Page 4
(780) 454-2655. Campbell Scientific (Canada) Corp. is unable to process any returns until we receive this form. If the form is not received within three days of product receipt or is incomplete, the product will be returned to the client at the client’s expense.
Page 5
Periodically (at least yearly) check electrical ground connections. WHILE EVERY ATTEMPT IS MADE TO EMBODY THE HIGHEST DEGREE OF SAFETY IN ALL CAMPBELL SCIENTIFIC PRODUCTS, THE CLIENT ASSUMES ALL RISK FROM ANY INJURY RESULTING FROM IMPROPER INSTALLATION, USE, OR MAINTENANCE OF TRIPODS, TOWERS, OR ATTACHMENTS TO TRIPODS AND TOWERS SUCH AS SENSORS, CROSSARMS, ENCLOSURES, ANTENNAS, ETC.
Page 6
PLEASE READ FIRST About this manual Please note that this manual was originally produced by Campbell Scientific Inc. (CSI) primarily for the US market. Some spellings, weights and measures may reflect this origin. Some useful conversion factors: Area: 1 in...
Structure .................. 20 6.2.5 Install the EC150 Temperature Probe ......... 21 Wiring and Connections ..............22 6.3.1 Connecting the EC150 Gas Analyzer Head ........ 23 6.3.2 Connect the CSAT3A Sonic Head ..........23 6.3.3 Connect the EC150 Temperature Probe ........24 6.3.4...
Page 9
EC100 Diagnostics for Gas Analyzer Troubleshooting ..... 35 8.7.3 LED Status Lights ..............35 8.7.4 Diagnostic Flags ................. 37 Appendices A. EC150 Settings ............A-1 Factory Defaults ................A-1 Details ..................... A-1 A.2.1 SDM Address ................A-2 A.2.2 Bandwidth ................A-2 A.2.3 Unprompted Output ..............A-2 A.2.4 Unprompted Output Rate ............
Page 10
6-1. Three mounting bracket options for the EC150: pn 26785 is for the EC150 head only, pn 26786 is for the EC150 head with CSAT3A of serial numbers less than 2000, and pn 32065 is for the EC150 head with CSAT3A serial numbers 2000 and greater. .. 12 6-2.
Page 11
Table of Contents 8-1. Proper location of the gas analyzer top wick (left) and bottom wick (right) ..................33 8-2. Replacing the desiccant and CO scrubber bottles (replacement bottles purchased in or after July 2017 may appear different than in the figure) ................34 8-3.
O Open-Path Gas Analyzer Introduction The EC150 is an in situ, open-path, mid-infrared absorption gas analyzer that measures the absolute densities of carbon dioxide and water vapor. The EC150 was designed for open-path eddy covariance flux measurements as part of an open-path eddy covariance measurement system.
O Open-Path Gas Analyzer • WARNING: Do not carry the EC150 by the arms or the strut between the arms. Always hold it by the mounting base where the upper and lower arms connect. Handle the EC150 carefully. The optical source may be damaged by rough handling, especially while the analyzer is powered.
(p. 37) user when the instrument needs servicing and can facilitate troubleshooting in the field. The EC150 outputs the optical strength of signals, which can be used to filter data when the path of the instrument is obstructed due to precipitation...
CRBasic instructions in the datalogger. For example, in solar-powered applications with limited daylight, battery power can be conserved by programming the datalogger to turn off the EC150 at night or when conditions are not suitable for eddy-covariance measurements. The datalogger can also be used to change settings such as bandwidth, and perform the zero/span procedure in the field.
CR5000 dataloggers, the SDM protocol uses SDM-dedicated ports SDM-C1, SDM-C2, and SDM-C3. Each SDM device on the SDM bus must have a unique address. The EC150 has a factory default SDM address of 1, but may be changed to any integer value between 0 and 14 (see Appendix A.2.1, SDM Address...
