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Enabling better global research outcomes in soil, plant & environmental monitoring.

MO-200 Portable Oxygen Meter

The MO-200 is designed to measure 5 – 100% oxygen while the handheld meter displays and stores measurements. The wide measurement range allows it to be used for applications either in the soil or in the lab with the available diffusion or flow-through heads. The sensor is calibrated to ambient air making it very easy to calibrate. An aluminium housing that is filled with epoxy allows the sensor to withstand harsh conditions.

  • Designed to measure 0 – 100% Oxygen in soil, growth media, air, or in-line tubing (flow-through applications)
  • Includes temperature sensor to compensate for temperature changes
  • Integrated heater prevents condensation for use in conditions where relative humidity can reach 100%
  • Available in sensor-only version with pigtail leads (for dataloggers) or with handheld meter

Accessories
All Apogee oxygen meters can be purchased with attachments to facilitate measurements in soil/porous media or inline tubing.

Model AO-001:
Diffusion head designed for measurements in soil/porous media. The diffusion head maintains an air pocket and provides protection to the permeable Teflon membrane where gas diffusion occurs.

Model AO-002:
Flow through head designed for inline measurements. The flow through head allows connection of tubing via ¼ inch barbed nylon connectors.

In applications with high humidity, condensation can occur on the Teflon membrane, blocking the diffusion path of the sensor. To prevent this, a resistive heater is included to raise the temperature of the membrane approximately two degrees above ambient temperature.
*Measurement of oxygen below 1% requires special calibration. Contact Technical Support for more details.

Memory
  • 99 manually stored data points
  • Automatically store 99 consecutive 30 minute averages
  • 99 daily averages
Range  5 to 100% oxygen
Response Time  14 seconds
Stability  ± 0.1% oxygen under stable atmospheric conditions
Repeatability  ± 0.1% oxygen
Display  4.2 by 2.8 cm
Power Requirement  Standard 3V coin cell battery
Operating Environment
  • 0 to 50°C
  • < 90% non-condensing relative humidity up to 30°C
  • < 70% relative humidity from 30 to 60°C
  • 60 to 150 kPa
Cable
  • 2 meters of twisted-pair wire
  • Foil shield
  • Santoprene jacket
  • Longer cable lengths are available in multiples of 5 meters
Weight
  • Meter: 80 g
  • Sensor and wire: 175 g
Diffusion Head
  • 3.5 cm tall by 3.5 cm diameter
  • 125 mesh screen
  • Creates air pocket
Flow-Through Head
  • 3.2 cm long by 3.2 cm diameter
  • 1/8” barbed adapters
  • For hose connections
Warranty 1 year against defects in materials and workmanship

Apogee Instruments MO-200 oxygen meters consists of a handheld meter and a dedicated oxygen sensor connected by cable. The separate sensor consists of a galvanic cell sensing element (electrochemical cell), Teflon membrane, and signal processing circuitry mounted in a stainless steel housing (or ABS plastic housing for use in acidic environments). The MO-200 oxygen meter includes manual or automatic data logging features for making spot-check measurements or monitoring oxygen concentration over time.

The sensors on Apogee MO-200 oxygen meters are built with an anodised aluminium housing (or ABS plastic housing for use in acidic environments) and are designed to be installed in soil/porous media or sealed chambers, in addition to air. To facilitate the most stable readings, sensors should be mounted vertically, with the opening pointed down and the cable pointed up. This orientation allows better contact between the electrolyte and signal processing circuitry.

Apogee oxygen sensors can be used in conjunction with carbon dioxide sensors to help improve the characterisation of soil respiration. Typically, soil oxygen sensors use a galvanic cell to produce a current flow that is proportional to the oxygen concentration being measured. These oxygen sensors are buried at various depths to monitor oxygen depletion over time, which is then used to predict soil respiration rates. Apogee oxygen sensors are equipped with a built-in heater to prevent condensation from forming on the permeable membrane, as relative humidity can reach 100 percent in soil.