DFRobot - Gravity: Analog Dissolved Oxygen / DO Sensor Meter Kit for Arduino

This Gravity analog dissolved oxygen sensor kit adds water oxygen measurements to aquaculture, aquarium, and environmental science projects. A galvanic probe measures dissolved oxygen over a 0–20mg/L range without requiring polarization time, while the signal converter board connects to a compatible controller through a Gravity analog interface. The replaceable membrane cap and filling solution support routine maintenance, and a spare membrane cap is included. Paired with a controller, this DO sensor kit provides a starting point for a custom meter or multi-parameter water monitor. Required 0.5 mol/L NaOH filling solution is not included; the probe must be prepared and calibrated before use.

Galvanic Probe with No Polarization Wait

This dissolved oxygen sensor uses a galvanic probe, removing the polarization wait associated with probes that require electrical polarization before measurement. This design is useful for periodic sample checks and hands-on water experiments after the probe has been prepared and calibrated. No polarization time does not mean an instant reading: the specified response reaches up to 98% within 90 seconds at 25℃, so measurements should be taken after stabilization.

Replaceable Membrane and Filling Solution for Routine Maintenance

This DO sensor kit uses a replaceable oxygen-permeable membrane cap and filling solution, allowing routine servicing without replacing the full sensor assembly each time. A spare membrane cap and two plastic droppers are included to support preparation and maintenance. Replacement intervals depend on water conditions: the listed membrane interval is shorter in muddy water than in clean water. This serviceable design makes consumable maintenance part of the monitoring routine.

Gravity Analog Connection for Custom DO Meters

This dissolved oxygen sensor kit connects the probe to the converter board through BNC and provides a 0–3.0V analog signal. The board accepts a 3.3–5.5V supply, supporting suitable Arduino and ESP32 ADC inputs. The included Gravity cable simplifies connection to compatible expansion hardware. Raspberry Pi projects require an external ADC. Arduino preparation, calibration, and measurement examples provide a practical route to a custom display or data logging system.

Arduino Dissolved Oxygen (DO) Sensor Connection Diagram

SPECIAL INSTRUCTION:
Due to the International Import and Export Policy, the corrosive solution (acid & alkaline solution) cannot be delivered by air transportation. The filling solution is not included in the kit. You have to purchase it from the local shop or deploy the solution by yourself, refer to WiKi FAQ-Q4. It can’t work without a filling solution! Please be cautious with the purchase!

Note:

• 1. The filling solution is 0.5 mol/L NaOH solution. You need to pour it into the membrane cap before use. Please be cautious with the operation because the solution is corrosive. Please wear gloves! If the solution accidentally drops onto the skin, wash your skin with plenty of water immediately.
• 2. The oxygen permeable membrane in the membrane cap is sensitive and fragile. Be cautious when handling it. Fingernail and other sharp objects should be avoided.
• 3. The DO sensor will consume a little oxygen during the measurement. Please gently stir the solution and let the oxygen be distributed evenly in the water.

• 0–20mg/L dissolved oxygen detection range
• Galvanic probe with no polarization time required
• Replaceable filling solution and membrane cap for routine maintenance
• Spare membrane cap and preparation droppers included
• 3.3–5.5V signal converter board supply with 0–3.0V analog output
• BNC probe connection and Gravity analog interface
• 2-meter probe cable for flexible placement
• Arduino preparation, calibration, and measurement examples available

• Type: Galvanic Probe
• Detection Range: 0~20mg/L
• Response Time: Up to 98% full response, within 90 seconds (25℃)
• Pressure Range: 0~50PSI
• Electrode Service Life: 1 year (normal use)
• Maintenance Period: Membrane Cap Replacement Period: 1~2 months (in muddy water); 4~5 months (in clean water) Filling Solution Replacement Period: Once every month
• Cable Length: 2 meters
• Probe Connector: BNC

• Operating Voltage: 3.3~5.5V
• Output Signal: 0~3.0V
• Cable Connector: BNC
• Signal Connector: Gravity Analog Interface (PH2.0-3P)
• Dimension: 42mm * 32mm

• Galvanic Dissolved Oxygen Probe with Membrane Cap x1
• Spare Membrane Cap x1
• Signal Converter Board x1
• Gravity Analog Sensor Cable x1
• Waterproof Gasket x2
• Screw Cap for BNC Connector x1
• Plastic Dropper x2