N.J. Stat. Ann. § 51:1-91

No person shall alter or change in any manner any weight or measure, or allow the same to be done, after the same has been tested and sealed or tested and condemned by any weights and measures officer under authority of law, so that the same shall weigh or measure incorrectly, under a civil penalty of not less than $100.00 nor more than $500.00 for each offense, unless the person has been duly licensed and registered pursuant to the provisions of P.L. 1938, c. 182 (C. 51:1-113 et seq.). This section shall not prohibit any authorized person from making adjustments necessary to achieve zero balance on any weighing or measuring device.