INSTRUCTION MANUAL
CSAT3 Three Dimensional
Copyright © 1998- 2014
Campbell Scientific, Inc.
Sonic Anemometer
Revision: 9/14
Limited Warranty
“Products manufactured by CSI are warranted by CSI to be free from defects in
materials and workmanship under normal use and service for twelve months
from the date of shipment unless otherwise specified in the corresponding
product manual. (Product manuals are available for review online at
www.campbellsci.com.) Products not manufactured by CSI, but that are resold
by CSI, are warranted only to the limits extended by the original manufacturer.
Batteries, fine-wire thermocouples, desiccant, and other consumables have no
warranty. CSI’s obligation under this warranty is limited to repairing or
replacing (at CSI’s option) defective Products, which shall be the sole and
exclusive remedy under this warranty. The Customer assumes all costs of
removing, reinstalling, and shipping defective Products to CSI. CSI will return
such Products by surface carrier prepaid within the continental United States of
America. To all other locations, CSI will return such Products best way CIP
(port of entry) per Incoterms ® 2010. This warranty shall not apply to any
Products which have been subjected to modification, misuse, neglect, improper
service, accidents of nature, or shipping damage. This warranty is in lieu of all
other warranties, expressed or implied. The warranty for installation services
performed by CSI such as programming to customer specifications, electrical
connections to Products manufactured by CSI, and Product specific training, is
part of CSI’s product warranty. CSI EXPRESSLY DISCLAIMS AND
EXCLUDES ANY IMPLIED WARRANTIES OF MERCHANTABILITY
OR FITNESS FOR A PARTICULAR PURPOSE. CSI hereby disclaims,
to the fullest extent allowed by applicable law, any and all warranties and
conditions with respect to the Products, whether express, implied or
statutory, other than those expressly provided herein.”
Assistance
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) 227-9000. After an application 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 “Statement of Product Cleanliness
and Decontamination” form and comply with the requirements specified in it.
The form is available from our web site at www.campbellsci.com/repair. A
completed form must be either emailed to repair@campbellsci.com or faxed to
(435) 227-9106. Campbell Scientific is unable to 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
products that were exposed to contaminants that may cause health or safety
concerns for our employees.
Precautions
DANGER — MANY HAZARDS ARE ASSOCIATED WITH INSTALLING, USING, MAINTAINING, AND WORKING ON OR AROUND
TRIPODS, TOWERS, AND ANY ATTACHMENTS TO TRIPODS AND TOWERS SUCH AS SENSORS, CROSSARMS, ENCLOSURES,
ANTENNAS, ETC. FAILURE TO PROPERLY AND COMPLETELY ASSEMBLE, INSTALL, OPERATE, USE, AND MAINTAIN TRIPODS,
TOWERS, AND ATTACHMENTS, AND FAILURE TO HEED WARNINGS, INCREASES THE RISK OF DEATH, ACCIDENT, SERIOUS
INJURY, PROPERTY DAMAGE, AND PRODUCT FAILURE. TAKE ALL REASONABLE PRECAUTIONS TO AVOID THESE HAZARDS.
CHECK WITH YOUR ORGANIZATION’S SAFETY COORDINATOR (OR POLICY) FOR PROCEDURES AND REQUIRED PROTECTIVE
EQUIPMENT PRIOR TO PERFORMING ANY WORK.
Use tripods, towers, and attachments to tripods and towers only for purposes for which they are designed. Do not exceed design
limits. Be familiar and comply with all instructions provided in product manuals. Manuals are available at www.campbellsci.com or
by telephoning (435) 227-9000 (USA). You are responsible for conformance with governing codes and regulations, including safety
regulations, and the integrity and location of structures or land to which towers, tripods, and any attachments are attached. Installation
sites should be evaluated and approved by a qualified engineer. If questions or concerns arise regarding installation, use, or
maintenance of tripods, towers, attachments, or electrical connections, consult with a licensed and qualified engineer or electrician.
General
• Prior to performing site or installation work, obtain required approvals and permits. Comply
with all governing structure-height regulations, such as those of the FAA in the USA.
• Use only qualified personnel for installation, use, and maintenance of tripods and towers, and
any attachments to tripods and towers. The use of licensed and qualified contractors is
highly recommended.
• Read all applicable instructions carefully and understand procedures thoroughly before
beginning work.
• Wear a hardhat and eye protection, and take other appropriate safety precautions while
working on or around tripods and towers.
• Do not climb tripods or towers at any time, and prohibit climbing by other persons. Take
reasonable precautions to secure tripod and tower sites from trespassers.
