Draft Survey Hydrometer – Overview This Draft Survey Hydrometer is suitable for use in sea or freshwater. A draft survey is a method of cargo weight measurement where the vessel’s water levels are taken when empty and again when loaded. The difference between the two determines the weight of the shipment loaded (or unloaded). Draft Survey Hydrometer – Features Highest quality glass tubing Clearly marked figures and graduations on scales Temperature adjustment indicated Fiducial Mark (datum line) enables calibration by UKAS Laboratories where applicable
