Arduino pH sensor: Difference between revisions
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== Theory == | == Theory == | ||
=== Briefly === | |||
An ideal pH sensor because H<sup>+</sup> ions. Ranging linearly: | An ideal pH sensor because H<sup>+</sup> ions. Ranging linearly: | ||
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See more about impedance and Arduino ADC at https://www.e-tinkers.com/2020/07/a-review-on-seeed-studio-ph-and-ec-sensor-kits-part-1/ | See more about impedance and Arduino ADC at https://www.e-tinkers.com/2020/07/a-review-on-seeed-studio-ph-and-ec-sensor-kits-part-1/ | ||
=== Nernst Equation === | |||
=== 1 === | |||
=== 1 === | |||
=== 1 === | |||
== Calibration == | == Calibration == | ||
Revision as of 19:35, 4 March 2026
Introduction
3 major commercially available or mass-produced solutions:
- Atlas Scientific and Gravity analog pH Kit with board, sensor and buffer solutions. Hiqh quality, not open source.
- DFRobot Gravity: Analog pH Sensor Kit
- Other (Chinese) manufacturers.
- Seeed Studio
If the pH electrode is labotorary grade, it is not designed for submerging into measuring solution permanently. Thus, use an industrial-grade pH electrode (lifecycle about 3 years), but calibrate it at least twice every year.
Theory
Briefly
An ideal pH sensor because H+ ions. Ranging linearly:
- U = 0 @ pH 7
- U > 0 @ pH < 7
- U < 0 @ pH > 7
A high quality op amp is needed to amplify the voltage.
The pH electrode
- a passive sensor
See more about impedance and Arduino ADC at https://www.e-tinkers.com/2020/07/a-review-on-seeed-studio-ph-and-ec-sensor-kits-part-1/
Nernst Equation
1
1
1
Calibration
Code
References
https://www.e-tinkers.com/2019/11/measure-ph-with-a-low-cost-arduino-ph-sensor-board/