• Use only manufacturer recommended parts, materials, and tools.
Utility and Electrical
• You can be killed or sustain serious bodily injury if the tripod, tower, or attachments you are
installing, constructing, using, or maintaining, or a tool, stake, or anchor, come in contact
with overhead or underground utility lines.
• Maintain a distance of at least one-and-one-half times structure height, 20 feet, or the
distance required by applicable law, whichever is greater, between overhead utility lines and
the structure (tripod, tower, attachments, or tools).
• Prior to performing site or installation work, inform all utility companies and have all
underground utilities marked.
• Comply with all electrical codes. Electrical equipment and related grounding devices should
be installed by a licensed and qualified electrician.
Elevated Work and Weather
• Exercise extreme caution when performing elevated work.
• Use appropriate equipment and safety practices.
• During installation and maintenance, keep tower and tripod sites clear of un-trained or non-
essential personnel. Take precautions to prevent elevated tools and objects from dropping.
• Do not perform any work in inclement weather, including wind, rain, snow, lightning, etc.
Maintenance
• Periodically (at least yearly) check for wear and damage, including corrosion, stress cracks,
frayed cables, loose cable clamps, cable tightness, etc. and take necessary corrective actions.
• Periodically (at least yearly) check electrical ground connections.
WHILE EVERY ATTEMPT IS MADE TO EMBODY THE HIGHEST DEGREE OF SAFETY IN ALL CAMPBELL SCIENTIFIC PRODUCTS,
THE CUSTOMER ASSUMES ALL RISK FROM ANY INJURY RESULTING FROM IMPROPER INSTALLATION, USE, OR
MAINTENANCE OF TRIPODS, TOWERS, OR ATTACHMENTS TO TRIPODS AND TOWERS SUCH AS SENSORS, CROSSARMS,
ENCLOSURES, ANTENNAS, ETC.
Table of Contents
PDF viewers: These page numbers refer to the printed version of this document. Use the
PDF reader bookmarks tab for links to specific sections.
1. General ........................................................................ 1
2. Specifications ............................................................. 1
2.1 Measurements ...................................................................................... 1
2.2 Output Signals ...................................................................................... 2
2.3 Physical Description ............................................................................ 3
2.4 Power Requirements ............................................................................ 4
3. Initial Setup ................................................................. 4
3.1 Factory Settings ................................................................................... 4
3.2 SDM Address ....................................................................................... 5
4. Installation ................................................................... 5
4.1 Orientation ........................................................................................... 5
4.2 Mounting .............................................................................................. 6
4.3 Leveling ............................................................................................... 8
4.4 Fine Wire Thermocouple ..................................................................... 8
5. Wiring ........................................................................... 8
6. CSAT3 Outputs ......................................................... 11
6.1 SDM Output ....................................................................................... 11
6.1.1 CRBasic Dataloggers .................................................................. 12
6.1.2 EDLOG Dataloggers ................................................................... 12
6.1.3 CR9000 ....................................................................................... 12
6.2 RS-232 Output ................................................................................... 13
6.3 Analog Output .................................................................................... 13
7. Operational Principles .............................................. 13
7.1 Embedded Code Version 4 ................................................................ 13
7.2 Embedded Code Version 3 ................................................................ 14
7.3 Effects of Crosswind on the Speed of Sound ..................................... 15
8. CSAT3 Trigger ........................................................... 16
8.1 Sampling Modes ................................................................................ 17
8.1.1 Single-Measurement Mode ......................................................... 18
8.1.2 Oversample Mode ....................................................................... 18
9. Data Pipeline Delay ................................................... 18
10. Datalogger Programming using SDM ..................... 19
i
Table of Contents
10.1 CRBasic CSAT3 () Instruction .......................................................... 19
10.2 EDLOG SDM-CSAT3 (P107) Instruction ........................................ 19
10.3 Datalogger Instruction Parameters .................................................... 19
10.4 Diagnostic Word ............................................................................... 22
10.5 SDMTrigger ()/SDM-Group Trigger (P110) ..................................... 23
10.6 Example CRBasic Datalogger Program ............................................ 23
10.7 Example EDLOG Datalogger Program ............................................. 28
11. Maintenance .............................................................. 37
11.1 Wicks................................................................................................. 38
11.2 Calibration ......................................................................................... 39
11.2.1 Cold Shifted Calibration ............................................................ 39
11.2.2 Test for Wind Offset .................................................................. 40
12. Select Backdoor Commands ................................... 42
Appendices
CSAT3 Orientation .................................................. A-1
A.
