Retractable sensor fitting

Yokogawa has developed a retractable sensor fitting that offers a flexible approach to online liquid analytical measurements in a wide range of process industries.

The Yokogawa PR10 has been designed for online process applications where the sensor has to be removed safely without interrupting process continuity - in anaerobic, toxic or pressurised environments, for example. The device is suited to pH, ORP, conductivity, inductive conductivity and dissolved oxygen measurements.

The unit is available with a wide range of adapters, ball valves and flanges, and the insertion depth can be adjusted to achieve optimum measurement conditions. Total disassembly without interruption to the process is possible when the ball valve is closed, and safe retraction is possible at pressures up to 5 barg.

For ease of maintenance, a scraper is built in, and maintenance time is further reduced because fewer O-rings are needed for a good process seal. An optional flush port makes it easy to keep pH and dissolved oxygen sensors moist and clean, and also provides access for calibration.

The device will accommodate most commercially available pH electrodes with PG 13.5 mm thread or DIN connections, as well as Yokogawa’s SC4A conductivity and ISC40 inductive conductivity sensors (with a built-in protection cage for the latter).

For dissolved oxygen measurements, the Yokogawa-Hamilton Visiferm, Oxyferm and Oxygold sensors can be installed. These sensors are typically used in nitrogen blanketing applications, where the optional flush port will allow regular moisturising of the sensor to prevent the membrane from drying out.

The device is suitable for applications such as: the chemical industry, power plants, pulp and paper manufacture, water and effluent treatment, pharmaceuticals and the semiconductor industry.