LI-COR li-7200 Instruction Manual
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LI-COR li-7200 Instruction Manual

Enclosed co2/h2o gas analyzer
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Enclosed CO2/H2O
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Summary of Contents for LI-COR li-7200

  • Page 1 Enclosed CO2/H2O Gas Analyzer Instruction Manual...
  • Page 3 Germany Phone: +49 (0) 6172 17 17 771 Fax: +49 (0) 6172 17 17 799 envsales-gmbh@licor.com envsupport-gmbh@licor.com LI-COR Ltd., United Kingdom Serving Denmark, Finland, Ireland, Norway, Sweden, and UK. LI-COR Biosciences UK Ltd. St. John’s Innovation Centre Cowley Road Cambridge...
  • Page 4 LI-COR MAKES NO WARRANTY OF ANY KIND WITH REGARD TO THIS MATERIAL, INCLUDING, BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. LI-COR shall not be liable for errors contained herein or for incidental or consequential damages in connection with the furnishing, performance, or use of this material.
  • Page 5 CE Marking: This product is a CE-marked product. For conformity information, contact LI-COR Support at envsupport@licor.com. Outside of the U.S., contact your local sales office or distributor. LI-7200RS CO2 / H2O LI-7200RS Closed Path CO O Analyzer Part Name Toxic and Hazardous Substances or Elements...

  • Page 6: A Bit Of History

    Even if you do not upgrade your instrument hardware, you can use this manual to guide your use of an original LI-7200. We invite you to install the new soft- ware on older instruments. It is available for free from the LI-COR web site. We also invite your feedback—what do you like? What do you dislike? What do you...

  • Page 7: Table Of Contents

    Contents A bit of history... Section 1. General Information What’s What Spare Parts Kits Cables Calibration Certificate The SmartFlux® 2 System LI-7550 Analyzer Interface Unit Section 2. Initial Setup First Things First Installing the Gas Analyzer and Components Mounting the LI-7550 Analyzer Interface Unit Using the Insulated Intake Tube Using the Heated Intake Tube Installing the Intake Cap...
  • Page 8 Connect over Serial RS-232 Run Disconnected Dashboard Instrument Information and Logging Instrument Status and Connectivity Eddy Covariance Flux Graphs 3-10 Data Display 3-13 Configuring Eddy Covariance Measurements 3-17 Eddy Covariance Checklist 3-18 System Clock 3-21 Configuring the USB Log File 3-22 Entering the Site Description 3-23...
  • Page 9 Replacing the Thermocouples Leak Test 5-10 Cleaning the Intake Cap and Screen 5-10 Maintaining the Filter 5-11 Section 6. Troubleshooting Power On Problems Problems with the SmartFlux 2 System Ethernet Connection Problems RS-232 serial connection problems Instrument software is unresponsive Bad Temperature Readings Bad Pressure Readings Bad CO2 or H2O Readings...
  • Page 10 CO2 Signal Strength Delta Signal Strength 8-10 LI-7200RS Transfer Functions and Signal Processing 8-11 Signal Processing Bandwidth/Frequency Response 8-11 Appendix A. Specifications Appendix B. Pin Assignments Appendix C. Suppliers Appendix D. Configuration Grammar Appendix E. Warranty Appendix F. Index viii...

  • Page 11: Section 1. General Information

    Section 1. General Information The LI-7200RS is a closed path, non-dispersive infrared CO O analyzer designed for use in eddy covariance flux systems. Some of the LI-7200RS's important features include: Onboard computation of flux data in the SmartFlux 2 SystemSmartFlux 2 System, which is included as a stand- ard component.

  • Page 12: What's What

    You need the PC software to configure the instrument. Download it from Note: the LI-COR technical support web site: www.licor.com/env/support. Select your instrument and you'll find the software downloads. Spare Parts Kits The LI-7200RS sensor head spare parts kit (part 7200-028) includes accessories and replacement parts for the sensor head.

  • Page 13: Cables

    Section 1. General Information Description Qty. Part Number Sock Tip Swabs 610-05315 Replacement Temperature Thermocouple 9972-007 Insulated Intake Tube (1 m) 9972-053 Intake Cap Assembly 9972-072 Swagelok 2-micron Dust Filter 9972-073 Hex Key (7/64") 610-03745 LI-7550 Analyzer Interface Unit Spares Kit 9975-023 Control Unit Mounting Kit 9979-022...
  • Page 14 RS-232 has a standard DB-9 female connector for direct connection to a computer. Most modern computers will require an RS-232-to-USB adapter to use this cable. LI-COR provides an RS-232-to-USB adapter (part 6400-27) that has been tested to work with all LI-COR devices.

  • Page 15: Calibration Certificate

    LI-7550 at the factory. Keep this sheet in case you need to re-enter these values. You can also acquire a copy of your calibration certificate from the LI-COR support web site. The SmartFlux® 2 System...

  • Page 16: Li-7550 Analyzer Interface Unit

    Section 1. General Information LI-7550 Analyzer Interface Unit The LI-7550 Analyzer Interface Unit houses the gas analyzer electronics and a con- nector for the USB flash drive. A 16 GB industrial-rated drive is included with the instrument. There are three Ethernet connectors inside the LI-7550, two of which are connected to the external ports.
  • Page 17 Section 1. General Information Figure 1-3. LI-7550 connector panel. Figure 1-4. Pin assignments and wire colors for Power, SDM, Auxiliary Input and DAC Output cables. The lower left section describes indicators given by the USB indicator light. LI-7550 Analyzer Interface Unit...
  • Page 18 Section 1. General Information LI-7200RS Enclosed CO O Analyzer...

  • Page 19: Section 2. Initial Setup

    Section 2. Initial Setup This section describes how to mount the analyzer and accessories in a typical eddy covariance application. First Things First The following section covers the basic steps you will follow to set up the LI- 7200RS. Many of these steps are described in greater detail elsewhere in this manual.
  • Page 20 Section 2. Initial Setup Connect the Flow Module The 7200-101 Flow Module draws sample air through the LI-7200RS sensor head. Remove the Swagelok fitting from port of the head and replace it with the 3/8" plastic hose barb from the spares kit.
  • Page 21 Go to www.licor.com/env/support, select your instrument and then select Software. Download the software and install it on your computer. The program icon will be in the Programs menu under the LI-COR folder. Connect to the Instrument Launch the PC software, then select your instrument from the list and click...

  • Page 22: Installing The Gas Analyzer And Components

    Section 2. Initial Setup Installing the Gas Analyzer and Components The instrument is typically installed on a tripod or tower for eddy covariance applic- ations. This section describes how to install the instrument and its associated com- ponents. Mounting the LI-7550 Analyzer Interface Unit The mounting kit (part number 9979-022) is used to mount the LI-7550 to a tripod or other post.

  • Page 23: Using The Insulated Intake Tube

    Section 2. Initial Setup Table 2-1. Mounting kit parts. (...continued) Item Qty. Part Number Description 300-13293 Hose Clamp, 9/16” 9879-045 Mounting Plate included w/ item #4 5/16-24 × 1/2” Hex Head Bolt included w/ item #4 5/16” Flat Washer Using the Insulated Intake Tube The LI-7200RS includes an insulated 1-meter intake tube (part number 9972-042).

  • Page 24: Using The Heated Intake Tube

    The heated intake tube can be installed on any LI-7200 or LI-7200RS. If your instru- ment was manufactured before June, 2015, update the software before using the heated intake tube.
  • Page 25 Section 2. Initial Setup Installing the Cables All LI-7550s need the accessory junction splitter, so install it on the accessory con- nector. Important: Tighten the cable connectors securely. After the connectors get snug, wiggle and tighten them again to ensure a weather-tight connection. Figure 2-3.
  • Page 26 Section 2. Initial Setup Figure 2-4. The power supply splitter and Power/RS-485 adapter are required for older instruments. Installing the Insulated Intake Tube Early instruments are equipped with a 3/8" inlet fitting. It should be replaced with the ¼" fitting before installing the tube. Remove the old intake tube (if installed).
  • Page 27 Section 2. Initial Setup Install the tube in the analyzer head. Tighten all fittings securely. Attach the intake tube to a secure mount so that the analyzer is not bearing its weight. Connect the intake tube cable. It connects to the accessory junction splitter (Figure 2-3 on page 2-7). Secure the cables so that cable junctions are not bearing their weight.
  • Page 28 Section 2. Initial Setup need to clean the optical cell. Use the filter in environments that have airborne dust and pollen that can contaminate the optical cell. Important: The filter does not completely eliminate the need to regularly clean the optics.

