Despite the principles of measuring the refractive index (RI) of a solution dating back to the mid nineteenth Century, modern-day refractometers continue to play an important role in industry today, from chemical processing to pharmaceutical to automotive. As instruments get more sophisticated, they become more capable of measuring to higher accuracies, especially now that on-board temperature control is facilitated by intelligently controlled Peltier devices.
One such application that is taking advantage of refractometer technology is within the chemical industry at a PVA monomer plant, where direct readout of sample concentration is simply displayed on the latest color display making interpretation by non-skilled operators far easier than before. The user defined scale (UDS) capability incorporated to the latest Bellingham + Stanley RFM340+ refractometer has provided efficient solutions where correlation between refractive index and the solids content of a PVA adhesive was established. This solution not only enabled the overall analysis time to be reduced significantly, but the level of operator skill and associated risk of error was diminished as well.
In another chemical processing application, the UDS capability on the refractometer also enabled the correlation of polymer solids to RI, to eliminate lengthy non-volatile solids testing and ultimately reducing costs in the process.
Likewise, within a pharmaceutical industry application, a major European influenza vaccine producer turned to Bellingham + Stanley to provide replacement refractometers for their production plant. Due to the strict hygiene regulatory needs dictated by FDA regulation, special materials were applied to the wetted areas of the instrument, including PEEK sample presser, Kalrez® gasket materials and high grade stainless steel prism dish that was traceable in accordance with ISO 10204. The customer had utilized Bellingham + Stanley solutions for one of their previous instrument requirements, with great success, again with special materials fitted to the wetted areas in compliance with latest FDA regulations. Additionally, they had recently purchased a considerable number of PRH on-line refractometers for use at their facility in Dresden, Germany that is responsible for producing bird-flu vaccine.