For refractometer performance verification, traceable to NIST/ICUMSA
Calibration Oils from Bellingham + Stanley come in boxes of 5. They are organic compounds that cover the range 1.47 -1.56 Refractive Index and cover the top end of the Brix scale. These Calibration Oils have a shelf-life of 12-months. They are ideal for calibrating refractometers that have temperature control in both food and industrial applications.