  • Page 29: Installing The Intake Cap

    Section 2. Initial Setup Install the nut, front ferrule, and back ferrule over the short stain- less steel pipe. Be sure the tube is fully seated in the filter. Tighten the fitting to hand tight, then about ½ turn more using 9/16" and 1" wrenches. Install the nut, front ferrule, and back ferrule on the intake tube.

  • Page 30: Mounting The Sensor Head And Intake Tube

    Section 2. Initial Setup Mounting the Sensor Head and Intake Tube The LI-7200RS sensor head should be mounted to a tripod or tower using the mounting kit (part number 7900-340) or a ¾ inch IPS NuRail® swivel mount. The head should be tilted at a 10 to 15° angle toward the inlet. If the intake tube is longer than 15 cm, it should be attached to a secure element so that the analyzer is not bearing its full weight.
  • Page 31 Section 2. Initial Setup Figure 2-6. High above the plant canopy top (1.5 m or higher), mount the intake under the sonic path to minimize the horizontal sensor separation and wind flow disturbance. Figure 2-7. Close to the plant canopy top, mount the intake alongside the sonic path to minimize the vertical sensor separation.
  • Page 32 Section 2. Initial Setup Important: Do not insert the intake into the anemometer path, because sig- nificant flow disturbance to all three wind components may occur, severely affect- ing flux data quality. Or worse, the intake could completely block the transducers.

  • Page 33: Tips For Successful Use Of The Li-7200Rs

    Section 2. Initial Setup There is a gasket in the head cable connector. When tightening the connector, wiggle and push the connecter while tightening to compress the gasket. Provide a loose bend radius to allow the cable to absorb the energy of the bend- ing over a greater portion of its length.

  • Page 34: Filtering

    Filtering In situations where fine-particle filtering is required to maintain acceptable data quality a restrictive single-micron filter can be used (LI-COR part number 9967- 008). The 7200-101 Flow Module was designed specifically for low-power operation, and cannot be used with such filters. In these installations, an external pump will be required.
  • Page 35 Section 2. Initial Setup electronics. However, if your site experiences condensing conditions on a daily basis, the desiccant pack kit (part #7550-950) can help prevent condensation from forming inside the LI-7550. Desiccant Pack Components Desiccant Bottle (part #6572-055) Desiccant (part #9975-042) To use the desiccant pack: Cut open the silver Mylar bag and open the internal bag.
  • Page 36 Section 2. Initial Setup The desiccant should be sufficient for one year of operation in most environments. Replace or recharge the desiccant after one year in normal conditions or more often in extremely humid conditions (e.g., if condensing conditions occur daily). 2-18 LI-7200RS Enclosed CO O Analyzer...

  • Page 37: Using The 7550-101 Auxiliary Sensor Interface

    Section 2. Initial Setup Using the 7550-101 Auxiliary Sensor Interface The optional Auxiliary Sensor Interface (ASI) is an O-ring sealed, weatherproof junction box that can be used to connect analog inputs and/or outputs. It has con- nections for up to six analog outputs, four general purpose analog inputs, and a con- PLUGS PLUGS...

  • Page 38: Terminal Connections

    Section 2. Initial Setup Terminal Connections Terminal positions for are: analog inputs Terminal Analog Inputs Description AUX1+ Auxiliary Input 1 positive AUX1- Auxiliary Input 1 negative Ground AUX2+ Auxiliary Input 2 positive AUX2- Auxiliary Input 2 negative Ground AUX3+ Auxiliary Input 3 positive AUX3- Auxiliary Input 3 negative AUX4+...

  • Page 39: Electrical Connections

    Section 2. Initial Setup Electrical Connections All analog devices connected to the ASI must be referenced to the ground (GND) connection; some examples are shown below. All auxiliary analog input ground con- nections are internally connected together. All auxiliary analog output ground connections are internally connected together.
  • Page 40 Section 2. Initial Setup Remove the Philips screws from the corners of the ASI and remove the top cover. Remove the cap from a gland plug. Pass the wires through the cap and then through the gland plug. Insert the wire leads into the appropriate terminals. Tighten the terminals to secure the wires. Make a note of which plug the wires are passing through (e.g., A, B, C), and to which terminals the wires are connected.

  • Page 41: Section 3. Operation

    Go to www.licor.com/env/support, select your instrument and then select Software. Download the software and install it on your computer. The program icon will be in the Programs menu under the LI-COR folder. Connecting with the Analyzer Launch the software to open the window.

  • Page 42: Connect Over Ethernet

    Section 3. Operation Connect over Ethernet Figure 3-1. Option 1: Plug a standard Ethernet cable into an Ethernet port inside the LI- 7550. Plug the other end directly into a computer or computer network. Figure 3-2. Option 2: Connect to the Ethernet port on the exterior of the LI-7550 enlosure. Plug the other end (RJ45 connector) directly into a computer or computer network.
  • Page 43 Section 3. Operation Yellow indicators show that the instrument embedded software is incompatible with the PC software. You can still connect, but there may be issues. Green indicators show that the instrument embedded software is compatible with the PC software. Note: We recommend that you always use the most up-to-date software and that your PC software and the instrument embedded firmware are compatible.

  • Page 44: Connect Over Serial

    Section 3. Operation Connect over Serial RS-232 The LI-7550 RS-232 port is configured as Data Terminal Equipment (DTE) with no hardware handshaking. It is bi-directional, meaning information can be transferred both into and out of the instrument. You may need a USB to RS-232 adapter to use the serial connection. LI- Note: COR part 6400-27 is a suitable adapter.

  • Page 45: Run Disconnected

    Section 3. Operation Click the button to establish communications with the instrument. Connect Run Disconnected The PC software can be used inde- pendently of an instrument by clicking on the tab and select- Run Disconnected ing the instrument. This can be useful for training purposes, or for creating a configuration file that can then be saved and transferred to instruments in the...

  • Page 46: Dashboard

    SmartFlux System (computes fluxes on-site in real time) .ghg files, which are logged by the LI-COR eddy covariance systems, are self-contained eddy covariance files that can be processed by EddyPro in the SmartFlux System to provide fully corrected flux results.

  • Page 47: Instrument Information And Logging

    Section 3. Operation Instrument Information and Logging Information about the CO O gas analyzer is presented in this pane. Indicates the network name of the gas analyzer. Connected to: Serial number of the CO O analyzer sensor head. Head serial number: Indicates the model of the CO O analyzer.

  • Page 48: Instrument Status And Connectivity

    Section 3. Operation Instrument Status and Connectivity Instrument status information is presented in the status pane Note: The warning symbol ( ) indicates that the component is in need of atten- tion or that it is not communicating properly. Indicates the status of the CO O gas analyzer.
  • Page 49 Section 3. Operation SmartFlux Indicates the status of the SmartFlux or SmartFlux System. None: SmartFlux or SmartFlux System not connected. Serial Number of SmartFlux or SmartFlux System: Connected. Note: A warning symbol ( ) indicates "waiting to connect" or that the system has become disconnected.

  • Page 50: Eddy Covariance Flux Graphs

    Section 3. Operation Eddy Covariance Flux Graphs Click on one of the three tabs on the left side of the graphing pane. The Real Time tab provides real-time graphing of measured variables. The tab displays eddy Results covariance flux results from the SmartFlux System. The tab displays a graph Wind of wind speeds by direction.
  • Page 51 Section 3. Operation Flux (µmol/m /s; LI-7700 required), u* (m/s), (µmol/mol), O (mmol/mol), (µmol/mol; LI-7700 required). If the SmartFlux or SmartFlux System is properly configured, this Wind speed: tab presents mean wind speed by direction. sets how many days of data Duration are displayed.
  • Page 52 Section 3. Operation 3-12 LI-7200RS Enclosed CO O Analyzer...

  • Page 53: Data Display

    Section 3. Operation Data Display To change the variable(s) displayed in the data windows, click on the data value; a pop-up window appears, from which you can select the variable you Data Items want to display. The variables available for display are given in Table 3-1 on the next page. Data Display 3-13...
  • Page 54 Section 3. Operation Table 3-1. Variables available for display and logging to the USB drive. Variable Description Time Time in HH:MM:SS:MS Date Date in YY:MM:DD Sequence Number Index value, increments every 3.3 ms (1/300s) CO2 (mmol/m molar density CO2 (mg/m mass density CO2 Absorptance raw absorptance value...

