Campbell EC155 User manual

EC155
CO2and H2O
Closed-Path Gas Analyzer
and EC100 Electronics with
Optional CSAT3A 3D Sonic Anemometer
User Manual
Issued 25.3.13
Copyright ©2010-2013 Campbell Scientific Inc.
Printed under licence by Campbell Scientific Ltd.
CSL 905

Guarantee
This equipment is guaranteed against defects in materials and workmanship.
This guarantee applies for twelve months from date of delivery. We will
repair or replace products which prove to be defective during the guarantee
period provided they are returned to us prepaid. The guarantee will not apply
to:
•Equipment which has been modified or altered in any way without the
written permission of Campbell Scientific
•Batteries
•Any product which has been subjected to misuse, neglect, acts of God or
damage in transit.
Campbell Scientific will return guaranteed equipment by surface carrier
prepaid. Campbell Scientific will not reimburse the claimant for costs incurred
in removing and/or reinstalling equipment. This guarantee and the Company’s
obligation thereunder is in lieu of all other guarantees, expressed or implied,
including those of suitability and fitness for a particular purpose. Campbell
Scientific is not liable for consequential damage.
Please inform us before returning equipment and obtain a Repair Reference
Number whether the repair is under guarantee or not. Please state the faults as
clearly as possible, and if the product is out of the guarantee period it should
be accompanied by a purchase order. Quotations for repairs can be given on
request. It is the policy of Campbell Scientific to protect the health of its
employees and provide a safe working environment, in support of this policy a
“Declaration of Hazardous Material and Decontamination” form will be
issued for completion.
When returning equipment, the Repair Reference Number must be clearly
marked on the outside of the package. Complete the “Declaration of
Hazardous Material and Decontamination” form and ensure a completed copy
is returned with your goods. Please note your Repair may not be processed if
you do not include a copy of this form and Campbell Scientific Ltd reserves
the right to return goods at the customers’ expense.
Note that goods sent air freight are subject to Customs clearance fees which
Campbell Scientific will charge to customers. In many cases, these charges are
greater than the cost of the repair.
Campbell Scientific Ltd,
Campbell Park, 80 Hathern Road,
Shepshed, Loughborough, LE12 9GX, UK
Tel: [phone]
Fax: [phone]
Email: [email protected]
www.campbellsci.co.uk

PLEASE READ FIRST
About this manual
Please note that this manual was originally produced by Campbell Scientific Inc. primarily for the
North American market. Some spellings, weights and measures may reflect this origin.
Some useful conversion factors:
Area: 1 in2(square inch) = 645 mm2
Length: 1 in. (inch) = 25.4 mm
1 ft (foot) = 304.8 mm
1 yard = 0.914 m
1 mile = 1.609 km
Mass: 1 oz. (ounce) = 28.35 g
1 lb (pound weight) = 0.454 kg
Pressure: 1 psi (lb/in2) = 68.95 mb
Volume: 1 UK pint = 568.3 ml
1 UK gallon = 4.546 litres
1 US gallon = 3.785 litres
In addition, while most of the information in the manual is correct for all countries, certain information
is specific to the North American market and so may not be applicable to European users.
Differences include the U.S standard external power supply details where some information (for
example the AC transformer input voltage) will not be applicable for British/European use. Please
note, however, that when a power supply adapter is ordered it will be suitable for use in your country.
Reference to some radio transmitters, digital cell phones and aerials may also not be applicable
according to your locality.
Some brackets, shields and enclosure options, including wiring, are not sold as standard items in the
European market; in some cases alternatives are offered. Details of the alternatives will be covered in
separate manuals.
Part numbers prefixed with a “#” symbol are special order parts for use with non-EU variants or for
special installations. Please quote the full part number with the # when ordering.
Recycling information
At the end of this product’s life it should not be put in commercial or domestic refuse
but sent for recycling. Any batteries contained within the product or used during the
products life should be removed from the product and also be sent to an appropriate
recycling facility.
Campbell Scientific Ltd can advise on the recycling of the equipment and in some cases
arrange collection and the correct disposal of it, although charges may apply for some
items or territories.
For further advice or support, please contact Campbell Scientific Ltd, or your local agent.
Campbell Scientific Ltd, Campbell Park, 80 Hathern Road, Shepshed, Loughborough, LE12 9GX, UK
Tel: [phone] Fax: [phone]
Email: [email protected]
www.campbellsci.co.uk

