Using the pH Meter

Video

Calibrating the pH Meter

1. Obtain a beaker or large electrophysiology cup and a bottle of DI water. Set the cup under the pH and temperature probes.

2. Remove the bottle on the probe by unscrewing the cap. Carefully, slide the cap upward along the probe away from the blue bulb. Set the bottle aside in a safe place (Cabinet A is a good place) to avoid knocking it over.

3. Rinse the probes with DI water. Turn the pH meter on by pressing the power button.

4. Press the CAL/MEAS button to change the mode to calibration. Dip the probe into the first pH standard*. You may start at one of the extremes and work toward the opposite extreme (e.g. acidic to basic or viceversa).

* Make sure the bulb does not touch anything other than the solution.

5. The pH meter will begin calibrating by trying to equalize the measured pH (larger number) to the detected standard pH (smaller number). The word Ready will come on at the top of the display when the meter is done calibrating with that standard.

6. Remove the standard and rinse the probes with DI water.

7. Repeat steps 5 and 6 for the other standards, ensuring that you rinse the probes at the end. At the end of calibration, press the CAL/MEAS button again to switch to measuring mode. If not measuring right away, replace the bottle on the pH probe.

Using the pH Meter

1. Check to see when the pH meter was calibrated last. If longer than a month, it must be recalibrated; otherwise, you may continue with this protocol.

2. Obtain a large electrophysiology cup and a squirt bottle of DI water. Set the cup under the pH probe.

3. Remove the bottle on the probe by unscrewing the cap. Slide to the top up along the probe. Set the bottle aside in a safe place to avoid knocking it over.

4. Rinse the pH and temperature probe with DI water. Turn the pH meter on by pressing the power button.

5. Set the solution you are measuring on a magnetic plate and put a stirring rod in the solution. Turn on the magnetic stirring to a gentle mix. Ensure that the stirring rod does not start jumping.

6. Place the probes into the solution being careful not to let the stirring rod hit the blue bulb. Adjust the pH of the solution as desired. The screen will say READY when the pH is determined.

7. When done, turn the pH meter off, rinse the probes with DI water and replace the bottle on the pH probe.