Gravity: Analog Dissolved Oxygen Sensor / Meter Kit for Arduino

This is a dissolved oxygen sensor kit. A dissolved oxygen meter is used to measure the dissolved oxygen in water, to reflect the water quality. It is widely applied in many water quality applications, such as aquaculture, environment monitoring, natural science, etc. 

There’s an old saying regarding keeping fish, “Good fish deserves good water”. Good water quality is very important to aquatic organisms. Dissolved oxygen is one of the important parameters to reflect water quality. Low dissolved oxygen in the water will lead to difficulty in breathing for aquatic organisms, which may threaten their lives.

The probe is galvanic, does not need polarization time, and stays available at any time. The filling solution and membrane cap are replaceable, leading to the low maintenance cost. The signal converter board is plug-and-play and works from 3.3V - 5V which makes it compatible with most popular microcontrollers such as ESP32, Raspberry Pi and Arduino. 

You may also check Liquid Sensor Selection Guide to get better familiar with our liquid sensor series.

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.

Dissolved Oxygen Probe：

1. Galvanic probe, no need polarization time

2. Filling solution and membrane cap is replaceable, low maintenance cost

Signal Converter Board：

1. 3.3~5.5V wide-range power supply, compatible with most Arduino microcontroller

2. 0~3.0V analog output, compatible with all microcontrollers with ADC function.

3. Gravity interface, plug, and play, easy to use

Dissolved Oxygen Probe

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

Signal Converter Board

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

Project 1. Analog Dissolved Oxygen Sensor Tutorial | DIY Arduino D.O. Meter

Introduction: Since measuring the parameter of water quality is a complex task, so measuring the dissolved oxygen in water is also not an easy task. That is why the Dissolved Oxygen Meter (DO Meter) available in the market is very expensive. That is why it is important to make your own Dissolved Oxygen Meter. So the Gravity Analog Dissolved Oxygen Sensor from DFRobot is one of the most popular and best Dissolved Oxygen Sensors that are available in the market.

This project will interface Gravity Analog Dissolved Oxygen Sensor with Arduino Board and 0.96″ OLED Display. Firstly, preparing the DO Sensor by filling the 0.5N Sodium Hydroxide Solution, then preparing the sensor for testing. Once the sensor is prepared, go through the Arduino Dissolved Oxygen Sensor calibration code & calibrate the sensor. And then finally making your own Dissolved Oxygen Meter & display the dissolved Oxygen value in OLED Display.

Project 2. Build KnowFlow: automatic water monitor

KnowFlow is the name of this water quality monitoring device, based on Arduino Uno. It can automatically monitor 5 parameters of water: pH, Temperature, Dissolved Oxygen, Electronic Conductivity, ORP.

• Central Control Unit: Arduino Uno (DFRobot Bluno in this case) and Expansion Shield (DFRobot Expansion Shield V7.1 in this case)
• Water Sensors: pH (pH probe and pH circuit board); EC (EC probe and EC circuit board); ORP (ORP probe and ORP circuit board); Temperature (temperature probe and temperature circuit board); Dissolved Oxygen (DO probe, BNC and circuit board); real-time clock circuit board
• Data Storage: Micro-SD module, Micro SD card
• Fit and fix: mounting plate, waterproof box( 200mm_150mm_75mm), waterproof joint
• Other parts: Cables (Wires), breadboard, bolts and nuts, screws, battery, double-sided adhesive, write on tape, small wrench, spiral cable wrap

Project 3. Calibrated Dissolved Oxygen Meter

Introduction: Are you working on a aquaponics or hydroponics project? Or you simply have a fish tank and want your fish to be happy? If yes, you'll probably need a way to measure dissolved Oxygen level.

Dissolved oxygen sensor Product WIKI

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