MIK-DO7011 Membrane dissolved oxygen sensor

The MIK-DO7011 is a membrane-type dissolved oxygen (DO) sensor based on the polarographic measurement principle. A membrane separates the sample from the sensor's working electrode, and the sensor measures the oxygen dissolved in an aqueous solution.

Oxygen diffuses from the water through a gas-permeable membrane to the working electrode, where it is reduced and produces a small current. The current is proportional to the oxygen partial pressure. Because oxygen solubility depends on water temperature, pressure and salinity, these factors affect the DO value.

• Dissolved oxygen: 0–20 mg/L
• Pressure: up to 0.6 MPa
• Temperature: 0–60 °C

• DO accuracy: ±3% of the measured value
• Temperature accuracy: ±0.5 °C
• Measurement error: <0.01 mg/L
• Zero oxygen reading: <0.01 mg/L
• Drift: <2% per month

The response time is 2 minutes (T90 at 20 °C).

Yes. A membrane sensor consumes oxygen during measurement, so the minimum flow rate across the membrane is 2.5 cm/s. Install the sensor where there is sufficient water movement, or use a flow-through arrangement.

• Membrane (breathable) thickness: 100 μm
• Air current: 50–80 nA
• Current at 0.1 mg/L; maximum current: 3.5 μA

Pt100, Pt1000, 2.252K and other temperature elements are available. Choose the element that matches your DO meter.

The specification lists a 4–20 mA output type. Please tell us whether you will connect the sensor to a DO meter or directly to a control system, so we can confirm the correct output configuration.

• Electrode shell: PVC or 316L
• Cable: 5 m, double shielded
• Weight: 1.85 kg

Asmik offers the MIK-DM2800 membrane dissolved oxygen meter for membrane DO sensors. Please make sure the meter supports the selected temperature element, and confirm compatibility with us before ordering.

Membrane DO sensors are generally calibrated in water-saturated air (100% saturation) and, if required, in a zero-oxygen solution. Allow the sensor to polarize before calibration, and follow the procedure of your DO meter.

• Clean the membrane regularly; deposits and biofilm reduce oxygen diffusion.
• Replace the membrane and electrolyte when the response becomes slow or unstable.
• Allow a polarization period after installation or maintenance.
• Recalibrate after maintenance.

• Install the sensor where water flow across the membrane is at least 2.5 cm/s.
• Mount it at a representative depth, away from direct aerator bubbles.
• Keep the membrane facing downward or at an angle to prevent bubbles from collecting on it.
• Make sure the sensor can be removed easily for cleaning and maintenance.

The MIK-DO7011 membrane sensor is a proven, cost-effective technology, but needs periodic membrane and electrolyte maintenance and a minimum water flow. Optical sensors such as the MIK-DO7017 consume no oxygen, have no flow requirement and need less maintenance.

Typical applications include aeration tanks and effluent in wastewater treatment, water plants, aquaculture and industrial water monitoring.

To help us select the correct configuration, please provide:

• Application and installation point
• DO range, water temperature, pressure and salinity
• Water flow conditions at the sensor
• Shell material (PVC or 316L) and temperature element
• Cable length and output requirement
• Whether a DO meter is required
• Quantity

Send your requirements to info@asmik.com or contact us via WhatsApp at +86 13325716921.