This H-B Instrument® DURAC® API ASTM hydrometer conforms to the accuracy requirements for ASTM API Scale (American Petroleum Institute) hydrometers and is individually serialized. It features readings in 0.1 divisions and a metal ballast. Each hydrometer includes a multi-language (English, French, German, Italian, Portuguese, and Spanish) Statement of Accuracy indicating accuracy traceable to NIST and DKD/PTB. Tested and calibrated in an exclusive triple accredited/registered ISO/IEC 17025:2005, A2LA accredited laboratory against equipment whose calibration is traceable to NIST and DKD/PTB. Temperature of standardization 60°C/60°F. ASTM Number: 23H. Range: 10 to 16°. Divisions: 0.1°. Length: 163mm (6.4 Inches). Accuracy: 0.1°API. H-B Instrument® #: 23H.