= path length. In the EC150, radiation is generated by applying constant power to a tungsten lamp which acts as a 2200 K broadband radiation source. Specific wavelengths are then selected using interference filters located on a spinning chopper wheel.
Specifications Measurements To compute carbon dioxide and water vapor fluxes using the eddy-covariance method, the EC150 and a sonic anemometer measure: • Absolute carbon dioxide density (mg·m –3 •...
Page 19
EC150 CO O Open-Path Gas Analyzer Operating temperature: −30 to 50 °C Gas analyzer Measurement precision density: 0.2 mg·m –3 (0.15 µmol·mol –1 O density: 0.004 g·m –3 (0.006 mmol·mol –1 Factory calibrated range 0 to 1000 µmol·mol –1 0 to 72 mmol/mol (37 °C dewpoint) Temperature: −30 to 50 °C...
EC150 temperature sensor Manufacturer: BetaTherm Model: 100K6A1A Thermistor Accuracy: ±0.15 °C (−30 to 50 °C) Output Signals The EC100 electronics can output data from the EC150 by several means. • Campbell Scientific SDM • RS-485 • • Analog out Synchronous Device for Measurement communications protocol, or SDM, is a proprietary serial interface developed by Campbell Scientific for communication between a datalogger and a peripheral or sensor.
Installation Orientation During operation, the EC150 should be positioned vertically (±15°) so that the product label reads right side up and the upper arm (source) is directly above the lower arm (detector). If the sensor is being used with a sonic anemometer, the anemometer should be leveled and pointed into the prevailing wind to minimize flow distortion from the analyzer’s arms and other supporting...
Mounting Analyzer to Support Hardware The EC150 is supplied with mounting hardware to attach it to the end of a horizontal pipe of 3.33 cm (1.31 in) outer diameter, such as the CM202 (pn 17903), CM204 (pn 17904), or CM206 crossarm (pn 17905).
EC150 optical path to have various spatial separation from the CSAT3A sonic volume. Depending on the position, the spatial separation can range from 5.0 cm in the EC150’s most fore position to 9.7 cm in the most aft position, as illustrated in FIGURES and 6-4.
EC150 CO O Open-Path Gas Analyzer help determine the best positioning of the EC150 relative to the CSAT3A in scenarios where the measurement height is below 10 meters. FIGURE 6-2. Changes in flux attenuation ratio relative to sensor height at the most fore and aft positions...
O Open-Path Gas Analyzer pn 32065 pn 26786 FIGURE 6-3. The most forward mounting position of the EC150 relative to the CSAT3A, resulting in a 4.9 cm sensor separation. The top images show the mounting with the current CSAT3A (CSAT3A...
Page 26
O Open-Path Gas Analyzer pn 32065 pn 26786 FIGURE 6-4. The most aft (back) mounting position of the EC150 relative to the CSAT3A, resulting in a spatial separation of 9.7 cm. The top images show the mounting with the current CSAT3A...
Point the horizontal arm into the direction of the prevailing wind. Tighten all fitting set screws. WARNING Do not carry the EC150 by the arms or the strut between the arms. Always hold the sensor by the block where the upper and lower arms connect.
Retighten the bolt. CSAT3A Sonic Head EC150 Gas Analyzer Head EC150 Head Mounting Bracket (pn 32065) CM20X Crossarm CM250 Leveling Mount FIGURE 6-5. Exploded view of mounting CSAT3A and EC150 with mounting bracket 32065 (for CSAT3A with serial numbers 2000 and greater)
O Open-Path Gas Analyzer CSAT3A Sonic Head EC150 Gas Analyzer Head EC150/CSAT3A Mounting Bracket (pn 26786) CM20X Crossarm CM250 Leveling Mount FIGURE 6-6. Exploded view of mounting CSAT3A and EC150 with mounting bracket 26786 (for CSAT3A with serial numbers less than 2000)
Analyzer Head EC150 Head-Only Mounting Bracket (pn 26785) CM250 Leveling Mount FIGURE 6-7. Exploded view of mounting the EC150 without the CSAT3A using mounting bracket pn 26785 CAUTION Overtightening bolts will damage or deform mounting hardware. 6.2.3 Mounting EC150 without CSAT3A The instructions for mounting the EC150 without the CSAT3A should generally follow those in Section 6.2.2, Mounting EC150 with Optional...