A.1 Determining True North and Sensor Orientation ............................ A-1
A.2 Online Magnetic Declination Calculator ......................................... A-3
B. Serial Communications with the CSAT3 ............... B-1
B.1 CSAT3 RS-232 Commands ............................................................ B-1
B.2 CSAT3 Binary Data Output Format ................................................ B-3
B.3 Words 0 through 3 ........................................................................... B-4
B.4 Word 4 ............................................................................................. B-5
B.5 CSAT3 RS-232 Status Format ........................................................ B-5
C. CSAT3 Measurement Theory ................................. C-1
C.1 Theory of Operation ........................................................................ C-1
C.1.1 Wind Speed .............................................................................. C-1
C.1.2 Temperature ............................................................................. C-1
D. SDM Communications and Long Signal Cables .. D-1
D.1 Brief Description of SDM Clock Rates ........................................... D-1
D.2 CR3000 Example ............................................................................ D-2
D.3 CR23X Example ............................................................................. D-2
Figures
4-1. CSAT3 coordinate system and current captive mounting hardware
(s/n 0631 to current) ......................................................................... 6
4-2. CSAT3 coordinate system and captive mounting hardware (s/n
0631 to current) ................................................................................ 7
4-3. CSAT3 coordinate system, captive mounting hardware, and cup
washer (s/n 0107 to 0630) ................................................................ 7
4-4. CSAT3 coordinate system and original noncaptive mounting
hardware (s/n 0107 to 0630) ............................................................ 8
8-1. Typical average CSAT3 current drain at +12 VDC .......................... 17
ii
Tables
Table of Contents
8-2. CSAT3 pipeline delay ........................................................................ 17
11-1. Proper location of the top (pn 17388) and bottom (pn 17389)
wicks ............................................................................................... 38
11-2. P/N 28902 CSAT3 Sonic Wick Spares Kit contents .......................... 39
11-3. CSAT3 running at 1 Hz and successfully communicating with the
CSAT3 ............................................................................................ 40
11-4. Recommended settings for the wind vertical axis .............................. 41
11-5. Recommended settings for the wind vertical axis labels .................... 41
11-6. Wind data from CSAT3 s/n 315; wind offsets within
specifications at 19 °C .................................................................... 42
A-1. Magnetic declination for the conterminous United States (2004) ... A-1
A-2. A declination angle East of True North (positive) is subtracted
from 360 (0) degrees to find True North ..................................... A-2
A-3. A declination angle West of True North (negative) is subtracted
from 0 (360) degrees to find True North ..................................... A-2
A-4. USGS web calculator ...................................................................... A-3
B-1. PC as the trigger source ................................................................... B-3
B-2. CSAT3 as the trigger source ............................................................ B-3
3-1. SDM Addressing Scheme .................................................................... 5
5-1. CSAT3 Power ...................................................................................... 9
5-2. CSAT3 SDM Output to a CR3000, CR5000, and CR9000X
Datalogger ........................................................................................ 9
5-3. CSAT3 SDM Output to a CR1000, CR800/850, CR23X and
CR10(X) Datalogger ......................................................................... 9
5-4. CSAT3 SDM Output to a 21X Datalogger ........................................ 10
5-5. CSAT3 SDM Output to a CR9000 Datalogger .................................. 10
5-6. CSAT3 RS-232 Output Pin Out ......................................................... 10
5-7. CSAT3 Analog Output Wiring .......................................................... 10
5-8. FW05/FWC-L35 Fine Wire Thermocouple ....................................... 11
6-1. CSAT3 Outputs .................................................................................. 11
6-2. SDM Compatible Dataloggers ........................................................... 12
6-3. Calibration for Analog Outputs .......................................................... 13
10-1. CSAT3 () Instruction Parameters ....................................................... 19
10-2. SDM-CSAT3 (P107) Instruction Parameters ..................................... 19
10-3. CR3000, CR1000, CR5000, CR800/850, CR9000(X), CR23X
and 21X Execution Interval and CSAT3 Execution Parameter ...... 21
10-4. CR10(X) Execution Interval and CSAT3 Execution Parameter ........ 21
10-5. Diagnostic Word ................................................................................ 22
10-6. CSAT3 Diagnostic Flags ................................................................... 23
10-7. Wiring for Program Example 1 .......................................................... 24
10-8. Wiring for Program Example 2 .......................................................... 29
B-1. RS-232 Command Codes ................................................................. B-2
B-2. RS-232 Output ................................................................................. B-4
B-3. Converting ux Wind from Word 0 .................................................... B-4
B-4. Converting uy Wind from Word 1 .................................................... B-4
B-5. Converting uz Wind from Word 2 .................................................... B-4
B-6. Converting Speed of Sound from Word 3 ........................................ B-5
B-7. Decoding the Diagnostic Flags from Word 4 ................................... B-5
B-8. Special Case – Not a Number .......................................................... B-5
B-9. RS-232 Status, Response to the S or P Command ........................... B-6
D-1. Data from Example CR3000 SDM Clock Rate Search Program .... D-2
D-2. Data from Example CR23X SDM Clock Rate Search Program ..... D-3
D-3. SDM Clock Rate Report ................................................................. D-3
iii
Table of Contents
iv
CSAT3 Three Dimensional Sonic
Anemometer
1. General
The CSAT3 is an ultrasonic anemometer for measuring wind speed in three
dimensions. It uses three pairs of non-orthogonally oriented transducers to
sense the horizontal wind. Each pair of transducers transmits and receives the
ultrasonic signal. The time of flight is directly related to the wind speed along
the sonic transducer axis. The speed of sound is directly related of the air
density, e.g. temperature and humidity.
