For metric density, ASTM 321H covers the range from 775 to 825 kg/m³, avoiding the need to purchase two hydrometers, ASTM 314H & 315H.

Please note if you require a Certified Hydrometer with a Certificate of Calibration, there is an extra cost for this service. You must make your requirement known by ADDING a Certificate of Calibration for each Hydrometer that you need calibrated to your order. Also there is a three to four week lead time added to your order.