Campbell 024A Instruction Manual
Model 024A Met One
Wind Direction Sensor
Revision: 6/10
Copyright © 1989-2010
Campbell Scientific, Inc.
Warranty and Assistance
The 024A MET-ONE WIND DIRECTION SENSOR is warranted by
Campbell Scientific, Inc. to be free from defects in materials and workmanship
under normal use and service for twelve (12) months from date of shipment
unless specified otherwise. Batteries have no warranty. Campbell Scientific,
Inc.'s obligation under this warranty is limited to repairing or replacing (at
Campbell Scientific, Inc.'s option) defective products. The customer shall
assume all costs of removing, reinstalling, and shipping defective products to
Campbell Scientific, Inc. Campbell Scientific, Inc. will return such products
by surface carrier prepaid. This warranty shall not apply to any Campbell
Scientific, Inc. products which have been subjected to modification, misuse,
neglect, accidents of nature, or shipping damage. This warranty is in lieu of all
other warranties, expressed or implied, including warranties of merchantability
or fitness for a particular purpose. Campbell Scientific, Inc. is not liable for
special, indirect, incidental, or consequential damages.
Products may not be returned without prior authorization. The following
contact information is for US and International customers residing in countries
served by Campbell Scientific, Inc. directly. Affiliate companies handle
repairs for customers within their territories. Please visit
www.campbellsci.com to determine which Campbell Scientific company
serves your country.
To obtain a Returned Materials Authorization (RMA), contact Campbell
Scientific, Inc., phone (435) 753-2342. After an applications engineer
determines the nature of the problem, an RMA number will be issued. Please
write this number clearly on the outside of the shipping container. Campbell
Scientific's shipping address is:
CAMPBELL SCIENTIFIC, INC.
RMA#_____
815 West 1800 North
Logan, Utah 84321-1784
For all returns, the customer must fill out a “Declaration of Hazardous Material
and Decontamination” form and comply with the requirements specified in it.
The form is available from our website at
completed form must be either emailed to repair@campbellsci.com
435-750-9579. Campbell Scientific will not process any returns until we
receive this form. If the form is not received within three days of product
receipt or is incomplete, the product will be returned to the customer at the
customer’s expense. Campbell Scientific reserves the right to refuse service on
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www.campbellsci.com/repair
. A
or faxed to
024A Table of Contents
PDF viewers note: These page numbers refer to the printed version of this document. Use
the Adobe Acrobat® bookmarks tab for links to specific sections.
1. Function........................................................................1
2. Specifications ..............................................................1
3. Installation....................................................................2
3.1 Siting.........................................................................................................2
3.2 Assembly and Mounting...........................................................................2
4. Wiring............................................................................3
5. Programming ...............................................................3
5.1 Datalogger Instruction..............................................................................3
5.2 Calibration and Orientation ......................................................................4
5.3 Example Programs....................................................................................5
6. General Maintenance Schedule..................................8
6.1 6 to 12 Month Periodic Service *.............................................................8
6.2 24 to 36 Month Service * .........................................................................8
7. References .................................................................11
Appendix
A. Wind Direction Sensor Orientation........................A-1
A.1 Determining True North and Sensor Orientation................................ A-1
Figures
3-1. Bushing Installation on 024A Sensor......................................................2
3-2. Schematic of 024A Wind Direction Sensor ............................................3
6-1. Cable Diagram.........................................................................................8
6-2. Parts Diagram..........................................................................................9
A-1. Magnetic Declination for the Contiguous United States................... A-2
A-2. Declination Angles East of True North Are Subtracted From 0
to Get True North ........................................................................ A-2
A-3. Declination Angles West of True North Are Added to 0
to Get True North ........................................................................ A-3
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024A Table of Contents
Tables
1-1. Recommended Lead Lengths ................................................................. 1
4-1. Connections to Campbell Scientific Dataloggers................................... 3
5-1. Parameters for Wind Direction............................................................... 4
6-1. Met-One Parts List Reproduced by Campbell Scientific, Inc............... 10
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024A Met-One Wind Direction Sensor
1. Function
The Met-One 024A Wind Vane measures wind direction from 0 to 360 degrees
with a 5 degree accuracy specification. The 024A utilizes a potentiometer to
vary the sensor resistance in relation to wind direction.
