Selecting the appropriate pH sensor for your application is essential for accurate measurements and control. Before making a pH sensor selection, you should consider a few different factors: temperature & pressure effects on the pH sensor, pH sensor glass characteristics, and reference sensor characteristics. In this article, we’ll break down each of these factors to assist you in deciding on the correct pH sensor for your application!


Temperature & Pressure Effects On pH Sensors

One key element of selecting an appropriate pH sensor is considering the temperature and pressure of the application you plan to be using the sensor in. Higher temperatures and pressure will cause most pH sensors to age and deplete faster. Constant fluctuation of these factors will also shorten the lifespan of a pH sensor. If you plan on using a pH sensor in an application with high temperature and pressure, you should be sure that it has a bellow, which will limit the negative effects of the environment it’s in.


pH Sensor Glass

The next factor to consider when choosing the appropriate pH sensor for your application is the sensor’s glass. The glass surface on a sensor has inherent pores that act as nesting areas for H+ ions. The relationship between these H+ ions and the porous glass on the sensor is crucial for accurate measurements. If a pH sensor is being used in a high alkaline application, the pores in the glass may instead be filled with Na+ ions, causing the sensor to give lower pH readings than it should. The glass on a pH sensor will also age over time, causing the sensor to become sensitive to several kinds of ions, not just H+. By seeking out a sensor with the glass characteristics that are right for your application, you can get more accurate measurements and expand the lifespan of your pH sensor!


Reference Sensor Characteristics

One more factor to consider when choosing a pH sensor is the reference sensor characteristics. According to Yokogawa, 70% – 80% of pH sensor failures are caused by an issue with the reference junction. For this reason, it’s crucial to select the right type of reference junction for your application. The correct selection for your reference sensor will depend on the conditions and environment that the sensor will be exposed to. The four most common reference junctions are ceramic, PTFE, sleeve, and salt-sensitive glass. Click here to learn more about reference sensor characteristics from Yokogawa!


Shop pH Sensors Online or Contact Sentrol Inc. Today!

If you have any questions about selecting the pH sensor that’s right for your application, please don’t hesitate to contact our team at Sentrol Inc! We provide facilities in New England, the Mid-Atlantic, and Eastern Canada with instrumentation sales, repair, calibration, and much more! Call us today at (888) 877-1778 or fill out the contact form on our website, and we’ll get back to you as soon as possible! Shop our online store to purchase pH sensors from industry-leading manufacturers!