EC150 CO O Open-Path Gas Analyzer CAUTION Use caution when handling the EC150 gas analyzer head. The optical source may be damaged by rough handling, especially while the EC150 is powered. NOTE The CSAT3A sonic anemometer is an updated version of the CSAT3, designed to work with the EC100 electronics.
6.2.5 Install the EC150 Temperature Probe The temperature probe should be mounted such that it measures at the same height as the sample volume of the EC150 and the CSAT3A. Attach the R.M. Young 41303-5A 6-plate solar radiation shield (pn 4020) to the mast with the included u-bolt.
EC150 CO O Open-Path Gas Analyzer FIGURE 6-10. EC150 temperature probe FIGURE 6-11. Solar radiation shield with EC150 temperature probe Wiring and Connections FIGURES 6-12 6-13 show EC100 electronics panel and the bottom of the EC100 enclosure, respectively. Refer to these figures during the wiring and connecting of the various auxiliary sensors.
EC100 enclosure labeled Cable 3. (This plug can be stored in the mesh pocket of the enclosure.) Insert the cable entry plug that is attached to the large cable of the EC150 gas analyzer head into the vacant slot.
EC100 enclosure labeled Temperature Probe (see FIGURE 6-13). Insert the three-prong temperature probe connector into the female connector on the enclosure and screw it firmly in place. The EC150 temperature probe cable is approximately 3.0 m (10.0 ft) in length.
(p. 31) Data Collection and Data Processing Data from the EC150 is collected through the EC100 and then archived onto a datalogger. A common instrument configuration is to program a datalogger to retrieve and collect raw data from the EC150, to be used for post processing,...
O Open-Path Gas Analyzer More recently, programs have been developed that efficiently record and correctly process data from instruments such as the EC150, as well as compile them with data from other, complementary instruments. Campbell Scientific has developed a program, EasyFlux™ DL, that both records and processes raw data from the EC150 to provide useful measurements immediately.
This section gives instructions for performing a zero-and-span procedure, and should be referred to any time a zero-and-span procedure is undertaken. Check and then set the EC150 zero and span according to the following steps: Remove power from the EC100/EC150. Unplugging the power cable from the EC100 is the easiest way to accomplish this.
EC150 CO O Open-Path Gas Analyzer Position the EC150 zero-and-span shroud (pn 26390) over the upper and lower snouts. See FIGURE for guidance with the following steps. Twist the two ends of the shroud together to minimize the length of the shroud.
EC150 CO O Open-Path Gas Analyzer Launch ECMon, select the appropriate USB port, and click Connect. The main screen should now be reporting real-time CO and H concentrations. 10. Click Zero/Span. A graph will appear in the lower half of the zero-and-...
Page 41
EC150 CO O Open-Path Gas Analyzer 15. Remove the CO span gas from the inlet of the shroud and replace it with O span gas from a dew-point generator or another standard reference. As water molecules can adsorb to inside of the tubing and the shroud, it may take 30 minutes or more for the H O concentration to stabilize.
Span. 24. The zero-and-span procedure is now complete. Remove the shroud, reconnect the EC150 temperature probe, and prepare the site for normal operation. Verify that readings from the instrument are reasonable. Record the zero and span coefficients for future reference and to keep track of the rate of the analyzer drift.
O Open-Path Gas Analyzer Gas Analyzer Wicks The windows of the EC150 gas analyzer are polished and slanted at an angle to prevent water from collecting on their surfaces. However, due to increased surface tension at the interface with the snout, water can pool at the edges and partially block the optical path and attenuate the signal.