  • Page 55: Co2 Signal Strength

    Section 3. Operation Table 3-1. Variables available for display and logging to the USB drive. (...continued) Variable Description Diagnostic Value 2 Diagnostic value 0 or 1 (sync clocks) CO2 Signal Strength Signal Strength (S H2O Signal Strength O Signal Strength (S Average Signal Strength (S Delta Signal Strength 7550 Auxiliary Input 1...
  • Page 56 Section 3. Operation Table 3-1. Variables available for display and logging to the USB drive. (...continued) Variable Description CH4 (µmol/mol) mole fraction (LI-7700 required) CH4 (mmol/m molar density (LI-7700 required) CH4 Signal Strength RSSI value measured by the LI-7700 (RSSI) CH4 Diagnostic Value Diagnostic value output by the LI-7700 Horizontal wind speed (m/s) as measured toward the...

  • Page 57: Configuring Eddy Covariance Measurements

    Section 3. Operation Configuring Eddy Covariance Measurements window is where you configure most of the eddy covariance system Site Setup settings. The information entered here will comprise the metadata file, which describes the system setup. The addition of the metadata file inside the .ghg file allows you to: Avoid duplicate retrieving and re-typing of information needed for processing the file from any external data source;...

  • Page 58: Eddy Covariance Checklist

    Section 3. Operation Eddy Covariance Checklist Table 3-2 below is a checklist of settings that either must be set or that we recom- mend setting before recording datasets that can be processed by the SmartFlux Sys- ® tem, SmartFlux 2 System, or EddyPro Software.
  • Page 59 Section 3. Operation Table 3-2. Checklist of mandatory and recommended EC system settings. (...continued) Software Field Recommended Setting See Section Port Port number on your SmartFlux 2 module (if using SmartFlux 2) Manufacturer: Make of anemometer Model: Model of anemometer Entering Anemometer Information on For the CSAT3, ✓...
  • Page 60 Section 3. Operation Table 3-2. Checklist of mandatory and recommended EC system settings. (...continued) Software Field Recommended Setting See Section Site Setup > CH (if using an LI-7700) Analyzer Connect to LI-7700 Select if using LI-7700 Entering LI-7700 Information on Northward Measured at site page 3-37...

  • Page 61: System Clock

    Section 3. Operation System Clock IMPORTANT: In order to synchronize instrument clocks with GPS satellites through the SmartFlux System or SmartFlux 2 System, PTP (Precision Time Pro- tocol) must be enabled. Click . Under the tab, set and the Settings Time Clock sync (PTP) Automatic time/location will be updated when the data is received from satellites.

  • Page 62: Configuring The Usb Log File

    Section 3. Operation Configuring the USB Log File Data will be logged to a USB flash drive inside the LI-7550 Analyzer Interface Unit. The USB Log File tab is where you configure the Update Rate, File Duration, and the action to take should the USB flash drive run out of space. The values to be logged to the USB flash drive from the analyzer and Biomet System datalogger are chosen under the CO O Analyzer, CH...

  • Page 63: Entering The Site Description

    Section 3. Operation Entering the Site Description tab is used to enter information about the site. This inform- Site Description ation configures the metadata file that is used for flux processing. IMPORTANT: Some entries in the gas analyzer software are required for the SmartFlux System, SmartFlux 2 System or EddyPro Software to proceed with cal- culations.
  • Page 64 Section 3. Operation between 0.6 and 0.8 times the height of the canopy. If not entered explicitly, EddyPro computes displacement height as: d = 0.67 x canopy height In the logarithmic wind profile, the roughness length is the Roughness length: height at which wind speed is zero (indicated by z ).

  • Page 65: Entering Anemometer Information

    Section 3. Operation Entering Anemometer Information The sonic anemometer tab allows you to enter information about the sonic anem- ometer, including the manufacturer and model, data output format, offset from true north, and height. Some of the available options (e.g., North Alignment) will change, depending on the chosen model.
  • Page 66 Section 3. Operation Anemometer Settings Choose the sonic anemometer manufacturer and model in the Manufacturer: menus. LI-COR supports the following sonic anemometer models: Anemometers for use with SmartFlux 2 or LI-7550 Analog Inputs Manufacturer Model(s) Campbell® Scientific CSAT3, CSAT3B Gill Instruments WindMaster™, WindMaster™...
  • Page 67 Section 3. Operation Important note on North Offset: EddyPro requires the offset with respect to geographic north as two pieces of information: The offset with respect to geographic north and the magnetic declin- ation. Currently the software does not provide an entry for magnetic declination. For the best results, enter the North Offset to magnetic North.
  • Page 68 Section 3. Operation Choose the Type Input field allows you to choose from: Type U – Horizontal wind speed (m/s) as measured toward the direction in line with the north spar (see diagram below) V – Horizontal wind speed (m/s) as measured toward the direction of 90° coun- terclockwise from the north spar W –...
  • Page 69 Section 3. Operation Type Units Other Other, m/s, cm/s, volts, K, and C m/s, cm/s, volts m/s, cm/s, volts m/s, cm/s, volts K, C, volts m/s, cm/s, volts Enter the Label The Label will appear in the file header in both the data and/or metadata files. The label cannot be changed for any of U, V, W, T , or SOS.
  • Page 70 Section 3. Operation Slope Offset Examples The units selected for each auxiliary input determine the recorded in the units label data file header, as well as the file header in the metadata file used with EddyPro. As such, it is important to convert the anemometer output from voltage to data using the multiplier and offset.

  • Page 71: Entering Co2/H2O Analyzer Information

    Section 3. Operation Example 2: You have configured the Gill WindMaster to output raw voltages for auxiliary input U over the range of ±5V, and over a full scale wind speed of -30 to +30 m/s. You want to convert the raw voltages to wind speed and output the values in units of m/s.
  • Page 72 Section 3. Operation IMPORTANT: At least one separation must be different from 0. Values are meas- ured at the site and are relative to the sonic anemometer. Entering wrong values will result in incorrect flux calculations. Measurements must be provided in the indicated units. The anemometer is the center (0, 0) of the coordinate system.
  • Page 73 Section 3. Operation Northward Separation (cm) (mandatory): North or south distance between the LI- 7500RS sample path or LI-7200RS inlet and the anemometer. Positive values if north and negative values if south of the anemometer. Eastward Separation (cm) East or west distance (mandatory): between theLI-7500RS sample path or LI- 7200RS inlet and the reference anem-...
  • Page 74 Section 3. Operation Entering the Intake Tube Dimensions In the gas analyzer software, under , enter the dimensions of the intake Site Setup tube. LI-7200RS intake tube length, in centimeters. Tube length (cm) (mandatory): LI-7200RS intake tube inside diameter, in mil- Tube diameter (mm) (mandatory): limeters.
  • Page 75 Section 3. Operation Configure the Heated Intake Tube If you are using the Heated Intake Tube, configure the power setpoint. Click the LI-7200RS menu and select and set the power setpoint. Intake Tube... Indicates whether the heated intake tube is detected [OK, Unknown, or Status: None].
  • Page 76 Section 3. Operation Configuring the Flow Module The 7200-101 Flow Module is configured through the LI-7200 Windows software from . See the 7200-101 Instruction Manual for more LI-7200 > Flow Module information. The window displays the following variables: Measured flow (SLPM): Standard Liters per Minute, mass flow.

  • Page 77: Entering Li-7700 Information

    Section 3. Operation Entering LI-7700 Information An LI-7700 Open Path CH Analyzer can be connected directly to the LI-7550 Ana- lyzer Interface Unit or can be connected through the network. Connection to the LI-7550 enables you to log LI-7700 data in the same dataset collected by the O analyzer.
  • Page 78 Section 3. Operation Enter Analyzer Information Here you specify the separation between the sonic anemometer and the LI-7700 sample volume. IMPORTANT: At least one separation must be different from 0. Values are meas- ured at the site and are relative to the sonic anemometer. Entering wrong values will result in incorrect flux calculations.

  • Page 79: Entering Biomet System Information

    Diagnostic value, an integer Entering Biomet System Information Any properly configured LI-COR Biomet system (Sutron 9210 datalogger) on the network can be connected to the LI-7550 Analyzer Interface Unit to integrate bio- met data into the dataset collected by the CO O analyzer.
  • Page 80 Section 3. Operation Software or the SmartFlux System or SmartFlux 2 System and can be used in the flux calculations. Note: See the Campbell Scientific Dataloggers Installation Guide for instructions on programing the CR3000, CR1000, or CR6 datalogger for compatibility with the SmartFlux 2 System.
  • Page 81 Section 3. Operation Note: The datalogger IP addres is a user-assigned static IP address that is also entered into the datalogger interface software (see the Campbell Scientific Data- loggers Installation Guide for more information). area on the right side of the Connection Status: Connection Status Instrument...
  • Page 82 Section 3. Operation Note: Enable the ‘Sync clock to 7550’ at to synchronize the Site Setup à Biomet datalogger and LI-7550 clocks. Refer to the Biomet Station Instruction Manual for more information. 3-42 LI-7200RS Enclosed CO O Analyzer...

