HAMILTON's pHeasy Technology
Ensures accurate measurements without recalibration and predicts loss of measurement accuracy.

Stable reference systems are the heart of reliably functioning, long-lasting electrodes. In pH measurement up till now, the user was not spared the need for frequent calibration. The reason for this lies in shifting reference potentials due to chloride loss in the reference electrolyte. However, contaminated and partially clogged diaphragms also contribute considerably to changing properties in pH electrodes, which can only be resolved with a fresh calibration. For pH measurements where a very high degree of accuracy is required, it should therefore be sufficient if the pH sensor is calibrated just before measuring. But in industrial applications - especially in the case of online pH measurement - this is possible only with a great deal of effort, if at all. Even if a calibration with certified pH buffers is correctly carried out, the very next measurement will not necessarily be accurate! Depending on the age of the electrode or, more precisely, the state of the diaphragm and the chloride content in the reference electrolyte, different diffusion potentials may occur in buffers and measurement medium. Technically speaking, it is impossible to eliminate this source of error entirely, but with pHeasy technology it is possible to detect it online!

HAMILTON, with its pH glasses and the ingenious inner buffer, has built true long term stability into pHeasy electrodes.

pH measurement with pHeasy® has many advantages

pHeasy® technology consists of these hardware components: clog-free SINGLE PORE hole diaphragm, patented POLISOLVE electrolyte, extremely stable reference outlet, and CheckRef outlet. The difference in potential between REF and CheckRef is measured with a Redox or pH inlet and reveals the uncertainty of the measurement. By means of limit contacts, warnings and alarms (for example at 30 and 50 mV) can be triggered.

  • The measuring device can provide notification of needed replacement of the electrode.
  • The Checkref provides early detection and monitoring of reference poisons. This is because the pHeasy Checkref is positioned closer to the junction than the sensor reference.
  • Interfering diffusion potentials can be monitored in-situ using pHeasy®.

Never recalibrate

With pHeasy® only one calibration at the start of operation is needed.


  • pH 0 - 14
  • Temperature range:
  • Pressure range: 0 - 6 bar 0 - 60°C (pHeasy);
  • Certificate 0 -130°C (pHeasy HT)
  • Serial number
  • Pt 1000

Simple pHeasy® alarm signal

No recalibrating thanks pHeasy®

Recognize hidden inaccuracies

  • Every measurement solution produces a certain diffusion potential across the reference system. The error arising from this is small, as long as the reference system still has a high chloride concentration.
  • Over time the electrode looses chloride, and the measurement error increases during the measurement depending on the medium. Needless to say, this error is undetectable in the pH buffer solutions due to the buffer composition, and is not removed during calibration. The result is an inaccurate measurement.
  • That is why old electrodes are less accurate. pHeasy® monitors these hidden inaccuracies!