Along with being a valuable troubleshooting method, a zero-and-span procedure should be performed as routine maintenance even when the EC150 is producing expected results. Campbell Scientific recommends that a zero-and-span procedure be performed at least every six months, but may be required more frequently depending on conditions.
EC150 CO O Open-Path Gas Analyzer DANGER EC150 instruments sold prior to July 2017 were sold with scrubber bottles that contained strong oxidizing agents. Avoid direct contact with the chemicals inside the bottles. Also ensure your work area is well ventilated and free of any reactive compounds, including liquid water.
Greenhouse Gases Group of the Global Monitoring Division/National Oceanographic and Atmospheric Administration in Boulder, CO, USA. The long-term calibration stability of the EC150 is achieved by the use of high quality optical and electrical components, a long lasting IR source, and a stable MCT detector.
EC150 CO O Open-Path Gas Analyzer potential problems with the measurements. During normal operation all STATUS LEDs should be green as shown in FIGURE 8-3. FIGURE 8-3. LED status during normal operation POWER Status LED • The POWER status LED will turn red if the supply voltage is outside the specified limits (see Section 5.4, Power Requirements...
Other flags are associated with the proper function of the internal components of the analyzer. If any of these flags are set, consult with Campbell Scientific for assistance in diagnosing the problem and, if necessary, arrange to send the instrument for repair.
It may occasionally be set for short periods of time (10 to 15 seconds), but if it persists, Source Power the user should consult with Campbell Scientific. Verify that ambient temperature and power supply voltage are within specifications.
Page 50
Temperature range −30 to 50 °C. If the flag is set and ambient temperature is within the specified range, consult with Campbell Scientific. Set when the infrared source current is outside the prescribed limits. It may...
Page 51
Power off the EC100 and reconnect the head. If the flag persists, Calibration Error consult with Campbell Scientific. For more information on the head memory refer to Section 4.3, Gas Head Memory (p. 3)
(p. A-9) the EC100Configure() CR Basic instruction (see Appendix A.5, EC100Configure() Instruction (p. A-9) When the EC150 is connected to a datalogger, the settings of the analyzer can be configured automatically by the CR Basic program. A.1 Factory Defaults TABLE shows the default value for each of the settings.
, for details on using SDM output. (p. 5) Each SDM device on the SDM bus must have a unique address. The EC150 has a factory default SDM address of 1, but may be changed to any integer value between 0 and 14. The value 15 is reserved as an SDM group trigger.
EC150 head. A.2.9 Fixed Temperature Value If the Temperature Sensor setting is None, the EC150 will use the value of the Fixed Temperature Value setting for the sample temperature. This mode is intended for troubleshooting only. In normal operation, the Temperature...
The Fixed Temperature Value setting is stored in non-volatile memory of the EC100 electronics. A.2.10 Pressure Sensor There are three options for measuring barometric pressure for the EC150 that have different corresponding Pressure Sensor settings. The EC100 has an on-board barometer that Campbell Scientific refers to as the EC100 basic barometer.
Appendix A. EC150 Settings FIGURE A-2. Location of EC100 enhanced barometer FIGURE A-3. Comparison of error in basic versus enhanced barometer over operational temperatures...
The Pressure Offset setting is stored in the EC100 electronics. A.2.10.3 Fixed Pressure Value If the Pressure Sensor setting is None, the EC150 will use the value of this setting for the barometric pressure. This mode is intended for troubleshooting only.
A.2.13 Head Power Off When enabled, the EC150 gas head is turned off. The head may be turn on/off under datalogger control to conserve power or under EC100 control if the gas head temperature is outside the operating range. The EC100Configure() Instructions in the CRBasic program is used to turn the gas head on/off under datalogger control.
SDM is locked, it will be held off until the instruction completes. This locking will likely result in skipped scans when reconfiguring an EC150. For the EC150 to save settings, it must go through a lengthy write- NOTE read-verify process.