The CSAT3 can be used to measure average horizontal wind speed and
direction or turbulent fluctuations of horizontal and vertical wind. From the
turbulent wind fluctuations, momentum flux is calculated. By finding the
covariance between vertical wind and scalars, sensible, latent heat, carbon
dioxide flux is directly be measured.
The sonic transducers are sealed and will not be damaged should they become
wet. The CSAT3 will continue to make wind measurements under rainy
conditions; however, like all ultrasonic anemometers, should the transducers be
sufficiently obscured, the CSAT3 will be unable to make further
measurements.
The CSAT3 can be measured using SDM (Synchronous Device for
Measurements) communications and a Campbell Scientific, Inc. datalogger.
All Campbell Scientific dataloggers that support the CSAT3 SDM instruction
do so without a special operating system with the exception of the 21X and
CR10, see TABLE 6-2 for compatible dataloggers.
The fine wire thermocouple used with the CSAT3 is the FW05. It is a 0.0005inch diameter thermocouple mounted on a stainless steel bayonet. A FWC-L35
cable is required with the FW05. Four feet of the FWC-L35 is bundled inside
the enclosure to minimize conduction of heat into the terminal strips. The
remaining 31 feet permits mounting the FW05 to the side of the CSAT3 head.
Finally, the thermocouple cover (pn 10080) is placed over the connectors. This
cover is used to mount the connectors to the side of the CSAT3 head and
minimize the temperature gradient across the omega brand connectors.
2. Specifications
2.1 Measurements
The CSAT3 measures wind speed and the speed of sound along the three nonorthogonal sonic axes. The wind speeds are then transformed into the
orthogonal wind components u
anemometer head; the reported speed of sound (c) or sonic virtual temperature
), is the average between the three non-orthogonal sonic axes. The errors
(T
s
caused by wind blowing normal to the sonic path are corrected online before
the wind speed is transformed into orthogonal coordinates. It is not necessary
to apply the speed of sound correction described by Liu et al., 2001. The
, uy, and uz and are referenced to the
x
1
CSAT3 Three Dimensional Sonic Anemometer
CSAT3 can be configured to make a single measurement per trigger or
multiple measurements that are centered around the trigger (oversampled).
OUTPUTS: u
, uy, uz, and c (ux, uy, uz, are orthogonal wind components
x
referenced to the anemometer head; c is the speed of sound)
SPEED OF SOUND: determined from 3 acoustic paths; corrected for
crosswind effects
MEASUREMENT RATE: programmable from 1 to 60 Hz, instantaneous
measurements; two oversampled modes are block averaged to either 20 Hz or
10 Hz
MEASUREMENT RESOLUTION: u
0.5 mm s
(standard) [c is 1 mm s
–1
rms; c is 15 mm s–1 (0.025 °C) with embedded code version 4
–1
(0.002 °C) with embedded code version 3]; wind
and uy are 1 mm s–1 rms; uz is
x
direction is 0.06 degrees rms. Values are the standard deviations of
instantaneous measurements made of a constant signal. The noise is unaffected
by the sample rate.
