N.J. Stat. § 51:9-4: Calculating volume by weight; tables for conversion of weight to volume and temperature corrections

If the volume be calculated by weight, the net weight shall be determined by means of a scale of approved type and capacity, tested and sealed by any weights and measures official. For the conversion of weight to volume and for temperature corrections, the National Standard Petroleum Oil Tables as approved by the United States Bureau of Standards shall be used.