The AP200 is a complete, integrated CO2 and H2O atmospheric profile system. It measures carbon dioxide (CO2) and water vapor (H2O) concentration from up to eight intakes, which are normally spaced along the height of a tower to give a vertical profile. The AP200 is often used in conjunction with an eddy-covariance system to measure the storage term and give a more complete measure of the surface gas exchange.
Primary:
Secondary:
Note: Contact the Micromet Group at Campbell Scientific for questions or updates regarding the datalogger program. |
System Enclosure |
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Operating Temperature | -30° to +45°C |
Power Requirements |
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Dimensions | 52.1 x 44.5 x 29.7 cm (20.5 x 17.5 x 11.7 in.) |
Weight |
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Pump Module |
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Pump Type | Dual-head diaphragm pump with a brushless dc motor |
Mounting | Mounted in an insulated, temperature-controlled box inside system enclosure |
Control | Pumping speed is automatically controlled to maintain the pump inlet pressure at the set point |
Maximum Pumping Speed | 9.0 liters per minute (LPM) |
Pressure Sensor Range | 15.0 to 115.0 kPa |
Heater | 8.0 W (turns on/off at 2°C) |
Warm-up Time | ~50 min (from -30° to +2°C) |
Fan | 0.7 W (turns on at 50°C and off at 45°C) |
Valve Manifold |
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Mounting | Mounted inside system enclosure |
Inlets | Eight air sample inlets plus one inlet for zero, one inlet for CO2 span, and one inlet for H2O span |
Connections | 0.25-in Swagelok |
Mass Flow Sensor | 0 to 1.0 standard liters per minute (SLPM) |
Heater | 8.0 W (turns on/off at 5°C) |
Warm-up Time | ~20 min (from -30° to +4°C) |
Fan | 0.7 W (turns on at 45°C and off at 43°C) |
Intake Assembly |
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Filter | 1.0-in diameter, sintered stainless-steel disk filter, 10-micron pore size |
Orifice Heater | 2 kohm (0.07 W at 12 Vdc) |
Mixing Volume | 750 mL |
Sample Connection | 0.25 in. Swagelok |
Number of Connections for Heater Cable Entry Seals | 3 (1 in, 2 out) |
Cable Diameter for Heater Cable Entry Seals | 2.8 to 6.6 mm (0.11 to 0.26 in.) |
Wire Diameter for Heater Cable Screw Terminals | 26 to 12 AWG |
Wire Stripping Length for Heater Cable Screw Terminals | 5.0 mm (0.2 in.) |
Screw Tightening Torque for Heater Cable Screw Terminals | 0.4 N•m |
Orifice Inside Diameter | 0.178 mm (0.007 in.) |
Dimensions | 31 x 12.5 x 19 cm (12 x 5 x 7.5 in.) |
Weight | 1.4 kg (3.1 lb) |
AP200 CR1000(X) Program.
Compatible with the LI-850.
Note: For those with the LI-840 contact Campbell Scientific for compatible code.
A software utility used to download operating systems and set up Campbell Scientific hardware. Also will update PakBus Graph and the Network Planner if they have been installed previously by another Campbell Scientific software package.
Supported Operating Systems:
Windows 11 or 10 (Both 32 and 64 bit)
Number of FAQs related to AP200: 52
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The LI-840A uses a heater to maintain its sample cell at +50°C. Therefore, it consumes a lot more power at lower temperatures. Below 0°C, the valve heater also requires some power to keep the valves warm.
Numbering this way helps reduce the time skew between measurements of the intakes. To illustrate this, consider a parcel of air that moves through the intake tubes at approximately 0.5 m/s. If the longest tube is 60 m longer than the shortest tube, its travel time is two minutes longer than the shortest tube. Sampling from the shortest tube first means that the air samples enter each tube at the same time.
The intake heaters are wired in parallel, so that each heater sees a nominal 12 Vdc.
The number of intakes required at a site depends on the characteristics of the canopy. For example, the canopy’s height and density directly affect the change in CO2 and H2O concentrations. Order enough intakes to accurately profile these concentration changes. The AP200 may be ordered with anywhere from four to eight intake assemblies.
The spacing depends on the canopy and atmospheric conditions. It is important to know where the concentration gradients are the steepest.
For example, in a low agricultural crop canopy, it may be appropriate to use a logarithmic distribution within and near the top of the canopy, and a linear distribution above the canopy: 0.2 m, 0.4 m, 0.8 m, 1.6 m, 3.2 m (logarithmic) and 5 m, 7 m, 9 m (linear).
Yes. The LI-840A has active pressure compensation that corrects its measurements for sample cell pressures from 15 to 115 kPa.
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