OPERATING TEMPERATURE RANGE: –30 to 50 °C (standard); –40 to
40 °C (cold shifted)
ACCURACY (–30 to 50 °C and –40 to 40 °C operating range; wind speed
< 30 m s
–1
; azimuth angles between ±170°):
Offset Error:
u
u
, uy: < ±8 cm s–1
x
: < ±4 cm s–1
z
Gain Error:
Wind vector within ±5° of horizontal < ±2 percent of reading
Wind vector within ±10° of horizontal < ±3 percent of reading
Wind vector within ±20° of horizontal < ±6 percent of reading
Wind Direction Accuracy:
±0.7° at 1 m s
2.2 Output Signals
The CSAT3 can output data to a data retrieval system using any of the
following communications: SDM (Synchronous Device for Measurement),
RS-232, or analog output. All the output signals have a two scan delay.
DIGITAL SDM: A Campbell Scientific, Inc. 33300 bps serial interface for
datalogger/sensor communication
Data type: 2-byte integer per output plus 2-byte diagnostic and 2-byte
configuration parameter
DIGITAL RS-232: Baud rate: 9600 bps or 19200 bps
Data type: 2-byte integer per output plus 2-byte diagnostic
ANALOG: Number of outputs: 4
Voltage range: ±5 V
Number of bits: 12
–1
for horizontal wind
2
REPORTING RANGE:
SDM and RS-232 digital Outputs:
Full scale wind: ±65.535 m s
significant bit is 0.25 to 2 mm s
Speed of sound: 300 to 366 m s
1 mm s
–1
(0.025 °C embedded code version 4; 0.002 °C embedded code
version 3)
ANALOG OUTPUTS:
Output Range LSB
ux, uy ±32.768 m s–1 15 mm s–1
±65.536 m s
u
±8.192 m s–1 4 mm s–1
z
c 300 to 366 m s
2.3 Physical Description
MEASUREMENT PATH LENGTH: 10.0 cm vertical; 5.8 cm horizontal
TRANSDUCER PATH ANGLE FROM HORIZONTAL: 60 degrees
CSAT3 Three Dimensional Sonic Anemometer
–1
autoranging between four ranges; least
–1
–1
(–50 to +60 °C); least significant bit is
–1
30 mm s–1
–1
16 mm s
–1
(–50 to +60 °C) (0.026 °C)
TRANSDUCER: 0.64 cm (0.25 in) diameter
TRANSDUCER MOUNTING ARMS: 0.84 cm (0.33 in) diameter
SUPPORT ARMS: 1.59 cm (0.63 in) diameter
DIMENSIONS:
Anemometer Head: 47.3 cm (l) x 42.4 cm (h) (18.6 in x 16.7 in)
Electronics Box: 26 cm x 16 cm x 9 cm (10.2 in x 6.3 in x 3.5 in)
Carrying Case: 71.1 cm x 58.4 cm x 33 cm (28 in x 23 in 13 in)
WEIGHT:
Anemometer Head: 1.7 kg (3.7 lb)
Electronics Box: 2.8 kg (6.1 lb)
Shipping: 16.8 kg (37 lb)
3
CSAT3 Three Dimensional Sonic Anemometer
2.4 Power Requirements
3. Initial Setup
3.1 Factory Settings
VOLTAGE SUPPLY: 10 to 16 Vdc
POWER:
2.4 W @ 60 Hz measurement frequency
1.2 W @ 20 Hz measurement frequency
• Analog Outputs – Off
• Execution Parameter – 10 Hz (see Section 10.3 and B.1)
• Trigger Source – Internal Clock (see Section 8, 9, and B.1)
• SDM Address – 3 (see Section 3.2, 6.1, and 10.3)
• RS-232 baud rate – 9600 bps (RS=0) (see Section 12 and Appendix B)
• Software RTS – Off (RI=0) (see Section 12 and Appendix B)
• Unprompted Output – Off (&=0) (see Appendix B)
The above settings can be changed with a PC, running the CSAT3 PC support
software (CSAT32.EXE), and the RS-232 cable. A copy of the CSAT3 PC support
software is available from the Campbell Scientific web site in the Support|Downloads
section.
4
3.2 SDM Address
TABLE 3-1. SDM Addressing Scheme
CRBasic
(base 10)
EDLOG
(base 4)
CSAT3
(hexadecimal)
0
00
0
1
01
1
2
02
2
3
03
3
4
10 4 5
11
5
6
12
6
7
13
7
8
20
8
9
21
9
10
22 A 11
23
B
12
30
C
13
31 D 14
32
E
CAUTION
Each CSAT3 on the SDM bus must have a unique address. A hex thumb
switch within the electronics box is used to change the SDM address. Remove
the lid and orient the electronics box with the connectors pointing down. The
hex thumb switch is now located in the lower right hand side of the electronics
box (see TABLE 3-1 for SDM addresses).
