Decoding the Working Principles of Electrochemical Oxygen Sensors


Gas sensors, pivotal in technology's evolution, extend beyond industry to impact daily life. Explore DFRobot's latest electrochemical oxygen sensor, uncovering its principles and applications. Whether curious about tech principles or practical scenarios, this project offers valuable insights. Join us in exploring the DFRobot oxygen sensor's fascinating world.

1 DFRduino UNO R3
1 IO Expansion Shield
1 Electrochemical Oxygen Sensor
1 Electrochemical CO Sensor
1 7.4V Lipo 2500mAh Battery


This Gravity: Oxygen Sensor (Calibrated) - I2C & UART is DFRobot's latest gas sensor, which features factory calibration, accurate measurement, high sensitivity, low power consumption. It has three output modes, I2C, UART and analog.


The sensor can measure with 0.1% vol accuracy in 0~25% Vol environment and its response speed is less than 15 s. We designed the sensor to work at 3.3v~5v and is compatible with various mainstream host controllers such as arduino,ESP32 and Raspberry Pi and etc. The sensor has a built-in threshold mode, which can simplify the development of the program.




The oxygen sensor is a metal-air type cell, consisting of an air cathode, an anode, and an electrolyte. When oxygen reaches the working electrode, it is immediately reduced to release hydroxide ions, 


then these hydroxide ions pass through the electrolyte to the anode (lead), where they undergo an oxidation reaction with the lead to produce the corresponding metal oxide. 

The above two reactions occur to generate an electric current, the magnitude of which depends accordingly on the oxygen reaction rate. The magnitude of the current is proportional to the concentration of oxygen. Thus we get the value of the oxygen content.





STEP1: Light candles

STEP2: Place the oxygen sensor and lit candle in the container

STEP3: The screen shows that the oxygen content decrease, and at the same time, the carbon monoxide in the container can also be detected.


More for Carbon Monoxide Electrochemical Sensor Project



Through this in-depth exploration of the working principles and practical applications of the DFRobot electrochemical oxygen sensor, we have not only gained profound insights into the technological mysteries behind it but also witnessed its practicality in the candle experiment. If you have any questions or suggestions, please feel free to leave a comment and let us know!

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