pH Probe Options

By on August 13, 2010

An electronic pH probe typically uses a specially-prepared electrode with an ion-selective barrier that measures the hydrogen ion concentration in the water. A measurable potential is generated between this electrode and second electrode, which serves as the reference and is surrounded with a neutral pH buffer. The voltage generated is directly proportional to the water’s pH level.

Common pH probes

Fondriest Environmental offers a wide range of pH probe and meter options, capable of meeting a number of application needs.

YSI’s sonde-based version, the model 6561, works with any YSI 6-series multiparameter sonde and contains a “long-life” sealed gel reference, eliminating the need to refill. YSI 6561 pH SensorThese sensors have been carefully designed to perform under all ionic strength conditions, from seawater with a conductivity of 53,000 uS/cm, to “average” freshwater lakes and rivers with conductivities of 200 to 1500 uS/cm, and even pure mountain streams with conductivities as low as 15 uS/cm, which has historically been the most difficult medium with respect to accuracy, quick response to pH changes, and minimal flow dependence.

The Orion Star A211 benchtop pH meter provides ease of use while taking reliable, accurate pH measurements suitable for any general laboratory or QC application. The meter offers a full complement of GLP-related features. The meter can record and store up to 10 setup parameters and calibrations, a valuable feature for busy multi-user labs.
Thermo Orion Star A211 Benchtop pH Meter
For smaller scale projects, the NexSens WQ-PH offers a cost-effective pH monitoring solution, ideal for the classroom setting. The WQ-PH includes double junction electrodes and also utilizes a gel reference to minimize maintenance concerns. It offers quick response and long life in both lab and field applications. These sensors provide convenient, plug-and-play USB connectivity. They run without meters, batteries, or power supplies. Just plug one into a computer, install the included software, and it’s ready to go.

WQSensors Software comes free with WQ-PH sensors. It is a powerful sensor interface and data collection program that allows users to quickly calibrate, log, and analyze data from any WQSensor. Professional PDF reports are generated with the click of a button, and advanced options allow the user to adjust graph scaling, select time intervals, and more.

For additional pH technology, see our full pH sensor inventory. To learn more, call a Fondriest Environmental product specialist at 888.426.2151 or email

Leave a Reply

Your email address will not be published. Required fields are marked *