  • Page 83: Connecting With The Smartflux Or Smartflux 2 System

    Section 3. Operation Connecting with the SmartFlux or SmartFlux 2 System The SmartFlux window in the GHG Windows interface software displays a list of all SmartFlux System or SmartFlux 2 Systems that are connected to your network of sensors. In this window, select your System and connect to it by clicking the Con- button.

  • Page 84: Begin Logging Data

    Section 3. Operation to the EddyPro documentation for more information. See Overview of Advanced Processing on page 3-50. Begin Logging Data Helpful tip: Your current instrument configuration can be saved for later use. Click on the button (main dashboard) and select Config Files Save Configuration Select the items in the Save Options dialog that you want to store in the con-...
  • Page 85 Section 3. Operation Stop logging Delete files from the archive (if files are present there) and continue logging Delete files from the archive first, followed by the oldest data files The file transfer program can be used to transfer files from the USB drive to your computer remotely, provided you are connected to the LI-7550 Analyzer Interface Unit via an Ethernet connection.
  • Page 86 Section 3. Operation If you log all variables at 10 Hz (10 samples per second), approximately 180 MB of data will be generated each day. Thus, the 16 GB drive can collect about 80 days of data with no compression. With compression, a daily file would be about 50 MB; the 16 GB drive can collect about 288 days of data.

  • Page 87: Transferring Logged Data

    Section 3. Operation Transferring Logged Data If the LI-7550 is connected to a network via Ethernet or a cellular modem, you can transfer files and manage data on the USB drive from a networked computer. The file transfer program is installed automatically with the gas analyzer software. Launch it by clicking the button.
  • Page 88 Section 3. Operation displays the size of the USB drive, available memory, num- USB Drive Information ber of .ghg files, number of flux results files, number of daily summary files, and the number of files in the archive. When new files are transferred, they are then moved to the archive or deleted, depending on the Transfer Options selected.

  • Page 89: Using The Smartflux System Or Smartflux 2

    Section 3. Operation Tips for Automatic Data Transfer: Set the download to begin at 00:15 (12:15 am) if you are using the SmartFlux SystemSmartFlux 2 System. That way all the logged files will be processed before the download begins. Close the application to your system tray to keep it running in the back- ground.

  • Page 90: Overview Of Advanced Processing

    Section 3. Operation Overview of Advanced Processing Advanced Mode provides you with the high-level capabilities of the EddyPro Advanced, computing fully corrected flux results in real-time with the processing options of your choice. The SmartFlux configuration file, needed to run EddyPro in Advanced mode inside the original SmartFlux or SmartFlux 2 System, is created in EddyPro 5 or higher.
  • Page 91 Section 3. Operation Configuration Steps for the SmartFlux System or SmartFlux 2 System ® SmartFlux Configuration mode inside the EddyPro Software is used to create an advanced configuration file for the SmartFlux System or SmartFlux 2 System. To use this mode, check the box, and proceed through EddyPro as you normally would.
  • Page 92 Section 3. Operation If you are creating the SmartFlux configuration file from an existing project: Click Open Project and select the project. Alter any settings that need to be changed. Configure Advanced Settings (see Overview of Advanced Processing on page 3-50). If you are using , automatic , or...
  • Page 93 This is because inside SmartFlux, EddyPro does not need any of the information that is entered in the Project Creation page. The file type (LI-COR .ghg), the use of metadata (“embedded”) and the use of biomet data (“embedded”) are all predefined settings in the SmartFlux or SmartFlux 2 System.
  • Page 94 Section 3. Operation , all processing options are active, and you can Advanced Settings > Processing Options select them as you would do in EddyPro. The only exceptions are: A. The dialogue, which activates when the or the Planar Fit Settings... Planar fit option is chosen as the Planar fit with no velocity bias...
  • Page 95 Section 3. Operation B. The , which activates when the Time lag Optimization Settings... Automatic time option is chosen as a method, only lag optimization Time lag compensation gives the option. If you want to use the automatic Time lag file available timelag optimization option in the SmartFlux or SmartFlux 2 System, you will have to load a previously created timelag optimization file at this time.
  • Page 96 Section 3. Operation ment file and more details on how to use it in the SmartFlux or SmartFlux 2 System. 3-56 LI-7200RS Enclosed CO O Analyzer...
  • Page 97 Section 3. Operation , all processing options are active, and you can Advanced Settings > Statistical Analysis select them as you would do in EddyPro with no exceptions. , most options are active, with the following exceptions: Advanced Settings > Output Files A.
  • Page 98 Section 3. Operation The additional configuration files are created by EddyPro (3.0 and above), when used in the standard desktop mode. If you have been running your EC system (the EC sytem in which you intend to use the SmartFlux System or SmartFlux 2 Sys- tem) for some time, you may have already created one or more of these files, or you may have a .ghg dataset suitable for creating them, if the corresponding imple- mentation is deemed necessary to calculate accurate fluxes (again, refer to EddyPro...
  • Page 99 Section 3. Operation Open EddyPro (5.0 or above) in SmartFlux Setup Mode. Configure everything as explained in the previous sections. In the Advanced Set- , configure tings > Spectral Corrections Corrections for low-pass filtering effects use one of the in situ methods among Horst (1997) and Ibrom et al. (2007) (the method of Fratini et al.

  • Page 100: Smartflux Results Files

    Section 3. Operation Browse to the file created in EddyPro (extension *.smartflux) and select it. After loading the file, the SmartFlux System or SmartFlux 2 System will compute flux results based upon the defined Advanced settings. Be sure to turn on data- logging first.
  • Page 101 Section 3. Operation The EddyPro summaries, typically named something like YYYY-MM-DD_EP- , include the half-hour eddy covariance flux results. This file is created at Summary the end of each day by collecting the results of each 30-minute file and placing them in a row.
  • Page 102 Section 3. Operation 3-62 LI-7200RS Enclosed CO O Analyzer...

  • Page 103: Section 4. Calibration

    Section 4. Calibration The LI-7200RS’s measurement accuracy depends upon its calibration. There are two major components to the calibration: 1) determining the values of calibration coefficients, and 2) setting zero and span. During a factory calibration, both of these steps are performed. The values of the coefficients that are determined should be valid for several years.

  • Page 104: Checking The Zero

    O, when there are large temperature changes. Note: Read the technical note called "Using CO and H O Scrubbers with LI-COR Gas Analyzers" for information about the interactions between scrub chemicals and the air. See https://www.licor.com/documents/7i418s3uhd2uamoxfmjd. Checking the Zero Flow a dry CO -free air through the optical path and check the analyzer reading in the software dashboard.

  • Page 105: Checking The Span

    Zero Gas Regulator Note: Read the technical note called "Using CO and H O Scrubbers with LI-COR Gas Analyzers" for information about the interactions between scrub chemicals and the air. See https://www.licor.com/documents/7i418s3uhd2uamoxfmjd. Checking the Span Check the CO span with a cylinder of CO...
  • Page 106 For the water vapor span, a convenient standard to use is a dew point generator such as the LI-COR LI-610. To avoid condensation problems choose a dew point temperature that is about 3 to 5 °C below the ambient temperature. Also, since water vapor sorbs and desorbs from surfaces, allow plenty of time for the reading to stabilize.

  • Page 107: Step-By-Step Calibration Instructions

    Section 4. Calibration Step-by-Step Calibration Instructions Clean the optical cell and reassemble it (see Cleaning the Optical Path on page 5-2). Disconnect the intake tube at the air inlet on the sensor head. Connect the calibration gas to the air inlet fitting using 3/8”...
  • Page 108 Zero CO IMPORTANT: Always zero the instrument before spanning (don’t span, then zero). In the PC software, click under the LI-7200 button. Calibration Verify that temperature and pressure sensors are working properly by checking their values in the dashboard. Click on the tab and view the value of Z Zero).

  • Page 109: Zero H2O

    Section 4. Calibration Zero H Now is a good time to check and set the H O zero, if needed. Click the tab, and note the present value of Z O Zero). Manual Wait for the H O reading to stabilize in the dashboard (3 or 4 minutes). The flag will turn from a red ‘X’...

  • Page 110: Considerations For Setting The Secondary Span

    Section 4. Calibration Considerations for Setting the Secondary Span If you find that after zeroing then spanning at one concentration, the instrument is not within specifications at a different concentration, a secondary span may be in order. The most common reason for doing this would be after a change in the chopper housing temperature set point.

