pH Meter - Calibration

Video Instruction

What is calibration?

Calibration is a vital process that involves evaluating and adjusting the precision and accuracy of equipment. This process is often intended to minimize the bias in instrument reading, and it is an important component of analytical chemistry.

For the pH meter, it is possible to have small changes in electrode output over time, as well as from one electrode to another. For these reasons, the instrument should be calibrated periodically to ensure accurate and reliable measurements.

One, two, or multipoint calibration should be performed using fresh buffer solutions. Buffer solutions should cover the pH ranges of interest. Generally, three buffer solutions are required for a multipoint calibration - one buffer solution below pH 7, one at pH 7, and one buffer solution above pH 7.‚Äč

How to calibrate Orion 410A pH meter

  1. Make sure the pH meter is appropriately plugged in.
  2. Press the button to select CALIBRATE mode.
  3. Clean the pH electrode with deionized water, and gently wipe it dry with Kimwipe.
  4. Place the pH electrode in the pH7 calibration solution.
  5. Press "yes" and wait until the reading shows that pH = 7 and 'ready'.
  6. Press "yes" to confirm the calibration at pH7.
  7. Clean the electrode thoroughly with deionized water again, and wipe it dry with KImwipe.
  8. Repeat steps 4-6 with pH4 buffer solution.
  9. Measure pH of your sample solution(s).

Remember to clean the electrode with DI water and dry with Kimwipe between any calibration or sample measurements!