July 10, 2017 – Routine sensor replacement is a necessary maintenance step in continuous online pH monitoring. The Sensorex SD7500 Universal Differential pH Probe is designed to extend the working lifetime of sensors. Universal compatibility with virtually any brand of conventional pH transmitter enables upgrade of existing sensors for industrial and municipal wastewater treatment and neutralization; metal finishing and plating; wet fume scrubbers; chemical processing; and other online water quality and process applications.
The SD7500 probe measures process pH differentially with three electrode sensors: a process pH electrode, a pH reference (actually a second measuring pH electrode in a known pH 7.0 buffered cell solution protected by a replaceable salt bridge reference junction), and a titanium ground electrode.
The three electrode design, coupled with Ryton Polyphenylene Sulfide (PPS) body construction, resists process contamination. The double junction construction of the replaceable salt bridge further guards against fouling, even in highly aggressive chemical environments. Automatic temperature compensation with a Pt1000 RTD ensures pH measurement accuracy over a wide temperature range.
Differential pH sensors are designed so the double junction salt bridge and the buffered reference cell solution can be replaced in the field by on-site operators. 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 integration into new systems.
