Business and Professions Code § 12501
CHAPTER 5. Weighing and Measuring Devices
Except as provided in Section 12502 and, with respect to odometers, as is provided in Section 12501.1, every person who, for commercial purposes, sells weights or measures or weighing instruments or measuring instruments shall, within one year before selling the same, cause such weights or measures or weighing instruments or measuring instruments to be sealed by a sealer.