-160 anemometer is approx. 700 cm2(0.07 m2 ). The pipe end must
be free of vibration.
The following tools are required for mechanical installation of the OMC-160 anemometer:
wrench 10 mm for M6 capped nuts
wrench 16 mm for M10 nuts on U-bolts
compass and/or binocular telescope
4.4 Mounting / mechanical installation
First connect the mounting clamp to the mast / pipe end. The top of the mounting clamp must be
mounted less than 30 mm under the end of the pipe to prevent the pipe end blocking the wind flow to the
cup unit.
Securely tighten the nuts on the U-bolts, preventing the nuts vibrate loose.
4.5 Assembly of cup and vane
The wind-sensors are shipped with the wind vane and cups disconnected from their appropriate units. On
the common unit, the upper spindle is for the wind direction sensor, and the lower spindle for the wind
speed sensor. To prevent damaging the wind vane and cups, properly mount the sensor/bracket
combination on the mast before fitting the wind vane and cup-unit whenever possible.
The shafts of the OMC-160 anemometer and the inside of the cup unit and vane unit are conical. This
enables fastening of the capped nut without the shaft turning along.
The cup unit and the vane blade are made of light materials for optimum response to the wind. Both are
balanced to provide accurate measurement and to prevent vibration. Take care not to damage the cup
unit or the vane blade while mounting.
Place the vane unit and mounting materials on the upper shaft in the following sequence:
1) Vane unit
2) Plain washer
3) Capped nut
Place the cup unit and mounting materials on the lower shaft in the following sequence:
1) Cup unit
2) Spring washer
3) Capped nut
2
Guide to Meteorological Instruments and Methods of Observation, WMO No. 8, 6th Edition, World Meteorological
Organisation, Geneva, Switzerland, ISBN 978-92-63-10008-5

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4.6 Electrical installation
4.6.1 Connections
The OMC-160 anemometer is provided with a junction box to connect the sensor to the field cabling.
The junction box provides a M20 gland for the power & signal cable.
If the OMC-160-3 heating option is fitted, an additional M20 gland is provided for a separate cable for
24 V heater power supply.
Table 1: Connector X1
Recommended cable: shielded 2x2x0.75mm2 (like OMC-494)
Terminal 5 must be used for NMEA shield connection.
Terminal 8 is meant as 0 reference in case the receiver has a RS422 input, a separate wire should be
used and connected to the signal ground of the receiver.
Do not use terminal 8 for shield connection, this can cause an earth fault!
Terminal
Function
Remarks
1
Power GND
2
Power +
3
NMEA output A / RS422 -
4
NMEA output B / RS422 +
5
Ground (connected to housing)
Shield connection NMEA out
6
Heater power, 24V (AC or DC)
Optional
7
Heater power, 24V (AC or DC)
Optional
8
RS422 0
Use only for RS422

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4.6.2 Alignment LED’s
Table 2: Upper LED’s on juntionbox PCB
On
+
Direction within 1 –5 degrees
N
Direction is 0 degrees
-
Direction within 355 - 359 degrees
4.6.3 Status LED’s
Table 3: Lower LED’s on juntionbox PCB
On
Off
S
Speed sensor OK
Speed sensor fault
D
Direction Sensor OK
Direction sensor fault
O
Flashes at NMEA output rate
No NMEA output

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5 Commissioning
5.1 Commissioning procedure
1) Check the connections.
2) Install the interface and (if applicable) the display instrument. Normally the OMC-160 anemometer is
powered through the interface unit.
3) Align the wind vane.
5.1.1 Alignment of the wind vane
The wind direction sensor needs to be aligned:
- To North; usually for land based or fixed applications.
- To the bow; usually for shipborne installations.
Procedure:
- Sensor needs to be powered
- Vane needs to be tightened
- Open the junction box.
- Direct the vane exactly to North or the bow; whichever is applicable.
- Press the alignment button, after approx. 3s until the alignment LED’s start flashing,
release the button.
- Check alignment: when correct, the middle LED (N) should lit. Repeat procedure if a
correction is required.
- Close the junction box and tighten carefully.
Note that the accuracy of the wind direction reading of the OMC-160 anemometer depends fully on
the alignment of the vane!
It is impossible to calibrate the OMC-160 anemometer in the field. However, the following procedure
makes sure that the installation was successful.
4) Check the direction readings. A various wind directions, make sure that the change in reading
corresponds to the direction of the vane. For interpretation of the wind direction reading, remind that
the wind direction is defined as the direction where the wind comes from. The readings should be
reasonable.
5) Check the wind speed reading. Table 4 can be used for estimation of the actual wind speed. The
reading should be reasonable.

