The Flexim PIOX R721 R is the chemical design variant of the process refractometer and offers as a fully stainless-steel design variant with all wetted materials made out of grade 316 Ti / 1.4571 steel. When dealing with highly corrosive media, such as hydrochloric, strong sulfuric or hydrofluoric acid, the PIOX R inline refractometer is also available as a special carbon reinforced PTFE design variant offering an unrivalled corrosion resistance, long term stability and reliability in such harsh environments. Being FM Class I Div. 2 / Class I Div. 1 certified and available with long and short sensor heads that can be integrated into the process via DIN / ANSI flange.