Page 61
If reading a setting, 0 in the result code means that the value in the DestSource variable is the value the desired setting has in the EC150. When writing a setting, if the result code is 0, the value and setting were compatible, but the value was not changed because it contained the same value that was sent.
Page 62
ConfigCmd Variable Setting Description (some settings list possible Retrieve values for the DestSource variable) Temperature Sensor: • 0 = EC150 Temperature Probe • 1 = EC155 Sample Cell Thermistor • 2 = EC155 Sample Cell Thermocouple • 3 = None (use fixed value) •...
O, ConfigCmd 11 is set to 1. After the EC150 completes the zero, it will write the value to –1. The datalogger can poll this value or simply wait for a period of time to allow the zeroing to complete.
The EC100 measures CO and H O from the EC150 gas analyzer head. It will also measure wind velocity and sonic temperature if the optional CSAT3A sonic head is being used. EC100 measurements occur at 100z and then a user- selectable, low-pass filter is applied.
However, users should be careful to avoid attenuation of flux-carrying signals. The EC100 electronics synchronously sample the EC150 analyzer and the CSAT3A sonic head. However, users wishing to synchronize their EC100 data with other measurements (for example, a fine-wire thermocouple) in the data acquisition system must account for the time delay of the EC100 filter.
Page 66
(plus or minus one-half of the inverse of 150 Hz). Alternately, when sending data to a data acquisition system that is not manufactured by Campbell Scientific, the EC100 down-samples its USB and RS-485 outputs to a user-selectable rate of 10, 25, or 50 Hz. Although the gas...
Page 67
Appendix B. Filter Bandwidth and Time Delay...
Appendix C. Alternate EC100 Outputs C.1 USB or RS-485 Output C.1.1 Specifications Digital RS-485 Data type: ASCII Output Rate 5 to 50 Hz Baud rate 1200 to 230400 bps USB Data type: ASCII Output rate 10, 25, or 50 Hz C.1.2 Detailed Information In contrast to the SDM output mode, which is prompted by a datalogger, data can also be output from the EC100 via USB or RS485 in an unprompted mode.
Page 69
If they match, the data were received correctly If signatures do not match, the data should be disregarded. The block of code below is an example implementation of Campbell Scientific’s signature algorithm in the programming language C. To generate the signature of an output array of bytes, the seed needs to be initialized to 0xaaaa and a pointer passed to the first byte of the output array.
Appendix C. Alternate EC100 Outputs bytes in the output array should be entered in as the swath. The returned value is the computed signature. //signature(), signature algorithm. // Standard signature is initialized with a seed of 0xaaaa. // Returns signature. unsigned short signature( unsigned char* buf, int swath, unsigned short seed ) { unsigned char msb, lsb;...
Appendix C. Alternate EC100 Outputs TABLE C-2. Multipliers and Offsets for Analog Outputs Voltage Output Multiplier Density (mg·m –3 (mg·m –3 –1 Offset (mg·m –3 386.32 −102.59 8.65 −2.26...
Page 72
Appendix D. Useful Equations The following table lists all the variables and constants used in the equations below: TABLE D-1. Variables and Constants Variable or Constant Description Units ρ mass density mg·m –3 ρ O mass density g·m –3 ρ Mass density of dry air g·m –3...
Appendix D. Useful Equations Equations (D-1) and (D-2) were derived from: Leuning, R.: 2005, “Measurements of Trace Gas Fluxes in the Atmosphere Using Eddy Covariance: WPL Corrections Revisited”, Handbook of Micrometeorology, 29, 119-132. Equations (D-3), (D-4), (D-5), (D-7), (D-9), and (D-13) were derived from: Bolton, D.: 1980, “The Computation of Equivalent Potential Temperature”, Monthly Weather Review, 108, 1046-1053.
Need help?
Do you have a question about the EC150 and is the answer not in the manual?
Questions and answers