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Table 4 Beaufort scale
Force
[Bft]
Speed
Name
Conditions at sea
Conditions on land
knots
m/s
0
< 1
<0.2
Calm
Sea like a mirror.
Smoke rises vertically.
1
1-3
0.3-1.5
Light air
Ripples only.
Smoke drifts and leaves rustle.
2
4-6
1.6-3.3
Light breeze
Small wavelets (0.2 m). Crests
have a glassy appearance.
Wind felt on face.
3
7-10
3.4-5.5
Gentle breeze
Large wavelets (0.6 m), crests
begin to break.
Flags extended, leaves move.
4
11-16
5.5-7.9
Moderate
breeze
Small waves (1 m), some
whitecaps.
Dust and small branches move.
5
17-21
8.0-10.7
Fresh breeze
Moderate waves (1.8 m), many
whitecaps.
Small trees begin to sway.
6
22-27
10.8-13.8
Strong breeze
Large waves (3 m), probably
some spray.
Large branches move, wires
whistle, umbrellas are difficult to
control.
7
28-33
13.9-17.1
Near gale
Mounting sea (4 m) with foam
blown in streaks downwind.
Whole trees in motion,
inconvenience in walking.
8
34-40
17.2-20.7
Gale
Moderately high waves (5.5
m), crests break into spindrift.
Difficult to walk against wind.
Twigs and small branches blown
off trees.
9
41-47
20.8-24.4
Strong gale
High waves (7 m), dense foam,
visibility affected.
Minor structural damage may
occur (shingles blown off roofs).
10
48-55
24.5-28.4
Storm
Very high waves (9 m), heavy
sea roll, visibility impaired.
Surface generally white.
Trees uprooted, structural
damage likely.
11
56-63
28.5-32.6
Violent storm
Exceptionally high waves (11
m), visibility poor.
Widespread damage to
structures.
12
64+
>32.6
Hurricane
14 m waves, air filled with
foam and spray, visibility bad.
Severe structural damage to
buildings, wide spread
devastation.

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6 Maintenance
6.1 Maintenance schedule (preventive maintenance)
Initial maintenance interval is two year under normal circumstances. Maintenance is best planned in the
season when outside work is most comfortable.
For critical applications (where wind data is of major importance) under severe conditions, an initial
maintenance interval of 12 to even 6 months might be considered.
The maintenance interval can be adjusted depending on the maintenance experience.
Periodic maintenance comprises inspection on the following points:
check ball bearings; replace if necessary
check cabling and cable support
check mounting; retighten if necessary
clean the sensor if necessary
Refer to paragraph 6.5 for more information about the mechanical aspects. If the ball bearings require
replacement, the OMC-160 anemometer must be removed from its location.
6.2 Removing the OMC-160 anemometer from its location
1) Disconnect the power supply tot the sensor (display / data collection unit or PSU).
2) Remove the vane unit and the cup unit.
The cup unit and the vane blade are made of light materials for optimum response to the wind. Both are
balanced to provide accurate measurement and to prevent vibration.
Take care not to damage the cup unit or the vane blade while mounting or disassembly.
The shafts of the OMC-160 anemometer and the inner side of the cup unit and vane unit are conical.
After removal of the capped nut and washer, it might require a careful tap to loosen the cup unit or vane
unit from its shaft.
3) Disconnect the cable in the junction box.
4) Loose the U-bolts and remove the OMC-160 body from its location.
6.3 Recalibration
If the OMC-160 anemometer is included in a calibration program, the recommended calibration interval is
2 years. If required, you can adjust this interval.
Calibration of wind speed sensor is only possible in a wind tunnel. Observator Instruments B.V. provides
calibration services. For address details see chapter 9. Always include the cup unit and the vane unit
when the OMC-160 anemometer is shipped for recalibration.

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6.4 Opening and closing the anemometer
The Observator OMC-160 anemometer is designed for low maintenance. The construction is entirely
made of non-corrosive materials and all components are conservatively rated.
The only components that are likely to require replacement due to normal wear are the precision ball
bearings. The OMC-160 anemometer must be opened to replace the bearings.
The OMC-160 anemometer should only be opened or disassembled in a clean workshop
The OMC-160 anemometer should only be opened or disassembled by a qualified
mechanical engineer
Refer to the assembly drawings of the anemometer for part names and locations.
First remove the cup unit or vane unit from their body by unscrewing the capped nut and lifting the unit.
Unscrew the bearing housing (2) or (3)
6.5 Replacement of ball bearings and sensor PCB’s
First, open the sensor housing as described in section 0
To gain access to the bearings remove the bearing cover-plate. The bearings can now be taken out
complete with the shaft.
Direction head assembly Speed head assembly Shaft –bearing assembly
(identical* for both heads)
1. Shaft 8. Hex screw
2. Bearing cover end plate 9. Circlip large*
3. Bearing cover (speed) plate** 10. Bearing large
4. Columns 11. Bearing small
5. Sensor element 12. Circlip small
6. Sensor PCB / Connector 13. Connector Cable assembly
7. Hex bolts 14. Ground wire
* Circlip (9) only present when no bearing cover (4) is fitted
** Bearing cover plate is replaced by Circlip 9 in some speed heads and all direction heads.

