Calibration Oils are one of the most commonly used materials for calibrating refractometers as they have good traceability, particularly to NIST. Having a high temperature co-efficient, calibration oils are used where strict temperature control is adopted, either by Peltier or external waterbath between 10 and 75 °C (from batches BSLP24 & BSDC17 onwards – previous batches between 20 and 75°C only). Calibration Oils are batch manufactured and so values may differ slightly from published data. Oils are supplied in multipacks of 5 x 5ml bottles with a certificate of calibration, MSDS and pipettes and have an expiry date 12-months from date of dispatch.