Built for eddy covariance, the LI-7700 Open Path CH₄ Analyzer is the only open-path methane analyzer designed for field deployment in eddy covariance systems. It delivers high-speed CH₄ measurements in ambient air with low power needs and minimal upkeep in real-world conditions.
Take 40 measurements per second even in the most demanding or remote environments.
Use ~8 W during normal operation, making it ideal for use with solar power supplies.
Reduce complexity with open-path, in-air measurements—no pumps or tubes required.
Capture accurate, precise CH₄ data using Wavelength Modulation Spectroscopy (WMS).

KEY FEATURES

Less Downtime

Heated mirrors keep optics clear in humid conditions, letting you spend less time servicing and more time collecting data.

The Complete Picture

Add a 3D sonic anemometer for wind measurements and collect meteorological, radiation, and soil data with LI-COR Biomet System sensors.

Built for Remote Sites

Conduct long-term, solar-powered deployments in hard-to-reach locations with its ~8 W (typical) power requirement.

Effortless Integration

LI-7700-based eddy covariance systems gain access to LI-COR Cloud^® and its next-generation data processing and analysis tools.

Proven Performance:

The Global Standard in Eddy Covariance

See the LI-7700 in action. Taken from a 2011 AmeriFlux poster, these figures (below) show the LI-7700's performance in real-world conditions.

View Poster

Figure 1: Frequency response. Spectral and co-spectral analysis is a powerful tool for evaluating the performance of the sonic anemometer and the gas analyzer. The normalized power spectrum of the LI-7700 follows the theoretical curve (above), indicating the LI-7700 has sufficient resolution and response time for eddy covariance flux measurements.

Figure 2: Zero-flux test. The averaged hourly flux data are from a methane eddy-covariance flux system at a zero-flux site in Nebraska. Chamber-based soil methane emission measurements over several years show no methane emissions.

Next-Gen Data Analysis

Bring your system online. Each LI-COR eddy covariance system is equipped with SmartFlux^® Core, the on-site hardware that sends data to LI-COR Cloud.

Explore

Remote access

View, share, and download data from your, or your collaborators', labs—from anywhere in the world.

Shareable data

Allow other researchers to conveniently access your data—even if they do not own a LI-COR device themselves.

Tailored data analytics

Access detailed analytics built from your device's data streams within LI-COR Cloud.

Easy configuration

Follow a straightforward, guided configuration that anyone on your team can do—no technical expertise required.

Specifications

LI-7700 Specifications

Resolution (RMS noise): 5 ppb @ 10 Hz and 2000 ppb CH₄
Measurement Range: 0 to 25 ppm @ -25 °C, 0 to 40 ppm @ 25 °C
Data Communication: Ethernet (up to 40 Hz)
Detection Method: Wavelength Modulation Spectroscopy 2f detection
Operating Pressure Range: 50 to 110 kPa
Output Bandwidth: up to 20 Hz
Operating Temperature Range: -25 to 50 °C
Power Requirements: 10.5 to 30 VDC
Power Consumption: 8 W nominal, 16 W during cleaning cycle
Dimensions:
- Sensor: 14.33 cm dia (5.64 inches), 82.8 cm height (32.6 inches)
- Optical Path: 0.5 m physical path (1.65 ft), 30 m measurement path (98.4 ft)
Weight: 5.2 kg (11.5 lbs)
User Interface: Windows®based software supports all setup, configuration, and calibration functions through Ethernet connection

7700-101 Mirror Cleaner Specifications

Pump Operating Temperature Range: -10 °C to 50 °C
Weight: 3.2 kg (7 lbs)
Dimensions: 44.5 x 32.8 x 15 cm (17.5 x 12.9 x 6 inches)
Fluid Capacity: 4 liters (1.1 U.S. Gallon)

LI-7550 Specifications

Data Storage: Removable USB Storage Device. 16 Gigabyte Provided (expandable with user supplied Industrial Grade USB Flash Drive)
Data Communication:
- Ethernet: up to 40 Hz
- Synchronous Devices for Measurement (SDM): up to 33.3 Hz
- RS-232: 57,600 baud, 20 records per second max.
- DAC: 0-5 V, 40 Hz
Bandwidth: Up to 20 Hz
Inputs: Ethernet, 4 analog inputs, differential ±5 V, 16 bit
Operating Temperature Range: -25° to 50° C
Power Requirements: 10.5 to 30 VDC
Power Consumption: 10 W nominal
Dimensions: 35 x 30 x 15 cm (13.8 x 12 x 6 inches) external dimensions
Weight: 4.4 kg (10 lbs)

Specifications subject to change without notice.

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LI-7700 Open Path CH₄ Analyzer

Fast open-path CH₄ measurements in ambient air