  • Page 111: Step-By-Step Secondary H2O Span

    Section 4. Calibration Step-by-Step Secondary H O Span Zero the H O reading (see Zero H2O on page 4-7). Span the H O reading at a dew point that is just below the ambient temperature (see Span H2O on page 4-7). Flow a very low dew point through the tubing. Click on the Span 2 tab, and when stable, click Span 2 H It may take another 10 minutes or so to...
  • Page 112 Section 4. Calibration When the span is set, the value of S (or S for water) is determined. For density ρ'c in the optical path and the measured example, if there is a known CO absorptance is α ’c, then from equations 8-19 and 8-8, we can write We rewrite this in terms of a known mole fraction C’...
  • Page 113 Section 4. Calibration When a secondary span for CO is performed at a mole fraction C’ with measured absorptance ɑ ’ , then the span slope term S is computed from A new offset term S is then computed using equation 4-5, since the slope term has changed.
  • Page 114 Section 4. Calibration 4-12 LI-7200RS Enclosed CO O Analyzer...

  • Page 115: Section 5. Maintenance

    Section 5. Maintenance The section describes maintenance procedures. A good maintenance plan will ensure good performance of the instrument, reduce data gaps, and give you greater confidence that the measurements truthfully represent physical processes. FluxSuite™ Software can help immensely with your maintenance plan. Schedule When you first deploy the instrument: Check the flow drive percent and record it.

  • Page 116: Cleaning The Optical Path

    Every two years: Check the instrument calibration with one or more span gases. If it is outside the specifications, return the instrument to LI-COR for recalibration. Cleaning the Optical Path The LI-7200RS windows should be kept clean through regular maintenance. The analyzer is specifically designed to make it easy to remove and clean the cell without the use of tools.

  • Page 117: Opening The Optical Bench

    If you are using an original LI-7200, it is important to cover the upper window with an opaque cloth or your hand when the optical path is open.

  • Page 118: Replacing The Fuses

    Section 5. Maintenance Figure 5-1. Slide the top end of the sensor head away from the bottom to remove the optical path. The optical bench has a PVC insert as the optical path. You can use mild soap and water, isopropyl alcohol, vinegar, or water to clean the optical path. Do not use acet- one, ammonia, chlorine, or wire brushes to clean the path, as irreparable damage to the PVC insert can occur.

  • Page 119: Power Supply Fuse

    CO and water vapor. They bottles should be recharged with fresh chemicals annually (or every 6 months in hot, humid cli- mates). Replacement "charged" bottles are available from LI-COR in sets of three Power Supply Fuse...
  • Page 120 Section 5. Maintenance under part number 7200-950. If you want to recharge the bottles yourself, see Sup- pliers on page C-1, for a list of suppliers of Ascarite II and magnesium perchlorate. NOTE: Calibration shifts will occur if CO or H O are not kept out of the ana- lyzer housings.
  • Page 121 Section 5. Maintenance Figure 5-4. Insert the recharged bottles cap first. Make sure the caps have holes in the top. Use the retention screw to remove the bottle cover on the upper sensor head housing and insert the new, recharged bottle, cap first. Figure 5-5.

  • Page 122: Replacing The Thermocouples

    Section 5. Maintenance Note: Read the technical note called "Using CO and H O Scrubbers with LI-COR Gas Analyzers" for information about the interactions between scrub chemicals and the air. See https://www.licor.com/documents/7i418s3uhd2uamoxfmjd. Replacing the Thermocouples There are fine wire temperature thermocouples located in the air inlet and outlet ports that measure the air temperature of incoming and outgoing air.
  • Page 123 Section 5. Maintenance on the facing page). Make sure the 2 O-rings are present on the new board (the upper one is tacked on), and insert the new assembly, making sure the 2 pins are inserted into the connector. Reassemble the optical bench. Figure 5-7.

  • Page 124: Leak Test

    Section 5. Maintenance Leak Test Follow these steps to perform the leak test: Attach the sensor head to the Analyzer Control Unit. Remove the tubing from the pressure inlet on the sensor head. It is attached to the small hose barb between the Air IN and Air OUT ports.

  • Page 125: Maintaining The Filter

    Section 5. Maintenance Carefully pull the ring out of the cap with a screwdriver. If the screen does not fall out, you can lift it out with the screwdriver. Assembly is the reverse of removal. Be sure the screen and retaining ring are seated fully in the cap.
  • Page 126 Section 5. Maintenance 5-12 LI-7200RS Enclosed CO O Analyzer...

  • Page 127: Section 6. Troubleshooting

    Section 6. Troubleshooting We address common problems in this section. Power On Problems Adequate power supply? The instrument requires between 11.5 and 30 VDC (up to 30 W) to start up and 10 to 30 VDC (about 10 W) during normal operation. If the LED blinks the power supply is not sufficient to start up the instrument.

  • Page 128: Ethernet Connection Problems

    Section 6. Troubleshooting Reboot the SmartFlux 2 System by pressing the reset button. Reboot the LI-7550 Analyzer Interface Unit. System not connected to the sonic anemometer? For manually configured Anemometers, check to see that the Sonic Anem- ometer is set to the proper baud rate. Check the return signal LED lights next to the sonic anemometer data port.

  • Page 129: Rs-232 Serial Connection Problems

    Section 6. Troubleshooting Instrument not visible in software Firewall rules prohibiting the connection? Attempt to connect to the gas analyzer using the RS-232 connection. If you are able to connect as expected, the problem may be related to your computer firewall settings. In this case, you’ll need to create an exception that allows the gas analyzer through the firewall.

  • Page 130: Instrument Software Is Unresponsive

    Section 6. Troubleshooting “Parse Error” Incompatible PC and instrument software? Install new PC and instrument soft- ware. Baud rate and update rate incompatible? In the window, the Baud Rate Connect menu is used to set the baud rate at which to communicate with the instrument. The rate of data transfer is also dependent upon the maximum rate available with your computer's serial port, and the update frequency to be used while the program communicates with the instrument.

  • Page 131: Bad Temperature Readings

    Section 6. Troubleshooting Bad Temperature Readings Bad thermocouple? If the reading is -65 (or so), check the Diagnostics > General to see if both thermocouples (Inlet T and Outlet T) are working normally. Replace any bad thermocouples. Temperature source set incorrectly? You can select the source of temperature meas- urements, as described in Auxiliary Inputs on page 7-2.

  • Page 132: Bad Co2 Or H2O Readings

    LI-7200RS > Cal- match the calibration sheet for the head. You can get your ibration > Coefficients calibration information from the LI-COR web site. The Band Broadening coef- ficient should be 1.15. Signal strength OK? Under the page, check the values of...

  • Page 133: Section 7. Software Reference

    Section 7. Software Reference Menu Overview The LI-7200RS menu provides access to settings, settings, Input... Output... Cal- , and settings. ibration... PC Logging... Flow Module... Intake Tube... LI-7200RS Enclosed CO O Analyzer...

  • Page 134: Auxiliary Inputs

    Section 7. Software Reference Auxiliary Inputs There are three things to configure under Inputs Typically used for sonic anemometer data, Auxiliary Inputs: this is described in detail in Configuring the Analog Anem- ometer Inputs on page 3-27. Specifies whether the temperature Temperature Source: source is the instrument, a temperature sensor on Auxiliary Input 1, or a User Entered value.
  • Page 135 Section 7. Software Reference Pressure is measured at both the LI-7200RS sensor head, and in the LI- Note: 7550 Analyzer Interface Unit. The LI-7200RS sensor head pressure is displayed as the differential between the head and the box (LI-7550). The Total Pressure is the box pressure plus the head pressure.