i
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. Introduction..................................................................1
2. Cautionary Statements................................................1
3. Initial Inspection ..........................................................2
4. Overview.......................................................................2
5. Specifications ..............................................................3
5.1 Measurements ..........................................................................................3
5.2 Output Signals..........................................................................................5
5.3 Physical Description.................................................................................6
5.4 Power Requirements ................................................................................8
6. Installation....................................................................8
6.1 Mounting..................................................................................................8
6.2 Plumbing................................................................................................11
6.2.1 Flow..............................................................................................11
6.2.2 Pressure ........................................................................................ 11
6.2.3 Filtration.......................................................................................12
6.2.4 Plumbing Connections .................................................................12
6.2.4.1 Sample Intake .....................................................................10
6.2.4.2 Pump...................................................................................10
6.2.4.3 Zero/Span............................................................................10
6.3 Wiring and Connections.........................................................................13
7. Settings ......................................................................16
7.1 Factory Defaults.....................................................................................16
7.2 Details .................................................................................................... 17
7.2.1 SDM Address...............................................................................17
7.2.2 Bandwidth ....................................................................................17
7.2.3 Unprompted Output......................................................................17
7.2.4 Unprompted Output Rate.............................................................17
7.2.5 RS485 Baud Rate .........................................................................17
7.2.6 Analogue Output..........................................................................17
7.2.7 ECMon Update Rate ....................................................................18
7.2.8 Temperature Sensor......................................................................18
7.2.9 Fixed Temperature Value.............................................................18
7.2.10 Pressure Sensor ..........................................................................18
7.2.10.1 Pressure Gain....................................................................18
7.2.10.2 Pressure Offset..................................................................18
7.2.10.3 Fixed Pressure Value........................................................19
7.2.11 Differential Pressure...................................................................19
7.2.12 Heater Control............................................................................19

ii
7.3 ECMon ...................................................................................................19
7.4 Device Configuration Utility..................................................................21
8. EC100 Outputs...........................................................21
8.1 SDM Output...........................................................................................22
8.2 USB or RS-485 Output ..........................................................................22
8.3 Analogue Outputs...................................................................................24
9. Maintenance...............................................................24
9.1 Routine Maintenance..............................................................................24
9.2 Intake Filter Replacement.......................................................................25
9.3 Cleaning Analyzer Windows..................................................................25
9.4 Zero and Span.........................................................................................28
9.5 Replacing the EC155 Desiccant/CO2Scrubber Bottles..........................32
9.6 Factory Recalibration .............................................................................33
10. Datalogger Programming with CRBasic................33
10.1 EC100() Instruction..............................................................................34
10.2 EC100Configure() Instruction..............................................................37
10.3 Example CRBasic Program..................................................................40
11. Theory of Operation.................................................41
Appendices
A. Filter Bandwidth and Time Delay...........................A-1
B. Useful Equations.....................................................B-1
C. MSDS (Material Safety Data Sheet) Forms............C-1
C.1 Magnesium Perchlorate MSDS ...............................................................1
C.2 Decarbite MSDS......................................................................................2
Figures
5-1. Dimensions of EC155 Analyzer Head with Optional Heated Intake......7
5-2. Dimensions of EC155 Analyzer Head without Optional Heated Intake.7
6-1. Exploded view of mounting the EC155 Gas Analyzer and the
CSAT3A Sonic Head...........................................................................9
6-2. EC100 Enclosure Mounting Bracket mounted on a vertical mast (left)
and a tripod leg (right).......................................................................10
6-3. Exploded view of mounting the EC100 Enclosure...............................11
6-4. End views of the analyzer showing the sample intake (optional
heated intake not shown), pump outlet, and zero/span intake ...........12
6-5. EC100 Electronics Front Panel. The picture on the left shows the
panel as it is shipped from the factory (enhanced barometer shown).
The picture on the right shows the panel after the user has done all
the wiring and made all connections (basic barometer used) ............13
6-6. Bottom of EC100 Enclosure .................................................................14
7-1. The Main Window of ECMon..............................................................20
7-2. The Setup Window in ECMon..............................................................20
7-3. The ECMon Status Window.................................................................20

