Using the pH Meter

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)