SDM address F (hex) is a special address used during a
Group Trigger. Do not set the hex thumb switch to SDM
address F on the CSAT3’s CPU board.
CSAT3 Three Dimensional Sonic Anemometer
4. Installation
4.1 Orientation
Datalogger
Address
Datalogger
Address
Thumb
Switch
The three components of wind are defined by a right handed orthogonal
coordinate system. The CSAT3 points into the negative x direction (see
FIGURE 4-1). If the anemometer is pointing into the wind, it will report a
positive u
In general, point the anemometer into the prevailing wind to minimize the
amount of data that is contaminated by the anemometer’s arms and other
supporting structures.
wind.
x
5
CSAT3 Three Dimensional Sonic Anemometer
CAUTION
CAUTION
1.31-inch OD Crossarm
26559 CM250 Leveling Mount
4.2 Mounting
The current mounting configuration for the CSAT3 includes a CM250
Leveling Mount, which should be mounted on the end of a 1.31-inch diameter
crossarm such as the CM20X. Mount it so that the bolt on the end points
upward, and secure it in place by tightening the set screws with the 3/16-inch
Allen wrench that came with the CM250. The CSAT3 is then mounted to the
CM250 by screwing the bolt into the anemometer block. See FIGURE 4-1.
Do not carry the CSAT3 by the arms or the strut between
the arms. Always hold the CSAT3 by the block, where
the upper and lower arms connect.
Older CSAT3s were mounted with a boom design. In this case, the sonic
anemometer is mounted to a vertical 3/4-inch diameter US bore pipe with a
3/4-inch by 3/4-inch crossover fitting (pn 1017). The fitting is included with
the CSAT3. The fitting will accommodate up to a 1-inch outside diameter
pipe. Attach the crossover fitting to the vertical pipe and lightly tighten the
vertical set screws. Insert the horizontal mounting arm into the crossover
fitting and lightly tighten the horizontal set screws. Point the horizontal arm
into the prevailing wind. Tighten all the fitting set screws. Mount the
anemometer head to the horizontal arm. Lightly tighten the bolt underneath the
anemometer block (see FIGURE 4-2, FIGURE 4-3, and FIGURE 4-4).
Over-tightening bolts will damage or deform the
mounting hardware.
Attach the electronics box to the body of the tripod or tower. Make sure the
connectors are pointing downward and the CSAT3 label is right-side-up. Use a
1/2-inch wrench to tighten the nuts. Connect the cable from the anemometer
head to the connector on the electronics box labeled Transducer Head.
6
FIGURE 4-1. CSAT3 coordinate system and current captive mounting
hardware (s/n 0631 to current)
CSAT3 Three Dimensional Sonic Anemometer
8915 CSAT3 Boom
FIGURE 4-2. CSAT3 coordinate system and captive mounting
hardware (s/n 0631 to current)
FIGURE 4-3. CSAT3 coordinate system, captive mounting hardware,
and cup washer (s/n 0107 to 0630)
7
CSAT3 Three Dimensional Sonic Anemometer
FIGURE 4-4. CSAT3 coordinate system and original noncaptive
mounting hardware (s/n 0107 to 0630)
4.3 Leveling
4.4 Fine Wire Thermocouple
5. Wiring
Over flat level terrain, adjust the anemometer head so that the bubble within
the level is in the bullseye. Over sloping terrain, adjust the anemometer head
so that the horizontal surface that the bubble level is mounted on is parallel to
the terrain. Firmly grasp the sonic anemometer block, loosen the bolt
underneath the block, and adjust the head accordingly. Finally, tighten the bolt
with a 9/16-inch wrench.
A fine wire thermocouple (model FW05 and FWC-L35) can be mounted to the
side of the anemometer block to measure temperature fluctuations. Attach the
female connector from the FWC-L35 to the side of the anemometer with the
short screw (#2-56 0.437 inch, pn 3514) that was provided with the
thermocouple cover. Insert the male connector of the FW05 into the female
connector of the FWC-L35. Finally, attach the thermocouple cover to the
anemometer block, using the thumb screw, so that both the FW05 and FWCL35 connectors are covered.
There are four military style connectors on the CSAT3 electronics box. They
are labeled as +12V SDM, RS-232, Transducer Head, and Analog Output.
Connect the cable from the anemometer head to the electronics box labeled
Transducer Head. The anemometer head cable is 2.13 m (7 ft) in length. Each
of the signal cables is 7.62 m (25 ft) in length. Connect the appropriate signal
cable to the electronics box. See the TABLE 5-1 through TABLE 5-8 for
details on the wire color scheme.
