Campbell Scientific - Model IRGASON - Integrated CO2 and H2O Open-Path Gas Analyzer and 3-D Sonic Anemometer
From Heat, Water Vapor, and Carbon Dioxide Flux Sensors
Campbell Scientific’s IRGASON fully integrates the open-path analyzer and sonic anemometer. Designed specifically for eddy-covariance carbon and water flux measurements, the patented design is easier to install and use than separate sensors and provides increased measurement accuracy. The IRGASON simultaneously measures absolute carbon dioxide and water vapor, air temperature, barometric pressure, three-dimensional wind speed, and sonic air temperature. U.S. patent D680455.
Detailed Description
The IRGASON has the following outputs:
- Ux (m/s)
- Uy (m/s)
- Uz (m/s)
- Sonic Temperature (°C)
- Sonic Diagnostic
- CO2 Density (mg/m3)
- H2O Density (g/m3)
- Gas Analyzer Diagnostic
- Ambient Temperature (°C)
- Atmospheric Pressure (kPa)
- CO2 Signal Strength
- H2O Signal Strength
- Source Temperature (°C)
Benefits and Features
- New conformal coating helps protect sonic transducers in corrosive environments
- Combined support structure causes less flow distortion than two separate sensors
- Truly colocated gas analyzer and sonic anemometer measurements avoid flux loss due to sensor separation
- Synchronized gas analyzer and sonic anemometer measurements avoid the need to correct for time lag
- Low power consumption; suitable for solar power applications
- Measurements are temperature compensated without active heat control
- Low noise
- Maximum output rate of 60 Hz with 20 Hz bandwidth
- Angled windows shed water and are tolerant to window contamination
- Field rugged
- Field serviceable
- Factory calibrated over wide range of CO2, H2O, pressure, and temperature in all combinations encountered in practice
- Extensive set of diagnostic parameters
- Fully compatible with Campbell Scientific dataloggers; field setup, configuration, and field zero and span can be accomplished directly from the datalogger
- Sonic temperature determined from three acoustic paths; corrected for crosswind effects
- Innovative signal processing and transducer wicks considerably improve performance of the anemometer during precipitation events
Specifications
- Patent: U.S. Patent No. D680455
- Operating Temperature Range: -30° to +50°C
- Calibrated Pressure Range: 70 to 106 kPa
- Input Voltage Range: 10 to 16 Vdc
- Power: 5 W (steady state and power up) at 25°C
- Measurement Rate: 60 Hz
- Output Bandwidth: 5, 10, 12.5, or 20 Hz (user-programmable)
- Output Options: SDM, RS-485, USB, analog (CO2 and H2O only)
- Auxiliary Inputs: Air temperature and pressure
- Warranty: 3 years or 17,500 hours of operation (whichever comes first)
- Cable Length: 3 m (10 ft) from IRGASON to EC100
- Weight:
- 3.2 kg (7.1 lb) for EC100 electronics
- 2.8 kg (6.1 lb) for IRGASON head and cables
- Gas Analyzer
- Path Length: 15.37 cm (6.05 in.)
- A temperature of 20°C and pressure of 101.325 kPa was used to convert mass density to concentration.
Gas Analyzer - CO2 Performance
- NOTE-: A temperature of 20°C and pressure of 101.325 kPa was used to convert mass density to concentration.
- Accuracy:
- Assumes the following: the gas analyzer was properly zero and spanned using the appropriate standards; CO2 span concentration was 400 ppm; H2O span dewpoint was at 12°C (16.7 ppt); zero/span temperature was 25°C; zero/span pressure was 84 kPa; subsequent measurements made at or near the span concentration; temperature is not more than ±6°C from the zero/span temperature; and ambient temperature is within the gas analyzer operating temperature range.
- 1% (standard deviation of calibration residuals)
- Precision RMS (maximum): 0.2 mg/m3 (0.15 μmol/mol)
- Nominal conditions for precision verification test: 25°C, 86 kPa, 400 μmol/mol CO2, 12°C dewpoint, and 20 Hz bandwidth.
- Calibrated Range: 0 to 1,000 μmol/mol (0 to 3,000 μmol/mol available upon request.)
- Zero Drift with Temperature (maximum): ±0.55 mg/m3/°C (±0.3 μmol/mol/°C)
- Gain Drift with Temperature (maximum): ±0.1% of reading/°C
- Cross Sensitivity (maximum): ±1.1 x 10-4 mol CO2/mol H2O
Gas Analyzer - H2O Performance
- NOTE-: A temperature of 20°C and pressure of 101.325 kPa was used to convert mass density to concentration.
- Accuracy:
- Assumes the following: the gas analyzer was properly zero and spanned using the appropriate standards; CO2 span concentration was 400 ppm; H2O span dewpoint was at 12°C (16.7 ppt); zero/span temperature was 25°C; zero/span pressure was 84 kPa; subsequent measurements made at or near the span concentration; temperature is not more than ±6°C from the zero/span temperature; and ambient temperature is within the gas analyzer operating temperature range.
- 2% (standard deviation of calibration residuals)
- Precision RMS (maximum): 0.004 g/m3 (0.006 mmol/mol)
- Nominal conditions for precision verification test: 25°C, 86 kPa, 400 μmol/mol CO2, 12°C dewpoint, and 20 Hz bandwidth.
- Calibrated Range: 0 to 72 mmol/mol (38°C dewpoint)
- Zero Drift with Temperature (maximum): ±0.037 g/m3/°C (±0.05 mmol/mol/°C)
- Gain Drift with Temperature (maximum): ±0.3% of reading/°C
- Cross Sensitivity (maximum): ±0.1 mol H2O/mol CO2
Sonic Anemometer - Accuracy
- -NOTE-: The accuracy specification for the sonic anemometer is for wind speeds < 30 m s-1 and wind angles between ±170°.
- Offset Error:
- < ±8.0 cm s-1 (for ux, uy)
- < ±4.0 cm s-1 (for uz)
- ±0.7° while horizontal wind at 1 m s-1 (for wind direction)
- Gain Error:
- < ±2% of reading (for wind vector within ±5° of horizontal)
- < ±3% of reading (for wind vector within ±10° of horizontal)
- < ±6% of reading (for wind vector within ±20° of horizontal)
- Measurement Precision RMS:
- 1 mm s-1 (for ux, uy)
- 0.5 mm s-1 (for uz)
- 0.025°C (for sonic temperature)
- 0.6° (for wind direction)
- Speed of Sound: Determined from 3 acoustic paths (corrected for crosswind effects)
- Rain: Innovative signal processing and transducer wicks considerably improve performance of the anemometer during precipitation events.
Basic Barometer (option -BB)
- Total Accuracy:
- ±3.7 kPa at -30°C, falling linearly to ±1.5 kPa at 0°C (-30° to 0°C)
- ±1.5 kPa (0° to 50°C)
- Measurement Rate: 10 Hz
Enhanced Barometer (option -EB)
- Manufacturer: Vaisala PTB110
- Total Accuracy: ±0.15 kPa (-30° to +50°C)
- Measurement Rate: 1 Hz
Ambient Temperature
- Manufacturer: BetaTherm 100K6A1IA
- Total Accuracy: ±0.15°C (-30° to +50°C)