API MPMS 4.9.4 : 2010 Title: Manual of Petroleum Measurement Standards Chapter 4—Proving Systems Section 9—Methods of Calibration for Displacement and Volumetric Tank Provers Part 4—Determination of the Volume of Displacement and Tank Provers by the Gravimetric Method of Calibration Year: 2010 Publisher: The American Petroleum Institute Availability: Within 1-2 working days