iii
8-1. An example of USB data output in terminal mode............................... 23
9-1. The underside of the optional heated intake......................................... 25
9-2. The EC155 Analyzer with the top shell open.......................................26
9-3. By loosening the thumbscrews above the sample cell, the latches
may be spun from position A to position B, thus freeing the struts
of the analyzer ...................................................................................27
9-4. The EC155 Analyzer and Sample Cell with shell top open..................27
9-5. Analyzer removed from sample cell and shell......................................28
9-6. ECMon Display Window showing real-time CO2and H2O.................29
9-7. ECMon Zero/Span Window .................................................................31
9-8. Replacing the source housing desiccant/scrubber bottle.......................33
9-9. Replacing the detector housing desiccant/scrubber bottle.................... 33
A-1. Frequency Response of the EC100 Filter at various bandwidths ......A-2
A-2. Frequency response comparison of the EC100 10-Hz bandwidth
and a 50-msec moving average .......................................................A-3
Tables
6-1. EC100 SDM output to a Campbell Scientific CR1000, CR3000, or
CR5000 Datalogger...........................................................................15
7-1. Factory Default Settings ....................................................................... 16
8-1. USB and RS-485 Output Elements.......................................................23
8-2. Multipliers and Offsets for Analogue Outputs......................................24
10-1. Output Modes for EC100 Instruction .................................................34
10-2. Bits in the Sonic Diagnostic Flag .......................................................35
10-3. Bits in the Gas Diagnostic Flag ..........................................................36
10-4. ConfigCmd Values for Setting and Retrieving Settings.....................38
A-1. Filter Time Delays for Various Bandwidths......................................A-3

Campbell Scientic, Inc. | 815 W 1800 N | Logan, Utah 84321-1784 | [phone] | www.campbellsci.com
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Printed 6/1/2011
EC155 Packing Information
The EC155 components are placed in a foam cutout that helps protect them from damage during shipment. The
EC155 should look like one of the photographs below, depending on the sample cell option ordered. After unpacking,
it is recommended to save the foam cutout as the EC155 components should be placed in the foam cutout whenever
the EC155 is transported to another location.
Note: Another box containing the Sonic Head and its components will also be shipped with the EC155 analyzer if
Sensing Head Option –SH has been ordered.
Extra Pocket for End
User Added Parts
EC100 Electronics
with Enclosure
#27007 CD-ROM
Certificate of Conformance #25995 EC100
Enclosure Mounting #26559
Boom Adapter
Gas Sensor Head Cable
Sample Cell Cable
#26563 USB Cable
Sample Cell with Intake
and Gas Sensor Head
(if ordered –SI)
#26570 EC155
Mounting Platform

Figure 1. EC155 with Sample Cell Option -SI

Extra Pocket for End
User Added Parts
EC100 Electronics
with Enclosure
#27007 CD-ROM
Certificate of Conformance #25995 EC100
Enclosure Mounting #26559
Boom Adapter
Gas Sensor Head Cable
Sample Cell Cable
#26563 USB Cable
Sample Cell with
Gas Sensor Head
(if ordered –SN)
#26570 EC155
Mounting Platform

