PH Sensor


Table of contents

  1. Summary
  2. Maintenance
  3. Calibration
    1. Materials
      1. Hardware
      2. Software
    2. Calibration Steps
  4. Notes
  5. JSON


A low cost PH sensor. The pH probe measures the hydrogen-ion activity in water-based solutions.

Name: Grove - PH Sensor Kit (E-201C-Blue)


Calibration: Calibrated against 2 known buffer solutions

Type: Analog

Operational Range: 0 to 60 degrees C

Unit: N/A

Range: 1 to 14

Maintenance: ~1 year

Life Expenctancy: 2 years


The probe must be dipped into a buffer solution of pH 7 or distilled water between detecting different solutions.

The electrode can be soak in 4%HF for 3-5 seconds, rinsed with distilled water, then soaked in 3.3mol KCl.





Grove-PH Sesnor kit Seeeduino Lotus 2 solutions with known pH


Arduino IDE

Calibration Steps

  1. Set up the Arduino.
  2. Download the demo code from the link in the summary and paste the whole file into the root of the Arduino.
  3. Open the pH_meter_V1_1 with the Arduino IDE.
  4. Flash the device.
  5. Place the probe in calibration solution A. Record the voltage.
  6. Rinse the probe in distilled water.
  7. Place the probe in calibration solution B. Record the voltage.
  8. The formula for k is (pH of solution A - ph of solution B)/(voltage of solution A - voltage of solution B)
  9. The formula for Offset is [(pH of solution A + ph of solution B)-k(voltage of solution A + voltage of solution B)]/2
  10. Change the Offset value in the code (line 10).


This sensor may not be submerged in liquid for a long period of time.

When not in use, the probe should be in the sleeve with a solution of 3.3mol KCL.


  name: "ph",       # string
  data_type: "pH",  # string
  data_value:       # float