Using the pH Meter
From Bridges Lab Protocols
This is for the Mettler Toledo FiveEasy Plus meter
Calibration
- Open up the hole on the top of the probe
- Rinse the meter with water
- Place in pH 4.00 standard and press Cal, once the pH has stabilized press Read.
- Repeat with pH 7.00 and pH 10.00 standards.
- When complete press Read again
Measuring pH
- Place meter in sample with stirring, make sure the stir bar is not hitting the probe.
- Press Read to start measuring the sample.
- Adjust pH with NaOH/KOH or HCl depending on the counter-ion. If you are using a very weakly buffered solution, use diluted acids/base. If adjusting pH of a buffer stock you may need to use the concentrated acid or pellets.
- When finished rinse off the probe, close the hole on the top and place in the storage solution (3M KCl)
