Eddy Covariance carbon flux intelligent measurement system

LI-7500DS
Open Path CO₂/H₂O Analyzer

   The new LI-7500DS analyzer delivers the performance and dependability of previous LI-7500 models, in a streamlined, lower cost configuration with even lower power requirements

The LI-7500DS is designed for high-speed CO₂ and water vapor measurements in ambient air. Lower power and maintenance requirements make it ideal for field deployments.

Requiring only 4 watts during normal operation, the LI-7500DS features lower power demands than any other EC gas analyzer available. It is ideal for deployment in remote areas where power is limited.

Omnidirectional sampling provides versatile installation options and continuous data coverage.

Logs complete eddy covariance data sets—including wind speed measurements from a sonic anemometer and supporting meteorological, radiation, and soil data from a LI-COR Biomet System.

How it works

The LI-7500DS uses non-dispersive infrared spectroscopy to measure CO2 and water vapor densities in air.

Infrared radiation is transmitted through temperature controlled optical filters, then through the open sample path to a thermally regulated lead selenide detector. Some of the infrared radiation is absorbed by CO2 and water vapor in the sample path. Gas densities are computed from the ratio of absorbed radiation to a reference.

Specifications

CO₂ Measurements

• Calibration Range: 0 to 3000 µmol mol^-1

• Accuracy: Within 1% of reading

• Zero Drift(per °C):

• ±0.1 ppm typical

• ±0.3 ppm maximum

• RMS Noise (typical @ 370 ppm CO₂):

• @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

• ±0.1% maximum

• Direct Sensitivity to H₂O (mol CO₂ mol^-1 H₂O):

• ±2.00E-05 typical

• ±4.00E-05 maximum

H₂O Measurements

• Calibration Range: 0 to 60 mmol mol^-1

• Accuracy: Within 1% of reading

• Zero Drift (per °C):

• ±0.03 mmol mol^-1 typical

• ±0.05 mmol mol^-1 maximum

• RMS Noise (typical @ 10 mmol mol^-1 H₂O):

• @5 Hz: 0.0034 mmol mol^-1

• @10 Hz: 0.0047 mmol mol^-1

• @20 Hz: 0.0067 mmol mol^-1

• Gain Drift (% of reading per °C @ 20 mmol mol^-1):

• ±0.15% typical

• ±0.30% maximum

• Direct Sensitivity to CO₂ (mol H₂O/mol CO₂):

• ±0.02 typical

• ±0.05 maximum

General

• Fundamental Gas Sampling Rate: 150 Hz

• Bandwidth: 5, 10, or 20 Hz; software selectable

• Type: Absolute, open-path, non-dispersive spectroscopy

• Detector: Thermoelectrically cooled lead selenide

• Path Length: 12.5 cm (4.92")

• Air Temperature Thermistor: 10K ohm @ 25 °C thermistor

• Measurement Range: -40 to 70 °C

• Sensor Accuracy: ±0.25 °C from -20 to 70 °C

• Resolution: 0.003 °C @ 25 °C

• Pressure Sensor:

• Measurement Range: 20 to 110 kPa

• Sensor Accuracy: ±0.4 kPa from 50 to 110 kPa

• Resolution: 0.006 kPa

• Outputs: Ethernet

• Operating Temperature Range: -25 to 50 °C (-40 to 50 °C verification on request)

• Relative Humidity Range: 0-95% (non-condensing)

• Weatherproof Rating: Tested to IEC IP65 standard user

• Interface: Windows^® PC software

• Power Requirements: 10.5 to 30 VDC

• Steady-State Power Consumption: 4 W typical at 25 °C
  8 W max over operating range of -25 to 50 °C

• Head:

• Size: Diameter 6.5 cm, Length 30 cm

• Weight: 0.67 kg; 1.3 kg with mounting post

• Head Cable Length: 200 cm

• DSI Box:

• Size: 13.24 × 14.64 × 6.24 cm (H × W × D)

• Weight: 0.93 kg

MODEL：LI-7500DS

NAME:Dddy Covariance carbon flux intelligent measurement system

BRAND：LI-COR

MANUFACTURER：COUNTRY OF ORIGIN AND MANUFACTURERS