8
CSAT3 Three Dimensional Sonic Anemometer
TABLE 5-1. CSAT3 Power
Battery
Terminal
Description
Color
Pin
Positive
12 Vdc
Red
A
Negative
Power Reference
Black
B
TABLE 5-2. CSAT3 SDM Output to a
Channel
Description
Color
Pin
SDM-C1
SDM Data
Green
D
SDM-C2
SDM Clock
White
C
SDM-C3
SDM Enable
Brown E G
Digital Ground
Black
F
G
Shield
Clear
nc
TABLE 5-3. CSAT3 SDM Output to a
Channel
Description
Color
Pin
C1
SDM Data
Green D C2
SDM Clock
White C C3
SDM Enable
Brown
E
G
Digital Ground
Black F G
Shield
Clear
nc
CAUTION
NOTE
NOTE
The CSAT3 electronics box contains unique calibration
information for its respective sensor head. Do not
mismatch CSAT3 sensor heads and electronics. Doing
so will result in erroneous wind and speed of sound
measurements.
Before extending the SDM signal cable, read Appendix D.
Short haul modems, wire or fiber optic, may be used to lengthen
the RS-232 communications cable. Short haul modems do not
include an RTS signal. The CSAT3’s RS-232 drivers can be
asserted by a software setting in the CSAT3. This setting will
always power the RS-232 drivers, independent of the RTS line.
Spark gaps (model 6536 and 6361) may be required to protect
against transients when using wire short haul modems. Spark gap
protection is not needed with fiber optic short haul modems.
CR3000, CR5000, and CR9000X Datalogger
CR1000, CR800/850, CR23X and CR10(X) Datalogger
9
CSAT3 Three Dimensional Sonic Anemometer
TABLE 5-4. CSAT3 SDM Output to a
Channel
Description
Color
Pin
1H
SDM Data
Green
D
C1
10 K resistor to 1H
C2
SDM Clock
White
C
C3
SDM Enable
Brown E
Digital Ground
Black F
Shield
Clear
nc
TABLE 5-5. CSAT3 SDM Output to a
CR9000
9080 DB9 Pin
Datalogger
Description
Color
Pin 8 SDM Data
Green D 7
SDM Clock
White C 6
SDM Enable
Brown
E
2
Digital Ground
Black/Clear
F/nc
TABLE 5-6. CSAT3 RS-232 Output
CSAT3 (DCE)
DB9 Pin
PC (DTE)
DB9 Pin
Color
Pin
2 (TxD)
→
2 (RxD)
Red
B
3 (RxD)
←
3 (TxD)
White
C
5 (gnd)
5 (gnd)
Green
E
7 (CTS)
←
7 (RTS)
Brown G 8 (RTS)
→
8 (CTS)
Black
H
TABLE 5-7. CSAT3 Analog Output Wiring
Description
Color
Pin
ux sig high
Brown
A
ux sig low
Black
E
uy sig high
Red B uy sig low
Black
E
uz sig high
Green
C
uz sig low
Black E c sig high
White D c sig low
Black E shield
Clear
nc
21X Datalogger
CR9000 Datalogger
Pin Out
10
TABLE 5-8. FW05/FWC-L35 Fine
Description
Color
Signal High
Purple
Signal Low
Red
TABLE 6-1. CSAT3 Outputs
SDM
RS-232
Analog
Typical
Current Drain
@ 10 Hz
51 mA
89 mA
99 mA
External
Source
Output
Range
Diagnostics
Available
yes
yes
no
6. CSAT3 Outputs
The CSAT3 has three signal outputs: SDM, RS-232, and analog. Campbell
Scientific recommends that the SDM output be used whenever possible, followed
by RS-232, and finally analog. TABLE 6-1 summarizes the difference between
the three output options. In general SDM communications has the following
advantages: lowest CSAT3 current drain, best control and diagnostics, and
highest data resolution.
CSAT3 Three Dimensional Sonic Anemometer
Wire Thermocouple
6.1 SDM Output
SDM is a Campbell Scientific communication protocol used between a
Campbell Scientific datalogger and a smart sensor. TABLE 6-2 lists all the
Campbell Scientific dataloggers that support SDM communications, along with
the required datalogger OS/PROM and CSAT3 embedded code.
