Emerson Process Management/Rosemount Analytical

Emerson Process Management has introduced the Rosemount Analytical PERpH-X 3500 high-performance pH and ORP sensor. The company claims it is the industry’s first general-purpose pH sensor that includes advanced technologies for longer life in difficult processing applications, providing a lower total cost of ownership.

The Model 3500 combines the performance of the PERpH-X pH sensor family with the convenience of plastic-threaded connections for a wide range of mounting options. PERpH-X 3500 incorporates several design innovations for prolonged life, including improved pH glass electrode durability, increased reference electrode stability and overall mechanical design reliability. These features result in longer sensor life in challenging processes, faster response, less drift, higher accuracy, and minimized maintenance requirements, according to Emerson.

Most pH measurements fail due to fouled or poisoned electrolytes and clogged reference junctions, which are the most common reference electrode problems. The PERpH-X sensor family features an enhanced double junction electrode that excels in harsh applications, and the specially designed porous Teflon liquid junction has a large surface area to maintain a steady reference signal in dirty and fouling applications. The large surface area and high porosity also minimize junction potentials leading to accurate measurements without standardization.

The porous Teflon reference junction is easily replaced if it becomes fouled or plugged. The potassium-chloride-based reference electrolyte is a chemically inert viscous gel that is unaffected by thermal or pressure cycling. With the junction removed, the outer reference electrolyte can be recharged using a gel-filled syringe supplied in the various solutions kits available as an accessory. Replacing a clogged junction or recharging the electrolyte will rejuvenate most failed sensors. Proper preventative maintenance can dramatically extend the life of the sensor by minimizing the depletion or poisoning of the primary reference.

The available Solution Kits optimize the PERpH-X 3500 performance by keeping the porous Teflon reference from coating and the electrolyte from fouling. Six solutions are available as electrolyte kits: high-temperature; bio-film-resistant; poisoning-resistant; oil-resistant; scaling-resistant; metals-resistant. Each kit contains a treated porous Teflon reference junction and a specially formulated electrolyte to extend the life of the reference electrode in its targeted application.

In addition, the AccuGlass pH glass electrode provides exceptional resistance to thermal and caustic degradation, resulting in less breakage from thermal stress or shock and faster response rates for fast and accurate calibrations even after months of service. The PERpH-X 3500 provides near-theoretical response for pH measurement, even at extreme values, and minimal hysteresis, and is designed with a removable, slotted tip that protects the glass bulb from direct impacts while in service and during calibration. Further assuring the sensor can withstand the demanding environments present in harsh chemical processing applications, the sensor is also fitted with a molded Ryton body and EPDM, Viton or Kalrez o-rings.

The PERpH-X 3500 and 3500VP with Variopol connector is currently available for order.