Figure 2. EC155 with Sample Cell Option -SN

1
EC155 CO2and H2O Closed-Path Gas
Analyzer and EC100 Electronics with
Optional CSAT3A 3D Sonic Anemometer
1. Introduction
The EC155 is an in-situ, closed-path, mid-infrared absorption gas analyzer that
measures molar mixing ratios of carbon dioxide and water vapour, along with
sample cell temperature and pressure. The EC155 may be used in conjunction
with the CSAT3 sonic anemometer, which measures orthogonal wind
components.
Before using the EC155, please study
•Section 2, Cautionary Statements
•Section 3, Initial Inspection
•Section 6, Installation
More details are available in the remaining sections.
2. Cautionary Statements
•DANGER:
oThe scrubber bottles (see Section 9.5, Replacing the EC155
Desiccant/CO2Scrubber Bottles) contain the strong oxidizing agents
sodium hydroxide (caustic soda, NaOH) and anhydrous magnesium
perchlorate (Mg(ClO4)2).
Avoid direct contact with the chemicals.
Ensure your work area is well ventilated and free of
reactive compounds, including liquid water.
Store used chemical bottles in a sealed container until
disposal.
Dispose of chemicals and bottles properly.
Materials Safety Data Sheets (MSDS) are provided in
Appendix C. MSDS are updated periodically by chemical
manufacturers. Obtain current MSDS at
www.campbellsci.com.
•WARNING:
oDo not carry the EC155 or CSAT3A by the arms or carry the EC155
by the strut between the arms. Always hold them by the block,
where the upper and lower arms connect.
oHandle the EC155 carefully. The optical source may be damaged by
rough handling, especially while the analyzer is powered.
oOver-tightening bolts will damage or deform the mounting hardware.

EC155 CO2and H2O Closed-Path Gas Analyzer and EC100 Electronics
with Optional CSAT3A 3D Sonic Anemometer
2
•CAUTION:
oGrounding the EC100 measurement electronics is critical. Proper
grounding to earth (chassis) will ensure maximum ESD (electrostatic
discharge) protection and improve measurement accuracy.
oDo not connect or disconnect the gas analyzer or sonic connectors
while the EC100 is powered.
oThe SDM, USB, and RS-485 output options include EC155
diagnostic data. Be aware that the absence of diagnostic data in the
analogue output option could make troubleshooting difficult and
may lead to the user not being aware of potential problems with the
instrumentation (see Section 8, EC100 Outputs).
oResting the analyzer on its side during the zero-and-span procedure
may result in measurement inaccuracy.
oWhen cleaning the gas-analyzer window, make sure the alcohol and
any residual water completely evaporate before proceeding with the
zero-and-span procedure (see Section 9.3, Cleaning Analyzer
Windows).
3. Initial Inspection
Upon receipt of your equipment, inspect the packaging and contents for damage.
File damage claims with the shipping company.
4. Overview
The EC155 is a closed-path, mid-infrared absorption analyzer that measures molar
mixing ratios of carbon dioxide and water vapour, along with sample cell
temperature and pressure. It has been designed specifically for eddy covariance
flux measurements and may be used in conjunction with the CSAT3A 3D sonic
anemometer head. The analyzer has a rugged, aerodynamic design with low
power requirements, making it suitable for field applications.
The EC155 gas analyzer connects directly to the EC100 electronics, which
computes real-time CO2and H2O molar mixing ratios of the air inside the sample
cell of the analyzer. A CSAT3A sonic anemometer head may also be connected
to the EC100.
The EC155 has been designed specifically to address issues of aerodynamics,
power consumption, performance during precipitation events, ambient air density
fluctuations, temporal synchronicity, and system integration. Its unique design
enables it to operate with only 4.8 W power; it has minimal spatial displacement
from the sample volume of a CSAT3A sonic anemometer; the EC100 electronics
synchronize data from the EC155 and CSAT3A; and the analyzer is easily
integrated into the CPEC200 closed-path eddy covariance system, a turn-key
system containing data acquisition and control instrumentation, a sample pump,
and optional zero-and-span valve module.

