Cal. Bus. & Prof. Code § 12501.1
Every person who uses, or intends to use, any weight or measure, or weighing or measuring instrument for commercial purposes shall, before using the same, cause them to be sealed by a sealer, unless they have been sealed before sale, in which case they may be used by the purchaser for the remainder of such period as is authorized in the regulations adopted by the secretary pursuant to Section 12212, or until they become "incorrect," as defined in subdivision (d) of Section 12500.
Notwithstanding any other provision of law, an odometer that has been tested by the manufacturer may be used commercially without further test during the remainder of the inspection period adopted by the secretary for odometers, but shall not be used commercially thereafter until it has been sealed by a sealer.
Ca. Bus. and Prof'l. Code § 12501.1