Sanitary pH sensor for food and pharmaceutical applications

A new sanitary pH sensor designed to minimise contamination in applications in the food and pharmaceutical industries has been introduced by Yokogawa Europe.

The new pH3A sensor has been developed by Pfaudler - a world leader in the technology of corrosion-resistant materials - in conjunction with Yokogawa and combines Pfaudler's unique enamelling technology with Yokogawa's extensive knowledge of pH measurement and electronics.

The new unbreakable sanitary pH3A sensor is designed for use in industries, of which food and pharmaceuticals are the most important, where conventional pH sensors cannot be used because of the risk of product contamination from broken glass.

The pH3A sanitary sensor combines the robustness of steel with the chemical resistance of Pfaudler PharmaGlass (PPG) coated enamel, which has been specifically developed to address the challenge of increasing the surface smoothness. By eliminating product build-up and reducing the need for cleaning, Pfaudler PharmaGlass minimises downtime and increases system productivity.

The high chemical resistance of the sensor makes it suitable for the CIP (cleaning in place) and SIP (sterilisation in place) cleaning regimes that are used in the food and pharmaceutical industries.

Pfaudler measuring probes can be used in applications where conventional pH electrodes are unsuitable because they do not comply with industry standard requirements including specifications laid down by the FDA, EHEDG and GMP.

The design of the pH3A overcomes these restrictions, and also offers a number of additional advantages. Unlike conventional glass electrodes, the pH sensitive enamel only makes contact with the fluids on the outside of the probe, making aging of the probe impossible. As no air bubble can be present on the inside, the probe can be mounted easily in any direction (even vertically) in most pipeline and vessel applications.

The diaphragm in the new sensor consists of a ground ceramic puck which is shrink-fitted into the end of the probe tube. The contact area between the ceramic puck and the ground glass surface forms the diaphragm gap, allowing electrolyte penetration to the product. The pressurised reference junction prevents the product and the electrolyte from mixing, making clogging and poisoning practically impossible.

The use of enamel glass, in combination with the pressurised reference junction, results in an extremely reliable and accurate measurement over the sensor's whole range of 0-10 pH. The Yokogawa pH instrumentation range offers the same extremely high reliability using modern electronics to ensure the best possible accuracy.

The combination of Pfaudler and Yokogawa technologies offers the user the best of both worlds: a rugged, versatile and dependable measuring system, with minimal maintenance and high integrity under even the most severe conditions.

The sensor is supplied with process adapters to fit industry standardprocess connections.

For more information about Yokogawa, please visit our web site at www.yokogawa.com

For more information contact:

Michelle Crowder
Yokogawa UK Limited
Stuart Road
Manor Park
Runcorn
CHESHIRE
WA7 1TR
Tel: +44 (0) 1928 597100
Fax: +44 (0) 1928 597101
Email: info@yokogawa.co.uk
http://www.yokogawa.com/eu