CPEC310

Expandable Closed Path Eddy Covariance System w/EC155, Pump Module, & 3-Valve Module (-30 to +50C)**

The CPEC310 with EasyFlux™ is a turn-key, closed-path eddy-covariance (EC) flux system for long-term monitoring of atmospheric-biosphere exchanges of carbon dioxide, water vapor, heat, and momentum. A complete system consists of a closed-path gas analyzer (EC155 closed-path gas analyzer), sonic anemometer (CSAT3A sonic anemometer), data logger (CR6 datalogger), sample pump, three-valve module that enables automatic zero and CO₂ span measurements (manual H₂O span), and accommodations for a Granite™ Volt 116 analog input expansion module allowing for additional sensors.

The gas analyzer’s patented vortex intake design (United States Patent No. 9,217,692) and small sample cell volume (5.9 mL) provide a much lower flow rate than other closed-path systems while maintaining excellent frequency response (4.3 Hz cutoff frequency). Additionally, this design makes the system virtually maintenance free while still maintaining an ideal frequency response compared to traditional inline filters. Lower flow allows the CPEC310 to have one of the lowest total system power requirements (12 W) of any closed-path eddy covariance system. Campbell Scientific manufactures all components of the CPEC310, including the data logger and EasyFlux DL software for computing and correcting fluxes, which gives our system the most reliable functionality.

Fully Expandable Design
Provides additional ports with automatic zero and span

The gas analyzer’s small sample cell volume (5.9 mL) minimizes the sample residence time (50 ms at the system’s nominal flow rate, 7 LPM). This gives excellent frequency response (5.8 Hz half-power bandwidth) with low total system power (12 W).

Eddy-Covariance Measurements

CO₂ and H₂O are measured with an EC155 Closed-Path Gas Analyzer. Three-dimensional wind speed and sonic air temperature are measured with a CSAT3A sonic anemometer head.

CPEC310 System Enclosure

The CPEC310 has two enclosures: a fiberglass enclosure that houses the CR6 datalogger, pump module, three-valve module, and optional Granite Volt 116 , and the EC100 enclosure for data processing. The CPEC310 can also be equipped with a scrub module for automatic zeroing of the EC155.

CPEC310 Pump Module

The pump module, a standard component of the CPEC310 system, consists of a small dual-head diaphragm pump with a brushless dc motor mounted inside a fiberglass enclosure. An integral cable connects the pump module to the CPEC310 system enclosure, which provides power, temperature measurement and control, pressure measurement, and pumping speed measurement and control.