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Sensor PCB (6) removal
Identical for both speed and direction head:
1. Take the cable connector (13) out of the PCB connector of the sensor PCB.
2. Remove the 3 hex bolts (7), this will also release the ground wire (14).
Bearing removal
Identical for both speed and direction head unless otherwise specified:
1. First remove PCB (see Sensor PCB (6) removal)
2. Remove the 3 columns (4)
3. Loosen the sensor element hex screw (8)
4. Remove the sensor element (5)
5. Remove the bearing cover plate (3) (Speed head only if applicable)
6. Remove the large circlip (9)
7. Loosen the 2 screws of the bearing cover end plate (2) and remove the plate
8. Carefully tap out the bearing assembly from the outside in using a suitable driver (dia
18mm+/-0.5) and hammer or press.
9. Remove small circlip
10. Use a pulley or press to remove bearings from shaft.

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When the bearings are renewed, care should be taken not to apply excessive force on the new bearings.
When re-installing the complete bearing housing with the sensor PCB’s, care should be taken that the
internal wiring is properly attached, and not touching any moving part.

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7 Data protocol
7.1 General
The output of the OMC-160-3 is NMEA-0183 according IEC 61162-1.
7.2 Baudrate
The default baudrate is 4800 baud, 9600 baud can be set via the setup menu.
7.3 Messages
The OMC-160-3 NMEA-0183 output has the following messages:
$WIMWV,x.x,R,x.x,M,A*hh<CR><LF>
1 2 3 4 5
1. Wind angle, 0 to 359 degrees
2. Reference:
R = Relative
T = Theoretical
Always R(elative) for OMC-160-3
3. Wind speed
4. Wind speed units: K/M/N/S (always M = Meter / second for OMC-160-3)
5. Status, A = Data Valid, V = Data invalid
$WIVER,1,1,WI,OBS,c--c,c--c,c--c,c--c,c--c,x*hh<CR><LF>
1 2 3 4 5 6 7 8 9 10
1. Total number of sentences needed, 1 to 9 (1)
2. Sentence number, 1 to 9 (1)
3. Device type (WI)
4. Vendor ID (OBS)
5. Unique Identifier (n/a, blank)
6. Manufacturer serial number (actual serial number of the unit)
7. Model code (OMC-160-3))
8. Software revision (actual firmware revision id of the unit)
9. Hardware revision (n/a, blank)
10. Sequential message identifier (0)
All parameters except 6 & 8 will be identical for each OMC-160-3 wind sensor.
Parameter 6 will be unique for each unit (Serial number)
Example Strings
$WIMWV,90.0,R,5.0,N,A*1F
$WIMWV,90.0,R,17.0,N,A*2C
$WIVER,1,1,WI,OBS,,160300008,OMC-160-3,00.08B00,,0*02

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8 Specifications
8.1 Specifications
Parameter
Value
Type of instrument
Anemometer
Measuring principle
Cup and vane
Measuring system
ISO –Metric
Materials of exposed parts
Stainless steel
Material of cups
Polycarbonate
Ingress Protection
IP-65 according to EN-60529
Operation Temperature
-25 … +70 deg. C
Humidity
5 … 90%
Measuring range (wind speed)
0 … 75 m/s
Accuracy (wind speed)
Better than 2 %
Threshold (speed)
Approx. 0.3 m/s
Distance constant
1.68 meters
Measuring range (wind direction)
0 … 360 º (no gap)
Direction accuracy (non-linearity etc.)
+/- 2 degrees
Output signal compatibility
NMEA 0183 v4.10 / IEC61162-1
Overall height
Approx. 905 mm
Overall width (vane mounted)
Approx. 460 mm max.
Mounting method
Pole-mounting bracket with U-bolts (M10) for
mounting on cylindrical or square pole
Clamping range
35 to 65 mm
Weight
Approx. 5 kgs. excluding cable
Packing dimensions
1050 x 510 x 150 mm
Packing weight
10 kgs.