Paragon Scientific's ISO 17025 / ISO 17034 dual certified Pure Water Viscosity Standards are certified in strict accordance with ASTM D445 for 5°C, as well as ASTM D2162, the primary method for viscosity standards manufacture, for temperatures at 20°C, 25°C and 37°C. Dual certified to the International Standards BS EN ISO / IEC 17025 and ISO 17034 under our UKAS accrediatation. We test at Primary level using master viscometers in accordance with ASTM D2162 to ensure the lowest uncertainty of measurement thus providing standards that are certified with primary level accuracy.