  • Page 136: Outputs

    Section 7. Software Reference Outputs window allows you to configure the analog output channels, RS-232, Outputs Ethernet, or Synchronous Device for Measurement (SDM) outputs. tab presents settings that affect all outputs Setup Delay Time Bandwidth (RS-232, Ethernet, DACs, and SDM). Bandwidth (5, 10 or 20 Hz) determines the signal averaging done by the digital filter.
  • Page 137 Section 7. Software Reference RS-232 Output The RS-232 tab is used to set the instrument's RS-232 port configuration for unat- tended data collection. After configuration, click Apply The instrument will begin to send data out the RS-232 port according to these para- meters after you disconnect from the instrument (or immediately if you are con-...
  • Page 138 Section 7. Software Reference Under , you can choose whether or not to output labels with each data Options record, and whether to output diagnostic text records. An example of a data record sent with and without labels is shown below. Data format with labels: (Data (Ndx 87665) (DiagVal 757) (Date 2009-09-10) (Time 14:06:44:140) CO2Raw 0.0332911) (H2ORaw 0.19299) (CO2D...
  • Page 139 Section 7. Software Reference Under Data Output, select the data records that you want to output; click Select All to choose all, or to disable all checked values. The data items available Select None for display given in Table 3-1 on page 3-14. DAC Configuration The LI-7550 has the capability to output up to 6 variables on DAC channels 1-6.
  • Page 140 Section 7. Software Reference logger, the white wire (SDM_CLK) to C2, the brown wire (SDM_EN) to C3 and the black wire (ground) to ground. SDM communications are enabled in Campbell Scientific®, Inc. dataloggers with the LI7200 instruction. This instruction is only available in dataloggers pro- grammed in CRBasic (e.g.
  • Page 141 Section 7. Software Reference Table 7-1. Parameter 4 value definitions. (...continued) Mode Items Sent dry (µmol/mol) O dry (mmol/mol) (mmol/m O (mmol/m Signal Strength (average) Head Pressure (kPa) (°C) (°C) Aux channel #1 Aux channel #2 Aux channel #3 Aux channel #4 (mmol/m O (mmol/m absorptance...
  • Page 142 Section 7. Software Reference Delay Time The output signal from the optical bench is sampled by a high-speed analog-to- digital converter and input into a digital signal processor (DSP). This signal is pro- cessed digitally and gas densities are computed from it. There is a fixed delay in this process, and an additional user-programmable delay that can be used to make the instrument output occur on even sampling intervals.
  • Page 143 Section 7. Software Reference Bandwidth is the frequency at which the indicated amplitude is 0.707 of the real amplitude (Figure 7-1 below). Figure 7-1. Bandwidth = 1/oscillation period. Bandwidth is a useful indicator for characterizing real-world behavior in which there are fluctuating gas concentrations. Given a sinusoidal oscillation of con- centration, the instrument's ability to measure the full oscillation amplitude dimin- ishes as the oscillation frequency increases.
  • Page 144 Section 7. Software Reference Diagnostic Value The cell diagnostic value is a 2 byte unsigned integer (value between 0 and 8191) with the following bit map: bit 15 bit 14 bit 13 bit 12 bit 11 bit 10 bit 9 bit 8 Aux_ Unused...

  • Page 145: Calibration Overview

    Section 7. Software Reference Calibration Overview The LI-7200RS uses a fifth order poly- nomial for the CO calibration, and a third order polynomial for the H O cal- ibration. Step-by-step instructions for calibrating the gas analyzer can be found in Calibration on page 4-1.
  • Page 146 The calibration coefficients are stored in the LI-7550 Analyzer Interface Unit, not the sensor head. To change these values, edit them and then click Apply to send these values to the LI-7200 for implementation. Caution: To avoid undesirable changes to the instrument performance, do not edit values in this window.
  • Page 147 Section 7. Software Reference The Head Serial Number displays the serial number of the sensor head that is asso- ciated with the coefficients. When exchanging sensor heads, it is necessary to change calibration coefficients, and to redo the zero and span. Note: The easiest way to get the calibration coefficients, zero, and span updated for a sensor head is to save the configuration (it is a *.7x file) and then upload the file to a different LI-7550 using...

  • Page 148: Changing Sensor Heads

    Enter the calibration coefficients from the Calibration Certificate under the Coefficients tab. Zero and span the instrument. Automatic Acquire a calibration file for your instrument. You can get it from the LI-COR sup- port site (www.licor.com/env/support) under calibration information, or you can save it from the LI-7550 ( ).

  • Page 149: Diagnostic Messages

    Service Head – Displays the model of the sensor head currently connected to the LI-7550 Analyzer Interface Unit. The software may display LI-7200 even if an LI-7200RS is connected and LI-7500A even though an LI-7500RS is connected. Avg. Signal Strength – Average Signal Strength is a coarse indicator of when to clean the instrument, where 100 is clean, 80 is relatively dirty, 50 is very dirty, and 0 would mean no signal at all.

  • Page 150: Test Point Values

    Test Point Values tab displays voltages and raw counts of a variety of diagnostic test Test Points points. Though primarily for LI-COR technician reference, values outside of the normal range may give you an indication of where problems may be originating. 7-18...
  • Page 151 Section 7. Software Reference Test Point Description Normal range IR A/D (V) Voltage from IRGA being sent to 0.2 – 4.8 V A/D converter Detector Temp (V) Detector temperature voltage 2.9 V. Readings near +5 V or 0 V are normal for a few seconds after power Aux Ref + 16-bit conversion of positive...

  • Page 152: Waveform

    Waveform tab displays the current Waveform state of the analyzer’s chopping shutter disk. Though primarily for LI-COR tech- nician reference, if problems are encountered, it may be useful to log the waveform data for troubleshooting pur- poses. Waveform data can only be logged when the window is open.

  • Page 153: Charting

    Section 7. Software Reference Charting page allows real time graphics display of one or two variables plot- Strip Chart ted against time. The Y-Axes (left and right) display the value chosen in the respect- ive menus against time on the X-Axis. Time on the X-Axis can be displayed over user-defined values of seconds or...
  • Page 154 Section 7. Software Reference You can rescale both Y-axes of an active strip chart by right clicking on the Note: chart, holding, and dragging up or down. You can also open as many chart win- dows as you want. 7-22 LI-7200RS Enclosed CO O Analyzer...

  • Page 155: Pc Logging

    Section 7. Software Reference PC Logging The PC Logging window is used to configure the data out- put parameters used while the LI-7500RS or LI-7200RS Win- dows software is active. Data are logged to a file on your computer. You can specify the destination file, update rate, file duration, comments, and values to be logged.

  • Page 156: Configuration Files

    Section 7. Software Reference Configuration Files The PC software uses a configuration file to store parameters of the instrument con- figuration. These configuration files include information such as auxiliary input cal- ibration coefficients, DAC output channels, instrument calibration coefficients and zero and span values, and the source channels that you want to log.
  • Page 157 Diagnostics tab at the top of the GHG Windows Interface soft- ware. You can view the latest version numbers and acquire the software from the LI-COR web site: www.licor.com/env/support. On the support web site, select your instrument, then select "Software." Download...
  • Page 158 Section 7. Software Reference Click and select the instrument from the list. You may need to allow the application to Browse... pass through your computer's firewall. Select the gas analyzer from the list and click Update Software The update will take about 5 minutes. Important: Do not close the software, let your PC go to sleep, or power off the instru- ment during the update process.
  • Page 159 Section 7. Software Reference Troubleshooting: Getting an update error? There must be a USB drive installed in the LI-7550 USB port before you can update. Also, if the drive is inserted for the first time, the instrument will take a few minutes to connect with the drive. Windows Software Update To update the Windows interface software for gas analyzers: The GHG Windows interface software is an executable file named something similar to...
  • Page 160 Section 7. Software Reference 7-28 LI-7200RS Enclosed CO O Analyzer...

  • Page 161: Section 8. Theory Of Operation

    Section 8. Theory of Operation Relating Absorption to Concentration The scaling law of Jaimeson et. al., (1963) shows the effect of pressure on infrared absorption. If the amount of absorber of some gas u (mol m ) and absorption in a band are related by some function h (), then The subscript i denotes a particular (i...

  • Page 162: Measuring Absorptance

    Section 8. Theory of Operation “known densities”, the ρ values are computed from known concentrations m (moles of gas per mole of air) using the ideal gas law Measuring Absorptance Given a source with radiant power Φ, and a detector some distance away, in the absence of reflection, absorptance by gas i can be determined from where is transmittance through gas i,...

  • Page 163: Cross Sensitivity

    Section 8. Theory of Operation Cross Sensitivity Because the instrument uses one detector for measuring A , and A , (the absorbed and non-absorbed power for CO and H O, respectively), there is a slight cross-sensitivity between gases due to imperfections in the detector's frequency (time) response.

  • Page 164: Equation Summary

    Section 8. Theory of Operation Equation Summary In the atmosphere, the absorption of radiation by water vapor is not significantly influenced by any other gas, so the effective pressure for water vapor P is simply the total pressure P. 8-12 O absorptance, α...
  • Page 165 Section 8. Theory of Operation accounted for in the equivalent pressure of P . A method of doing this (LI-COR Application Note #116) is 8-16 P is pressure, α is the band broadening coefficient, and m is the mole fraction of water vapor.

  • Page 166: Li-7200Rs Implementation

    Section 8. Theory of Operation LI-7200RS Implementation Air pressure, P , (kPa) and temperature, T , (°C) are measured in the sampling cell (see A Note About Pressure And Temperature on the facing page). W is the mole frac- tion of water vapor, and Table 8-1.