User Manual
3
5. Specifications
5.1 Measurements
Features
•To compute carbon dioxide, water vapour, and sensible heat fluxes using the
eddy-covariance method, the EC155 measures:
oabsolute carbon dioxide
owater vapour mixing ratios
othree-dimensional wind speed (requires CSAT3A)
osonic air temperature (requires CSAT3A)
osample cell temperature
obarometric pressure.
These measurements are required to compute carbon dioxide and water vapour
fluxes using the:
•Standard outputs:
oCO2mixing ratio, H2O mixing ratio
ogas analyzer diagnostic flags
ocell temperature, cell pressure
oCO2signal strength, H2O signal strength
odifferential pressure
oair temperature and air pressure are auxiliary sensor inputs.
•Additional outputs:
oux, uy, and uzorthogonal wind components
osonic temperature (based on the measurement of c, the speed of
sound)
osonic diagnostic flags.
Compatibility: CR1000
CR3000
CR5000
Measurement
Rate: 100 Hz
Output bandwidth2:5, 10, 12.5, 20, or 25 Hz
Output rate2:5 to 50 Hz
Operating temperature: -30oto 50oC
Gas analyzer
Measurement precision1
CO2 density: 0.2 mg·m-3 (0.15 µmol·mol-1)
H2O density: 0.00350 g·m-3 (0.006 mmol·mol-1)
Factory calibrated range
CO2:0 to 1830 mg·m-3 (0 to 1000 ppm)
H2O: 0 to 83 ppt (-60oto 37oC dew point)
Analyzer temp: -30oto 50oC
Baro pressure: 70 to 106 kPa
CO2performance
Zero max drift3:±0.55 mg·m-3·°C-1 (±0.3 μmol·mol·°C-1)
Gain Drift: ±0.1% of reading·°C-1 (maximum)
Sensitivity to H2O: ±5.6 x 10-5 µmol CO2·mol-1 H2O (max)

EC155 CO2and H2O Closed-Path Gas Analyzer and EC100 Electronics
with Optional CSAT3A 3D Sonic Anemometer
4
H2O performance
Zero max drift3:±0.037 g·m-3·°C-1 (±0.05 mmol·mol-1·°C-1)
Gain Drift: ±0.3% of reading·°C-1 (maximum)
Sensitivity to CO2:±0.05 mol H2O·mol-1 CO2 (maximum)
CSAT3A sonic measurement precision4
ux:1 mm·s-1
uy:1 mm·s-1
uz:0.5 mm·s-1
Sonic temperature: 0.025oC
CSAT3A sonic accuracy5
Offset error
ux, uy:< ±8 cm·s-1
uz:< 4 cm·s-1
Gain error
Wind vector ±5° horizontal: < ±2% of reading
Wind vector ±10° horizontal: < ±3% of reading
Wind vector ±20° horizontal: < ±6% of reading
CSAT3A sonic reporting range
Full scale wind: ±65.553 m/s
Sonic temperature: -50° to +60°C
Sample cell sensors6
Barometer
Internal basic barometer
Manufacturer: Freescale
Model: MPXAZ6115A
Accuracy: ±2.2 kPa (0oto 85oC)
Linear rise: ±2.2 kPa at 0oC to ±5.5 kPa at -30oC
Optional enhanced barometer:
Manufacturer: Campbell Scientific
Model: CS106 (Vaisala PTB110)
Accuracy: ±0.85 kPa (0oto 60oC)
Linear rise: 0.85 kPa at 0°C to 1.90 kPa at -30°C
Temperature sensor:
Manufacturer: BetaTherm
Model: 100K6A1A Thermistor
Accuracy: ±0.15oC (0oto 50oC)
1 noise rms, assumes:
o25°C
o85 kPa
o19 mmol/mol H2O concentration
o326 mmol/mol CO2concentration
o25 Hz bandwidth.
2 user selectable
3 -30° to 50°C
4 noise rms
5 assumes:
o-30° to +50°C
owind speed <30 m·s-1
oazimuth angles between ±170°
6 refer to manufacturer’s product brochure or manual for details

User Manual
5
5.2 Output Signals
Features
•EC100 electronics outputs data using:
oCS SDM
oRS-485
oUSB
oAnalogue out
Digital
SDM (Synchronous Device for Measurement)1
Data type: FLOAT
RS-485
Data type: ASCII
Output Rate: 5 to 50 Hz (user selectable)
Baud rate: 1200 to 230400 bps (user selectable)
USB
Data type: ASCII
Output rate: 5 to 50 Hz (user selectable)
Analogue (two outputs for CO2and H2O molar mixing ratios)
Voltage range: 0 mV to 5000 mV
Resolution: 76 µV (16 bit)
Update rate: 150 Hz
Accuracy (at 25oC): ±3 mV
CO2mixing ratio equation: µmol/mol = 211.27 (Vout) – 56.34
Full scale range: -56 to 1000 µmol/mol
H2O mixing ratio equation: mmol/mol = 11.31 (Vout) – 3.04
Full scale range: -3 to 53 mmol/mol
1Synchronous Device for Measurement. A Campbell Scientific, Inc. proprietary serial interface for
datalogger to peripheral and sensor communication. See Section 8.1, SDM Output for details.