Lead length for the 024A is specified when the sensor is ordered. Table 1-1
gives the recommended lead length for mounting the sensor at the top of a
tripod/tower via a CM202 or 019ALU crossarm.
TABLE 1-1. Recommended Lead Lengths
CM6 CM10 CM110 CM115 CM120 UT10 UT20 UT30
11’ 14’ 14’ 19’ 24’ 14’ 24’ 37’
2. Specifications
Range 0 to 360 degrees
Threshold 0.447 m/s (1.0 mph)
Accuracy ±5 degrees
Temperature Range -50°C to +70°C
Delay Distance Less than 1.5 m (5 ft.)
Damping Ratio
Standard 0.25
Optional 0.4
Potentiometer Specifications
Sand, Dust, and Fungus MIL-E-5272
Salt Spray MIL-E-12934
Resistance 0-10,000 Ohms
Weight 450 g (1 lb.)
Dimensions
Overall height 13.3” (33.8 cm)
Overall length 17.6” (44.7 cm)
Tail height 12” (30.5 cm)
Tail Width 3” (7.6 cm)
1
024A Met-One Wind Direction Sensor
3. Installation
3.1 Siting
Locate wind sensors away from obstructions (e.g. trees and building). As a
general rule of thumb there should be a horizontal distance of at least ten times
the height of the obstruction between the windset and the obstruction. If it is
necessary to mount the sensors on the roof of a building, the height of the
sensors, above the roof, should be at least 1.5 times the height of the building.
See Section 7 for a list of references that discuss siting wind direction sensors.
3.2 Assembly and Mounting
Remove the Allen hex screw in the lower part of the sensor housing and insert
the 024A in the mounting bushing (see Figure 3-1). Tighten the screw in the
bushing onto the sensor housing.
Mount the crossarm to the tripod or tower. Orient the crossarm North-South,
with the CM220 mount or 17953 1” x 1” NU-RAIL fitting on the North end.
Insert the sensor in the CM220 or NU-RAIL fitting. Align the sensor so that
the counter weight points to true South and tighten the u-bolts on the CM220
or tighten the set screws on the NU-RAIL fitting.
NOTE
Appendix A contains detailed information on determining and
using a compass and the magnetic declination for the site.
Connect the cable assembly to the sensor receptacle.
2
FIGURE 3-1. Bushing Installation on 024A Sensor
4. Wiring
024A Met-One Wind Direction Sensor
FIGURE 4-1. Schematic of 024A Wind Direction Sensor
Figure 4-1, Figure 6-1, and Table 4-1 shows wiring. When Short Cut for
Windows software is used to create the datalogger program, the sensor should
be wired to the channels shown on the wiring diagram created by Short Cut.
Color
Description
Red Wind Dir. Signal SE Analog SE Analog SE Analog SE Analog
Black Wind Dir. Excitation Excitation Excitation Excitation Excitation
White Wind Dir. Reference
Clear Wind Dir. Shield
5. Programming
NOTE
5.1 Datalogger Instruction
TABLE 4-1. Connections to Campbell Scientific Dataloggers
CR800
CR5000
CR3000
CR1000
CR510
CR500
CR10(X)
AG
G
21X
CR7
CR23X
This section is for users who write their own programs. A
datalogger program to measure this sensor can be created using
Campbell Scientifics’ Short Cut Program Builder software. You
do not need to read this section to use Short Cut.
CR200(X)
The datalogger instruction that measures the 024A is datalogger dependent.
The BRHalf measurement instruction is used for our CR800, CR850, CR1000,
CR3000, and CR5000 dataloggers. Our CR200(X)-series dataloggers use the
EX-DEL_SE. Our Edlog dataloggers (e.g., CR510, CR10(X), CR23X) use
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