  • Page 167: A Note About Pressure And Temperature

    Section 8. Theory of Operation A Note About Pressure And Temperature Since the instrument is calibrated for number density, accurate temperature is not required for the calculation, and accurate pressure measurement is not required, either (equations 8-20 and ). For example, if you introduce a 1% error in the pres- sure sensor on a perfectly calibrated instrument, the resulting CO mole density error would be about 0.25%, and the H...
  • Page 168 Section 8. Theory of Operation precipitation, etc.) in the optical path. The values of these signals by themselves is not very informative: all you are guaranteed of is that they will be somewhere between 0 and 65535, but more typically between 25000 to 50000. To get a useful diagnostic out of A and A , one needs to know the expected value for a par-...
  • Page 169 Section 8. Theory of Operation Average values of b and c are both 0.05 for the LI-7200RS, but the values for a par- ticular unit are found on its calibration sheet. Figure 8-1 below illustrates this func- tion by showing the range of responses for a large population of LI-7200s. Figure 8-1.

  • Page 170: Delta Signal Strength

    Section 8. Theory of Operation Two signal strength-based values are available from the LI-7200RS when using the Windows interface program. 8-37 8-38 The instrument’s grammar also makes the individual values (S and S ) available for output. Delta Signal Strength Why Delta Signal Strength? The concern when checking a source strength dia- gnostic is “Is the optical cell clean?”...
  • Page 171 Section 8. Theory of Operation Note: these assume contamination with a linear spectral response. As a practical matter, you should experiment at your installation to see if there is a consistent rela- tion between Delta Signal Strength and calibration shift. LI-7200RS Transfer Functions and Signal Processing Signal Processing Bandwidth/Frequency Response...
  • Page 172 Section 8. Theory of Operation 8-12 LI-7200RS Enclosed CO O Analyzer...

  • Page 173: Specifications

    Appendix A. Specifications Measurements Calibration Range: 0 to 3000 µmol mol Accuracy: Within 1% of reading Zero Drift (per °C): ±0.1 ppm typical; ±0.3 ppm maximum RMS Noise (typical @ 370 ppm CO @5 Hz: 0.08 ppm @10 Hz: 0.11 ppm @20 Hz: 0.16 ppm Gain Drift (% of reading per °C @ 370 ppm): ±0.02% typical;...
  • Page 174 Appendix A. Specifications General Fundamental Gas Sampling Rate: 150 Hz Bandwidth: 5, 10, or 20 Hz; software selectable Type: Absolute, non-dispersive infrared gas analyzer Detector: Thermoelectrically cooled lead selenide Path Length: 12.5 cm (4.72") Optical Cell Volume: 16 cm Optical Cell Thermocouples (Input and Output): Max.
  • Page 175 Appendix A. Specifications Gas Analyzer Dimensions Appendix A. Specifications...
  • Page 176 Appendix A. Specifications LI-7550 Dimensions Insulated Intake Tube Specifications 0.25" (6.35 mm) Outside Diameter: 0.21" (5.334 mm) Inside Diameter: 0.020" (0.51 mm) Wall Thickness: 40" (101.6 cm) Length: 102 cm Intake tube path length when assembled: 106.5 cm Intake tube path length with Swagelok® filter: LI-7200RS Enclosed CO O Analyzer...
  • Page 177 Appendix A. Specifications 304 Stainless Steel Material: Figure A-1. Dimensions for the intake tube and cap (A) and the intake filter assembly (B). Appendix A. Specifications...
  • Page 178 Appendix A. Specifications Heated Intake Tube Specifications 10.5 - 30 V Input Voltage: 0.1 W to 6 W (Heat density ratio: 2:1 short tube to long Total Output Wattage: tube) -40 °C to 50 °C Operating Temperature Range: RS-485 Data Communication Protocol: 5.33 mm (0.21”) Intake Tube Inside Diameter: 6.35 mm (0.25”)
  • Page 179 Appendix B. Pin Assignments LI-7550 Pin Assignments AUXILIARY INPUT DAC OUTPUT PIN 1 BROWN SDM_EN PIN 1 WHITE AUX1+ PIN 1 WHITE DAC1 PIN 2 WHITE SDM_CLK PIN 2 BROWN AUX1- PIN 2 BROWN DAC2 PIN 3 BLUE SDM_DATA PIN 3 GREEN AUX2+ PIN 3...
  • Page 180 Appendix B. Pin Assignments LI-7200RS Enclosed CO O Analyzer...
  • Page 181 The company names, addresses, and phone numbers are the most current we have at the time of this printing. In some cases the information may change without notice. Chemical Sources Material LI-COR Part Number Ascarite II, 500 g 9970-022 Magnesium Perchlorate, 2 kg 9960-078...
  • Page 182 7130 Engineer Rd San Diego, CA 92111 Phone: 858-279-7400 www.ocp.com LI-COR Part Cable Cable Connector OCP Part Number Number 392-13984 19-pin head 19-pin male to Specify LI-COR 392-13984 cable female and the length you prefer LI-7200RS Enclosed CO O Analyzer...
  • Page 183 16 GB industrial grade drives are available directly from LI-COR. Contact us for more information. NOTE: The USB flash drive listed below has been tested by LI-COR; if you want to use other drives in the LI-7550, please contact LI-COR for more information.
  • Page 184 Appendix C. Suppliers LI-7200RS Enclosed CO O Analyzer...
  • Page 185 Appendix D. Configuration Grammar Note: This grammar supports the core features of the instrument, but some func- tions are not fully described. Contact us if you have questions. This section describes the protocol used by the instrument to communicate via RS- 232 and Ethernet, for both configuration and data output purposes.

