Saunders® body refractometer PR‑23‑W is a heavy-duty instrument designed for chemically aggressive liquids and ultra-pure fine chemicals in large-scale production and in large pipelines. The materials and design of the sensor are similar to the Teflon® body refractometer PR‑23‑M, but the Saunders® body makes it possible to fit this refractometer into 50 mm, 80 mm or 100 mm (2 in, 3 in or 4 in) pipelines.
Saunders® body material is graphite cast iron lined with 3 mm PFA (fluorinated ethylene propylene) or ETFE (ethylene tetrafluoroethylene) fluoroplastic. The cast iron provides a solid mechanical base and the PFA/ETFE lining ensures the chemical resistance.
The sensor itself is built just like the PR‑23‑M sensor, see Teflon body refractometer PR‑23‑M/MS, and it is fixed to the Saunders® body in the same way, with a sapphire plate and a Kalrez® O‑ring to keep all the metallic parts away from the process liquid.