Sensorex debuts universal pH water quality sensor

The sensorex SD7500 works with any existing conventional pH transmitter. Photo credit: Sensorex

Routine sensor replacement is a maintenance step that is necessary in continuous online pH monitoring. However, the Sensorex SD7500 Universal Differential pH Probe extends the working life of sensors while also lowering maintenance frequency – without compromising accuracy and reliability. Compatible with virtually any brand of conventional pH transmitter, it also enables easy upgrades of existing sensors for industrial and municipal wastewater treatment and neutralisation, metal finishing and plating, and chemical processing, among others.

The SD7500 probe measures process pH differentially with three electrode sensors: A process pH electrode, a pH reference, and a titanium ground electrode. The result is a highly accurate differential pH measurement that is virtually unaffected by ground loop measurement errors.

The three electrode design, coupled with a durable Ryton® Polyphenylene Sulfide (PPS) body construction, is resistant against process contamination. The double junction construction of the replaceable salt bridge adds further protection against fouling, even in highly aggressive chemical environments. Additionally, the automatic temperature compensation with an accurate pt1000 RTD ensures pH measurement accuracy over a wide temperature range.

Differential pH sensors are designed in such a way that the double junction salt bridge and the buffered reference cell solution can be replaced in the field by on-site operators, at a much lower cost than total sensor replacement. Compared to conventional combination sensors, differential pH sensors provide measurements of greater stability – and over longer periods of time, with less downtime and maintenance. The lifetime of a typical sensor service usually ranges between three to five years.

With a self-powered preamp and combination sensor output, the SD7500 Differential pH Probe can be used with most conventional online pH/ORP transmitters and controllers. This enables drop-in replacement in existing process installations, as well as easy integration into new systems. Manufactured in the USA, Sensorex’s SD7500 probe is backed by a two-year limited warranty.