How to Calibrate the pH220S Soil pH Meter

Calibration is essential to ensure any pH meter produces accurate and repeatable results. The pH220S, which features automatic buffer recognition, along with an ability to calibrate up to three buffer points, makes the task of calibration effortless.

Figure 1 Watch an Instrument Choice Scientist demonstrate how to calibrate the pH220S soil pH meter here.

To perform a calibration, you will need;

• The pH220s with the electrode;
• Distilled or deionised water;
• pH buffers, pH 4, and pH 7.

1. Gently remove the electrode storage cap and rinse the electrode in distilled or deionised water.
2. Turn the pH meter on by pressing the ‘POWER’ button.
3. To enter the calibration mode; Press the ‘HOLD’ button once the hold icon appears on the screen. Then, press the downward-facing arrow once. After pressing the downward arrow, the top of the screen will say the required buffer solution, and the bottom will display ‘CAL.’ Note: always start with pH7 as the first buffer solution.
4. Place the electrode into the requested buffer solution.
5. Once immersed, press ‘HOLD’ once. The digits will flash on the screen as the device is calibrating.
6. When the calibration of this buffer is complete, the display will say ‘END.’ Then, the meter will automatically return to measurement mode.
7. The first point of calibration pH 7 is complete.
8. To calibrate to a second point, start by rinsing the electrode in distilled water.
9. Press the ‘HOLD’ button once, and the hold icon will appear on the screen. Then, press the downward-facing arrow once. After pressing the downward arrow, the top of the screen will show the required buffer solution, and the bottom of the screen will display ‘CAL.’ This time to calibrate to another buffer solution, press the downward-facing arrow to change the requested buffer. Press the arrow until pH4.00 appears on the screen.
10. Place the electrode into the requested buffer solution.
11. Once immersed, press ‘HOLD’ once. The digits will flash on the screen as the device is calibrating.
12. When the calibration of this buffer is complete, the display will say ‘END.’ The meter will automatically return to measurement mode.
13. The two-point calibration is now complete. Rinse off any remaining buffer using the distilled water, and the meter is now ready to take soil pH measurements.

CONCLUSION

Performing a two-point calibration on the pH220s Soil pH Meter is a straightforward task that takes less than five minutes to complete. Calibration significantly improves the reliability and accuracy of the instrument.

If you have any questions on how to perform a calibration on the pH220s Soil pH Meter or want to know more about the instrument, contact us!

Additional Links

• View the Soil pH Meter with Separate Electrode features and specifications here.
• Watch ‘How to Calibrate the pH220S Soil pH Meter with Seperate Electrode' again.
• Need pH buffers? View the full range here.