  • Page 186: Command Summary

    Appendix D. Configuration Grammar commands, while is not. (Freq..) (RS232..) (BW..) (BW..) (RS232..) are both commands, however, and the “extra” parenthesis at the end (Outputs..) signals the end of the command. (BW 5)) (Outputs..) An illegal command string would be (BW 5) because the command is only recognized within the context of an...
  • Page 187 Appendix D. Configuration Grammar you!" { item1 | item2 | item3 } means you must include one of the items in the list. {bool} - { TRUE | FALSE } The (Outputs..) Command is used to configure the items pertaining to data output, including (Outputs..) the bandwidth, delay time, DACs (digital to analog convertors), the RS-232 port, Ethernet and USB Logging.
  • Page 188 Appendix D. Configuration Grammar Command Subcommands Remarks (Outputs (RS232 (Baud {9600 | 19200 | 38400}) Baud rate for RS-232 (Freq {float}) Output frequency of (Data..) records in Hz. Usable values: 0.0 thru 20.0 (Labels {bool}) (DiagRec {bool}) (EOL {"hex code(s)"}) User defined termination character(s) for data record in "hex"...
  • Page 189 Appendix D. Configuration Grammar Command Subcommands (Metadata (Log {bool}) (Site (site_name {string}) (altitude {float}) (gpsformat {DDD MM SS.SSS | DDD MM.MMM | Decimal Degrees}) (latitude {+|- xxxd xx' xx.xxx"} | {+|- xxxd xx.xxx'} | {+|- xxx.xxxx} (longitude {+|- xxxd xx' xx.xxx"} | {+|- xxxd xx.xxx'} | {+|- xxx.xxxx} (canopy_height {float})
  • Page 190 Appendix D. Configuration Grammar (EOL "{hex code(s)"}) End of Line character. Enter hex value in double quotes. Example: (Outputs(RS232(EOL "0D0A”)))lf would terminate data strings with a carriage return and a line feed. (Ndx {bool}) Determines whether an index value is transmitted or not. Example: (Outputs(RS232(Ndx TRUE)))lf would cause the data stream to contain an index value.
  • Page 191 Appendix D. Configuration Grammar NOTE: The (DiagRec and the (DiagVal are two separate outputs and are inde- pendent of one another. (Labels {bool}) This command controls whether or not data labels are transmitted with the data stream. Default is TRUE, and this means that data are transmitted in the normal (Data) format record.
  • Page 192 Appendix D. Configuration Grammar 765 250 0.15402 32.2342 0.03579 196.995 24.49 98.6 0 1.5703 1033 250 0.15400 32.2097 0.03571 196.771 24.63 98.5 0 1.5724 1288 250 0.15405 32.2341 0.03578 196.838 24.76 98.5 0 1.5734 1544 250 0.15406 32.2385 0.03575 196.782 24.72 98.5 0 1.5724 Examples: To set the instrument to output only CO and H...
  • Page 193 Appendix D. Configuration Grammar Table D-2. Data and Diagnostic Records Record Subcommands Remarks (Data (Ndx {int}) Index value. Increments by 150 The values included are set every second. by (Outputs(...)). How often this is output is determined (Time {}) Time by (Outputs (Freq...)).
  • Page 194 Appendix D. Configuration Grammar Table D-2. Data and Diagnostic Records (...continued) Record Subcommands Remarks (Data (CO2AW {float}) Source The values included are set by (Outputs(...)). How often (CO2AWO {float}) Reference this is output is determined (CO2Raw {float}) absorptance by (Outputs (Freq...)). (CO2D {float}) density (mmol m (CO2MF {float})
  • Page 195 Appendix D. Configuration Grammar Record Subcommands Remarks (Diagnostics (Path {float}) Average Signal Strength (0-100) Diagnostics are always output at 1 Hz (Synch Synch (always true) {bool}) (PLL {bool}) Phase lock loop status (DetOK Detector temperature control {bool}) (Chopper Chopper temperature control {bool}) (PDif {bool}) Differential pressure...
  • Page 196 Appendix D. Configuration Grammar Examples: A typical (Data..) output record, with all items present, is shown below: (Data (Ndx 215713)(CO2Raw 1.2831902e-1)(CO2D 2.2083146e1)(H2ORaw 5.5372476e-2)(H2OD 3.5485935e2)(Temp 2.5886261e1)(Pres 9.8157062e1)(Aux 0)(Cooler 1.0537354)) A typical (Diagnostics..) record is shown below: (Diagnostics (Sync TRUE)(PLL TRUE)(DetOK TRUE)(Chopper TRUE)(Path 63)) Data Polling (Software and Hardware) A software command using the ENQ character (0x05) is available to query the...
  • Page 197 Data are updated to RS-232 at 20 Hz. If the CTS line is toggled, record will be out- put the next time one is ready. The CTS line is pin 7 on the LI-COR RS-232 Cable, part number 392-10268. The RS-232 serial pin-out from a DB9 connector on an AT...
  • Page 198 Appendix D. Configuration Grammar The (Inputs..) Command The (Inputs..) command is used to scale the Auxiliary input channel, and to determ- ine how pressure and temperature are measured by the instrument. Table D-3. The Inputs Command. Command Subcommands Remarks (Inputs (Pressure (Source { Aux | Measured | How it is determined...
  • Page 199 Appendix D. Configuration Grammar The (Calibrate...) and (Coeffs...) Commands commands control zeroing, spanning, and (Calibrate..) (Coeffs..) factory calibration coefficients. The subcommand must be present, and (Date (Val must be absent to perform . For (ZeroH2O (ZeroCO2 (SpanCO2 (SpanH2O must be present, and must be absent to trigger a cal- (Date (TDensity...
  • Page 200 Appendix D. Configuration Grammar Command Subcommands Remark (Coeffs (Current (SerialNo {quoted string}) The 72H-xxxx head number. (Band (A {float})) The band broadening coefficient (1.15). (CO2 (A {float}) These values are found on the calibration sheet. SD1, (B {float}) SD2, and SD3 are b1, b2, (C {float}) and b3 from equation 8-17.
  • Page 201 Appendix D. Configuration Grammar If the temperature is 23°C, and the pressure 98kPa, then the mode density is 15.92 mmol CO . Then send the following: (Calibrate(SpanCO2(Target 400)(Tdensity 15.92)(Date "14 Sept 2015"))) The Program Reset Command is the equivalent of pressing the reset button on the main (Program(Reset TRUE)) board.
  • Page 202 Appendix D. Configuration Grammar Flow Module Command Table D-7. Flow Module Commands Remarks Record Subcommands Communication address of Flow (BusAddress {int}) Module (32 to 255) 0: Flow On, 1: Flow Off (State {0|1} Set flow module output, SLPM (SetFlowRate {float}) Read Only –...
  • Page 203 Appendix D. Configuration Grammar The Query Command The Query (?) command is used to query the instrument for any configuration para- meter individually, as well as any node in the configuration tree. Table D-8. Query Commands Command Remarks (Outputs ?) The query for individual parameters works only for (Calibrate ?) configuration parameters and not data or diagnostic...
  • Page 204 Appendix D. Configuration Grammar Example Response: (Coef (Current (SerialNo 75H-Beta6)(Band (A 1.15))(CO2 (A 1.56704E+2)(B 2.15457E+4)(C 4.33894E+7)(D -1.24699E+10)(E 1.75102E+12)(XS 0.0023)(Z 0.0002))(H2O (A 5.24232E+3)(B 3.91896E+6)(C -2.33026E+8)(XS -0.0009)(Z 0.0185))(Pressure (A0 56.129)(A1 15.250))(DPressure (A0 1.0)(A1 0.0)))) (Outputs ?)lf causes a Outputs record to be put in the output queue. Example Response: (Outputs (BW 10)(Delay 0)(SDM (Address 7))(Dac1 (Source NONE) (Zero -5e-2)(Full 4e-1))(Dac2 (Source PRESSURE)(Zero -1e-1)
  • Page 205 Appendix D. Configuration Grammar Example Response: (Data (Ndx 2471)(DiagVal 250)(CO2Raw 1.6319131e-1)(CO2D 3.5119712e1)(H2ORaw 3.1672954e-2)(H2OD 1.7067077e2)(Temp 2.3874512e1)(Pres 9.8735609e1)(Aux 0)(Cooler 1.5630015)) (Diagnostics ?)lf causes a Diagnostics record to be put in the output queue. Example Response: (Diagnostics (SYNC TRUE)(PLL TRUE)(DetOK TRUE)(Chopper TRUE)(Path 65)) (EmbeddedSW ?)lf causes an EmbeddedSW record to be put in the output queue.
  • Page 206 Appendix D. Configuration Grammar The Connection Protocol The purpose of this section is to describe the protocol used to establish com- munications with the instrument when it is operating in an “unknown” mode. That is, when the baud rate is not known, nor are any other details about the instru- ment’s configuration.
  • Page 207 Inc.'s examination discloses to have been defective in material or workmanship without charge and only under the following conditions, which are: The defects are called to the attention of LI-COR, Inc. in Lincoln, Nebraska, in writing within one year after the shipping date of the instrument.
  • Page 208 LI-COR, Inc. or its representatives be liable for dam- ages beyond the price paid for the instrument, or for direct, incidental or consequential damages.
  • Page 209 Appendix F. Index Cell Pressure, 8-7 Cell Temperature, 8-7 Ascarite II, 5-5 Charts, 7-21 Auxiliary Inputs Cleaning configuring, 7-2 optics, 5-2 Auxiliary Sensor Interface, 2-19 Commands, D-2, D-8 about connections, 2-21 biomet sensors, D-21, D-21 connecting sensors, 2-21 flow module, D-18 mounting, 2-19 Configuration Files, 7-24 terminals, 2-20...
  • Page 210 Appendix F. Index Dirt cleaning the optics, 5-2 clock, 3-21 DSP, 8-11 format, 3-24 Dust Filter, 2-9, 2-10 Grammer, D-1 Cleaning, 5-11 Graphs, 7-21 Important Note, 2-10 Heads Eastward Separation, 3-33, 3-38 interchanging, 7-16 Eddy Covariance Humidity CH4 Log Values, 3-39 operating in humid areas, 2-16 checklist, 3-18 CO2/H2O Log Values, 3-31, 3-33...
  • Page 211 Appendix F. Index Soda Lime, 5-5 Software Update Optical Bench GHG, 7-24 disassembly, 5-3 LI-7200RS, 7-24 Output LI-7500RS, 7-24 DAC, 7-7 Sonic Anemometer Ethernet, 7-6 inputs, 3-27 rates, 7-5 Sonic Anemometer Information, 3-25 RS-232 Serial, 7-5 Span about, 4-3 command, D-15 Part Numbers, 1-2 secondary, 4-8 Planar Fit, 3-57...
  • Page 212 Appendix F. Index XML, D-1, D-2, D-8 example commands, D-15 Zero checking, 4-2 command, D-15 stability, 4-1 LI-7200RS Enclosed CO O Analyzer...
  • Page 214 Germany Phone: +49 (0) 6172 17 17 771 Fax: +49 (0) 6172 17 17 799 envsales-gmbh@licor.com envsupport-gmbh@licor.com LI-COR Ltd., United Kingdom Serving Denmark, Finland, Ireland, Norway, Sweden, and UK. LI-COR Biosciences UK Ltd. St. John’s Innovation Centre Cowley Road Cambridge...

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