As used in this chapter the following terms mean:
"Commercial purposes" do not include the determination of the weight, measure, or count of any commodity or thing that is performed within a plant or business as a part of the manufacturing, processing, or preparing for market of that commodity or thing, or the determination of charges for the transmission of letters or parcels of less than 150 pounds, except when that determination is made in the presence of the customer charged for the service, or the determination of the weight of any animal or human by a qualified health provider, California-licensed veterinarian, licensed physician and surgeon, or staff members within the business operations of, and under the supervision of, a California-licensed veterinarian or licensed physician and surgeon for the purposes of determining the appropriate dosage of any medication or medical treatment or the volume, duration, or application of any medical procedure.
Ca. Bus. and Prof'l. Code § 12500