pH Meter Use, K. Cayemitte, 21 November 2024

Materials Needed

Kim wipes

Sample

pH Meter

pH buffer solutions (pH = 4, 7, and 10)

DI water in a squirt bottle

Nitrile gloves

Waste Container

Methods

1. Make sure the pH probe is attached to the pH meter and move the rubber stopper at the top so that the hole is uncovered, allowing air to move in and out of the pH meter to equalize internal pressure.

2. Press the power button to turn the meter on.

3. First, calibrate the pH meter: Take the probe out of the standing solution, gently wash it with DI water, and gently pat dry the outside of the probe with a Kimwipe. Don’t touch the Kim wipe to the central piece at the end of the probe.

4. Dip the first buffer solution (it is better to hold the meter so it is not touching the bottom), give the probe a gentle swirl in the solution, and press “cal”, wait until the meter stabilizes, and it should be within .1 of the stated pH of the buffer.

5. Gently wash the probe with DI water, gently pat the outside dry with a Kim wipe, and repeat step 3 with other buffer solutions.

6. Before taking a reading of your sample, place it back in one of the buffers and press “read” to determine if the meter is correctly reading the buffer.

7. Again, wash and dry the meter, place the meter in the sample, press “read”, wait for the meter to stabilize, and then record the pH measurement.

8. Clean and dry the meter.

9. ALWAYS MOVE THE RUBBER STOPPER BACK TO COVER THE HOLE WHEN YOU ARE FINISHED USING THE METER otherwise, the solution will evaporate.

10. Place the bottle of standing solution back on the end of pH probe.

11. Press and hold the power button to shut the meter off