Knight:pH meter/Calibration

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Overview

Some quick notes on how to calibrate our pH meter.

Materials

  • pH standard solution 4.0
  • pH standard solution 7.0
  • pH standard solution 10.0
  • 1 beaker to collect washes
  • Squirt bottle with distilled water
  • Kimwipes

Procedure

  1. Raise the electrode out of the storage buffer.
  2. Rinse with distilled water from a squirt bottle over a beaker used to collect washes.
    • Do not rinse the electrode into the soak beaker.
  3. Touch electrode gently with Kimwipe to remove excess fluid.
  4. Press the CAL key.
  5. Press the CLEAR key twice to remove existing calibration.
  6. Immerse the tip of the electrode into pH buffer 4 bottle.
  7. Press the READ key.
  8. Wait until the Auto-Eye stops flashing. The pH meter should read 4.00.
  9. Rinse with distilled water from a squirt bottle over a beaker used to collect washes.
  10. Touch electrode gently with Kimwipe to remove excess fluid.
  11. Immerse the tip of the electrode into pH buffer 7 bottle.
  12. Press the READ key.
  13. Wait until the Auto-Eye stops flashing. The pH meter should read 7.00.
  14. Rinse with distilled water from a squirt bottle over a beaker used to collect washes.
  15. Touch electrode gently with Kimwipe to remove excess fluid.
  16. Immerse the tip of the electrode into pH buffer 10 bottle.
  17. Press the READ key.
  18. Wait until the Auto-Eye stops flashing. The pH meter should read 10.01.
  19. Press the CAL or EXIT key to exit the calibration mode.
  20. Rinse with distilled water from a squirt bottle over a beaker used to collect washes.
  21. Touch electrode gently with Kimwipe to remove excess fluid.

The pH meter is calibrated for measuring the pH of most buffers and solutions. For more exact measurements or to pH solutions with more extreme pH, you may need additional/alternate calibration buffers.

Notes

  • The electrodes of pH meters are both fragile and expensive. Be careful when immersing it to not hit it against the beaker.

References

  1. [Manual]
  2. ISBN:0879697083 [AtTheBench]

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