pH Sensor

Pi’s pH sensor- pHSense for potable water and process applications

The pHSense range of online pH meters from Pi utilize the very latest and best pH sensors available in the world today for measuring the online pH of any aqueous solution. They are patented gel filled sensors with integral reference which uses no reagents, are extremely stable, and have reduced maintenance and reduced whole life costs. The junction, usually the source of error with current pH sensor technology is made from an electrochemically active solid resulting in a more robust pH sensor.

Online pH meters and pH controllers are one of the most common analyzers in use today in water treatment and process plants and yet online pH meters cause continual problems for their operators. What is needed is a stable, reliable, online pH meter for a reasonable cost. That is exactly what you get with the pHSense and the pHSense Automatic Calibrator.

The pHSense sensors and flow cells are available with different controllers giving you the same great performance with different communication, display, and control options. With the pHSense range of online pH meters, you get everything that you need – and nothing that you don’t.

The sensor at the heart of the Process Instruments online pH meter is a patented gel filled glass electrode. This pH electrode is far superior to many online process pH electrodes on the market and is designed for a long life, low drift and high reliability. Unlike many pH analyzers, you don’t need to search through hundreds of pH electrodes to find one that works in your process as the pHSense electrode works in all environments from pH 2 to 12 and in conductivity from 0µS upward. Although they command a higher price in the market place these sensors are more than cost effective with their longer life and considerably lower maintenance requirements, typically only needing calibration once per two or three months. Despite the superior functionality that the pHSense has to offer, the purchase costs are less than or comparable to, its competitors!

The pHSense online pH meter takes away the requirement for continual calibration and re-calibration of the pH meter by operators as it utilizes an extremely stable pH electrode. The pHSense will calculate a ‘degree of confidence’ in its own calibration and let you know if its confidence is low. If the pH meter detects a fault in the pH sensor then it gives instructions on the display as to what the fault may be, with full on board fault diagnostics.

The online pH meter is capable of full PID control and is equipped with process control options, data-logging, relay outputs, serial communications, (TCP, Ethernet, Modbus are available now with Profibus available soon). Remote Access of the pH meter (including remote access to all control options) is available via the internet, and via a LAN. In fact the pHSense has all the options you could want in a pH meter whilst maintaining a low cost and great value for money.

  • Stable and reliable online pH meter
  • On board diagnostics
  • Auto calibration recognition
  • Low purchase cost
  • Long life pH sensors
  • Remote access and SMS text alarms

pH sensor

Pi’s pH Sensor for waste water

  • Remote Sites
  • Cooling Towers
  • Food Preparation
  • Paper Mills

Anywhere you have a requirement to measure pH is a suitable application for the pHSense. The pHSense online pH meter range is particularly suited to working in sites where reliability and ease of use are most important.

Remote Water Treatment Plant

Small water treatment plants, secondary disinfection plants etc. tend to suffer from similar problems wherever they are in the world. The first is lack of communications SCADA infrastructure. The cost of which to install can be prohibitive. The second is the lack of a central DCS control infrastructure, again the installation of which can be cost prohibitive. The third is the remote location. Often these water plants are in remote and difficult to access locations when the weather can sometimes cut them off for weeks at a time.

With these three issues facing many water engineers around the world a low cost solution providing solutions to all three issues is available from Pi. A CRIUS® controller has the on board capacity to provide small scale SCADA, and full online PID control whilst the sensors (e.g. chlorine, pH, Turbidity etc.) are suitable for long term operation without operator intervention.

When, in 2009 Cork County Council in Ireland needed exactly this functionality on 20 small, remote sites they installed CRIUS analyzers from Pi to great effect.

To demonstrate the remote access capability of the CRIUS® please click here.

To learn more about the control capability of the CRIUS® please click here.

To hear more about other customers in your country using the CRIUS® multiparameter controllers in a similar way why not contact us?

Wastewater Effluent Outlet

As increasing environmental regulations are being applied to industry all over the world there is a requirement for a single controller that can measure the online pH of multiple streams, can provide the control to automate pH neutralization, can datalog the whole pH neutralization process and can communicate back to the appropriate personnel if anything goes wrong.

That requirement can be met by the Pi CRIUS® pHSense. These two controllers can take in multiple pH sensors, provide up to eight fully functional PID control channels, datalog all inputs and outputs, and provide a machine to machine remote access capability which can email datalogs, alarms, can text alarms etc.

This fully integrated measurement control and communications controller comes at a small fraction of a cost of putting together a system with PLCs, instruments and modbus etc.

Taking advantage of this functionality a considerable sum of money was saved whilst more than fully complying with the requirement of the EPA in Ireland.

As described in a separate brochure, the pHSense can come equipped to automatically clean itself at user defined intervals with all the benefits of no operator intervention for 6 months. The Autoflush is particularly useful in food preparation, pulp and paper, and many applications where there is likely to be a build up of solids in the sample.


The whole range of pHSense pH meters can be fitted with additional sensors such as chlorine or ORP. Please ask your local distributor for more details.