AP200 CO2/H2O Atmospheric Profile System
Complete, Integrated System
Preprogrammed and low power
weather applications water applications energy applications gas flux & turbulence applications infrastructure applications soil applications


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 provide you with a more complete measure of the surface gas exchange.

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Benefits and Features

  • Fully integrated system
  • Requires only 13 W (average at 25°C and 12 Vdc)
  • Contains a Campbell Scientific CR1000 Measurement and Control Datalogger
  • Automatically performs CO2 zero and span
  • Automated temperature and pressure control
  • Datalogger program included


<dl><dt>Typical AP200 Installation</dt> <dd>1-27693 Heated Sample Intake Assemblies (from 4 up to 8)</dd>
<dd>2-9922 20 AWG Power Cable</dd>
<dd>3-28547 AP200 System Enclosure</dd>
<dd>4-15702 Tubing</dd>
<dd>5-Zero/Span Tanks and Regulators (not included)</dd>
<dd>6-Instrument Tower (sold separately)</dd></dl>

Detailed Description



  • CO2 concentration at each intake
  • H2O concentration at each intake
  • System diagnostic word


  • Sample flow rate
  • Sample cell pressure
  • Sample cell temperature
  • Other control variables

Note: Contact the Micromet Group at Campbell Scientific for questions or updates regarding the datalogger program.


System Enclosure

Operating Temperature -30° to +45°C
Power Requirements
  • 10 to 16 Vdc (voltage)
  • 13 W (average power at 25°C)
    Average power varies from 12.5 W above +35°C to 22.5 W at -30°C.
  • 3.75 A (45 W) maximum power (cold startup)
Dimensions 52.1 x 44.5 x 29.7 cm (20.5 x 17.5 x 11.7 in.)
  • 15.9 kg (35 lb) for AP200 base model
  • 1 kg (2.3 lb) for LI-840A
  • 272 g (10 oz) for CR1000KD
  • 154 g (5.4 oz) for CFM100/NL116

Pump Module

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

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

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 Program v.1.3 (15.7 KB) 10-07-2014

AP200 CR1000 Program.

Device Configuration Utility v.2.17 (46.4 MB) 02-13-2018

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 10, 8.1, 8, and 7 (Both 32 and 64 bit)

View Update History

Frequently Asked Questions

Number of FAQs related to AP200: 53

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  1. The molecular sieve is a direct replacement for the old magnesium perchlorate bottles. The molecular sieve may be used for any Campbell Scientific analyzer that used the old bottles.

  2. The molecular sieve is a non-hazardous material that can be shipped to any country.

  3. The molecular sieve has been demonstrated here by our engineering department to be effective at removing CO2 and H2O from the air sample. The change was made for two reasons:

    1. It was a safer alternative than using the previous chemicals.
    2. Increased shipping regulations for the chemicals limited the number of suppliers. 
  4. A non-zero value can be used to perform a zero/span on an interval that is not synchronized to midnight (for example, every three hours starting at 0100 hrs).

  5. 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.

  6. No. The AP200 requires flow from at least four intake assemblies for smooth operation of the pump.
  7. No. Because the AP200 has only eight inlets for air samples, it can only operate with a maximum of eight intake assemblies.
  8. The automatic zero/span function of the AP200 is designed to do both a zero and a CO2 span. However, it is possible to disable the CO2 span and do only a zero. To do this, set public variable CO2_SPAN_PPM =0.

  9. Possibly. For example, to measure advection because of a drainage flow on sloping terrain, an AP200 system could be deployed with two towers, upstream and downstream along the slope, with four intakes on each tower.

Case Studies

Tasmania: Ecological Research
The Warra long-term ecological research (LTER) site located in Southwestern Tasmania was founded in 1995......read more

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