pH Sensor Calibration
What is pH Sensor Calibration?
pH Sensor Calibration is the process of adjusting the pH Sensor to read values accurately according to standards. It should be performed approximately every 1-3 months using reference buffer solutions, known as pH Buffer Solutions, as the calibration standard.
The Elxense pH Sensor uses 3 pH Buffer Solutions for calibration: 4.00, 6.86, and 9.18.
Example pH Buffer Solutions
How do you know when to calibrate?
The easiest and cheapest method is to use a simple pH Test Kit (which is inexpensive) to do a rough check approximately once a month. Compare the Sensor reading with the pH value from the Test Kit's color comparison. If they're close, calibration is not needed.
Example of a simple pH Test Kit
Calibration Steps
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Set the operating mode to Manual and turn CO₂ OFF.
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Open the device settings and navigate to the pH page as shown.
- Press the pH Sensor Calibrate button. The calibration screen will appear as shown.
- Dip the pH Sensor into pH Buffer Solution with a value of 4.00 or 4.01 and wait until the reading stabilizes. Then press the 4.01 button as shown. (In this example, suppose the stable reading shows pH 3.56.)
- Dip the pH Sensor into pH Buffer Solution with a value of 6.86 and wait until the reading stabilizes. Then press the 6.86 button as shown. (In this example, suppose the stable reading shows pH 6.78.)
- Dip the pH Sensor into pH Buffer Solution with a value of 9.18 and wait until the reading stabilizes. Then press the 9.18 button as shown. (In this example, suppose the stable reading shows pH 9.05.)
- After pressing all 3 buttons, the display will return to the pH page. Calibration is now complete.
pH Sensor Maintenance When Not in Use
pH Sensors deteriorate quickly if the probe tip dries out. If you need to shut down the pool system or there's no water circulation for an extended period (e.g., tile repair, pool leak), store the pH Sensor probe tip submerged in KCl 3.3M solution to prevent premature deterioration. Example KCl 3.3M shown below:
Did you know? pH Sensors are consumable components that degrade over time, typically lasting 6-12 months. Symptoms of deterioration include gradually drifting readings, and after recalibration, accuracy only lasts a short time before needing recalibration again.