EC155 CO2and H2O Closed-Path Gas Analyzer and EC100 Electronics
with Optional CSAT3A 3D Sonic Anemometer
6
5.3 Physical Description
Sample cell volume: 5.9 cm3(0.36 in3)
Sample cell length: 12.0 cm (4.72 in)
Sample cell diameter: 7.94 mm (0.313 in)
Spatial separation between
EC155 optional intake and
CSAT3A sample volume: 15 cm (6.0 in)
Length of tubing from tip
of optional heated intake
to sample cell: 58.4 cm (23 in)
Inside diameter of intake tubing: 2.67 mm (0.105 in)
Dimensions
Analyzer: 42.7 cm x 7.4 cm x 10.1 cm (16.8 in x
9 in x 4.0)
Length of optional intake: 38.1 cm (15.0 in)
EC100 electronics: 24.1 cm x 35.6 cm x 14 cm (9.5 in x 14 in
x 5.5 in)
Cable length: 3 m (9.8 ft) from analyzer to EC100
electronics
Weight
Analyzer: 3.9 kg (8.5 lbs)
Mounting hardware: 0.4 kg (0.9 lbs)
EC100 electronics and
enclosure: 3.2 kg (7 lbs)
Connections
Pump: 3/8 inch Swagelok
Zero/Span: 1/4 inch Swagelok
Sample Intake: 1/8 inch Swagelok or Optional Heated
Intake Assembly

User Manual
7
Figure 5-1. Dimensions of EC155 analyzer head with optional heated intake
Figure 5-2. Dimensions of EC155 analyzer head without optional heated intake

EC155 CO2and H2O Closed-Path Gas Analyzer and EC100 Electronics
with Optional CSAT3A 3D Sonic Anemometer
8
5.4 Power Requirements
Voltage supply: 10 to 16 Vdc
Power at 25oC including CSAT3A: 4.8 W
Power at 25oC excluding CSAT3A: 4.0 W
Power at 25oC in power-down
mode (CSAT3A fully powered
and EC155 in stand-by): 3.0 W
Power for optional heated intake: set by user, 0 to 0.7 W.
6. Installation
6.1 Mounting
The EC155 is supplied with mounting hardware to attach it to the end of a
horizontal pipe of 1.31 inch outer diameter, such as the CM202, CM204, or
CM206 crossarm (p/n #1790x). The EC155 mounting hardware also
accommodates an optional CSAT3A sonic anemometer, placing it at the proper
position when the EC155 is configured with the optional heated intake assembly.
The following steps describe the normal mounting procedure with the optional
heated intake assembly and optional CSAT3A sonic head. Other mounting
arrangements are acceptable as long as the analyzer is upright. The bottom of the
analyzer has two #6-32 UNC-thread mounting holes for applications that do not
use the EC155 mounting platform.
Refer to Figure 6-1 throughout this section.
a. Mount a CM202, CM204, or CM206 crossarm (p/n #1790X) to a tripod or
other vertical structure using a CM210 crossarm-to-pole bracket (p/n
#17767). The crossarm should be within ± 7 degrees of horizontal to allow
the CSAT3A sonic anemometer to be levelled.
Do not carry the EC155 by the intake or the CSAT3A by the
arms. Always hold the instruments by the body or base.
b. Mount the CM250 levelling mount (p/n #26559) on the end of the crossarm.
Tighten the set screws on the levelling mount.
c. Bolt the mounting platform (p/n #26570) to the CM250 levelling mount (p/n
#26559).
d. Place the EC155 gas analyzer on the mounting platform so the four rubber
feet fit into the platform holes, and tighten the captive screws located on the
bottom of the platform into the mounting holes on the bottom of the analyzer.
e. If a CSAT3A is being used, mount it on the end of the mounting platform
using the captive CSAT3A mounting bolt.
f. Level the assembly by slightly loosening the bolt in the CM250 levelling
mount. Adjust the assembly until the levelling bubble on top of the CSAT3A
is in the bulls eye. Retighten the bolt.
WARNING