ACE

  • The ACE system is an automatic, long term, unattended, soil CO2 Flux system. Each station has its own infrared gas analyzer and each IRGA has its own auto-zero calibration capability for the most reliable measurements. Stations can be miles apart or up to 30 stations may be multiplexed for data collection and to use a single power source. Power sources include mains current, batteries, and solar solutions. Data collection may be by data card, serial port, or remote communications.

  • Measurement of CO2:

    Standard Range: 0 - 40.0 mmols/m3 or (0-896 ppm at standard temperature and pressure), 1 ppm resolution (0.05 mmols/m) noise level 1-2 ppm Infrared gas analyzer housed directly adjacent to the soil chamber.

     

    Parameters:

    Closed stations report NCER or Net CO2 Exchange Rate determined by the Pedersen (2001) algorithm. Individual assay measurements are made every ten seconds.

     

    Open stations report ΔC or Change in CO2 level in the Open design. Individual assay measurements are made every ten seconds.

     

    PAR – Photosynthetically Active Radiation.

     

    Multiple Soil temperature readouts in deg C.

     

    Multiple Soil moisture readouts as Voltages.

     

    Record number.

     

    Date.

     

    Time.

     

    Cref - Ambient CO2 concentration entering chamber.

     

    Battery power.

     

    Number of measurements in the current experiment.

     

    Maximum time limit for measurement 0- 40 minutes.

     

    ΔCset - A set point at which the CO2 level change terminates the measurement.

     

    Barometric pressure is measured and used in calculations.

     

     

    IRGA drift correction:

    Every station uses auto-zero to zero out IRGA drift before each measurement. Span drift less than 3% over 12 months.

     

    Measurement of PAR:

    0-3000 μmols /m  /sec.

     

    Measurement of Soil Temperature:

    6 selectable inputs for thermistor or thermocouple devices for different soil depths. Adapters are available for after market products.

     

    Measurement of Soil Moisture:

    4 selectable inputs for commercially available sensors. They may be purchased with the system or independently.

     

    Flow Control to Chamber:

    200 ml-5lml/min (200-3700 μmols).

     

    Flow Accuracy:

    +/- 3% of f.s.d.

     

    Display:

    240 X 64 dot matrix LCD.

     

    Programming:

    Each chamber has a user-friendly interface that is menu driven, and controlled with 5 keys.

     

    Recorded Data:

    Removable compact flash cards 1 Gigabyte storage capacity per station.

     

    Power Supply:

    External battery, solar panel, wind turbine, AC with converter. One 40Ah car battery provides power for approximately 28 days of continuous use.

     

    Output:

    1 Gigabyte Compact Flash data storage card, and RS232 port with User selectable rates of up to 19,200 BAUD (remote solutions available).

     

    Electrical Connections:

    Robust waterproof 3 pin din.

     

    Dimensions:

    82 X 33 X 13 cm.

     

    Closed Chamber Volume:

    2.6 L.

     

    Open Chamber Volume:

    1.0 L.

     

    Soil Collar Diameter:

    23 cm.

     

    Weight:

    9.0 kg.

     

    Construction:

    Steel electrically sealed enclosure.

     

    Connections:

    Either 10, 20, or 30 ACE station docking port versions, 2 battery ports, two Data card ports and an RS232 port.

     

    Dimensions:

    30 X 30 X 15 cm.

Opti-Sciences, Inc.

8 Winn Ave

Hudson, NH 03051, USA

Phone: (603) 883-4400

Fax: (603) 883-4410