Trigger
Dynamic
@ 12 Vdc
yes
19 bit
@ 12 Vdc
yes
19 bit
@ 12 Vdc
no
12 bit
11
CSAT3 Three Dimensional Sonic Anemometer
TABLE 6-2. SDM Compatible Dataloggers
Datalogger
Model
Datalogger PROMs or
Operating System (OS)
Requires CSAT3
embedded code
21X 1K
6145-3, 6146-5, 10006-1
2.1 or >
21X 2K
6148-5, 6149-7, 6070-64
2.1 or >
CR10 2K
5954-396
2.1 or >
CR10 4K
Library Special
2.1 or >
CR10X
OS 1.4 or >
2.1 or >
CR23X
All OS
2.1 or >
CR9000
2.01 or >
2.1 or >
CR5000
All OS
3.0 or >
CR9000X
All OS
3.0 or >
CR1000
All OS
3.0 or >
CR3000
All OS
3.0 or >
CR800/850
All OS
3.0 or >
6.1.1 CRBasic Dataloggers
SDM is a Campbell Scientific communication protocol used between a
Campbell Scientific datalogger and a smart sensor. This protocol uses SDM
dedicated control ports (CR3000, CR5000, and CR9000X) or multipurpose
control ports (CR1000, CR800/850) to communicate with the CSAT3. SDM
protocol allows synchronized measurement and rapid communication between
a datalogger and the CSAT3. The CRBasic datalogger instruction, CSAT3 () is
used to communicate with the CSAT3 over the SDM bus.
6.1.2 EDLOG Dataloggers
SDM is a Campbell Scientific communication protocol used between a
Campbell Scientific dataloggers and a smart sensor. This protocol uses SDM
dedicated control ports (CR23X) or multipurpose control ports (21X or
CR10(X)) to communicate with the CSAT3. With a 21X, single ended analog
input channel 1 (labeled 1H) and a 10 K resistor is used in conjunction with
control port 1. SDM protocol allows synchronized measurement and rapid
communication between a datalogger and the CSAT3. The EDLOG datalogger
instruction, SDM-CSAT3 (P107), is used to communicate with the CSAT3
over the SDM bus.
6.1.3 CR9000
SDM communications between the CR9000 and CSAT3 is achieved via the 9
pin CSI serial I/O port on the 9080 peripheral and memory card. The CR9000
instruction CSAT3() is used to communicate with the CR9000 over the SDM
bus.
12
6.2 RS-232 Output
TABLE 6-3. Calibration for Analog Outputs
Slope
(m s–1 V–1)
Slope
(m s–1 V–1)
(m s–1)
ux
6.5536
13.1072
0
uy
6.5536
13.1072
0
uz
1.6384
1.6384
0
c
6.5536
6.5536
340
The Windows PC support software (CSAT32.EXE) can be used to graph the
CSAT3 data in real time or collect time series via the RS-232 serial port. A
copy of the CSAT3 PC software is available from the Campbell Scientific web
site in the Support|Downloads section. This software is intended as a
diagnostic tool, rather than part of a long term data acquisition system.
Appendix B contains detailed information on the CSAT3 RS-232 commands.
An example of an elementary Visual Basic program to configure and collect
data from a CSAT3 is available from the Campbell Scientific web site in the
Support|Downloads section.
6.3 Analog Output
The anemometer can be programmed to output four analog signals that
correspond to u
output is enabled using the Windows CSAT3 PC support software
(CSAT32.EXE) using the PC’s and CSAT3’s RS-232 serial port. The u
components of wind have two output ranges, low range (±32.768 m s
high range (±65.536 m s
software. Low range is adequate to measure wind speeds ±32.768 m s
TABLE 6-3 gives the multipliers and offset for all the anemometer outputs in
–1
m s
.
CSAT3 Three Dimensional Sonic Anemometer
, uy, uz, and c. These signals range ±5000 mV. The analog
x
x
–1
–1
). These ranges are changed using the support
) and
–1
.
and uy
Low Range
When analog outputs are used, the anemometer uses its internal timer to trigger
the wind measurements. Thus, the wind measurements can be skewed in time
±1/2 the data acquisition system’s scan interval from other analog
measurements, e.g. temperature or humidity. Recall that the CSAT3 analog
outputs also have a two measurement pipeline delay.
7. Operational Principles
7.1 Embedded Code Version 4
The CSAT3 measures wind speeds and the speed of sound by determining the
time of flight of sound between pairs of transducers, as described in Appendix
C. However, unlike many other commercial anemometers, it does not use
simple threshold detection to determine the ultrasonic times of flight. Instead,
it uses advanced digital signal processing techniques to determine the arrival of
the transmitted ultrasonic signal. In comparison to other systems, the digital
signal processing techniques result in more accurate, lower noise
measurements.
High Range
Offset
13
Loading...