Weights and Measures


Agricultural Commissioner/Sealer of Weights and Measures

Greg Clark, Agricultural Commissioner Sealer of Weights and Measures

Weights and Measures

Weights and Measures Building Sign

The mission of the Napa County Department of Weights and Measures is to provide fair competition and equity in the marketplace and to ensure that the interests of the buyer and seller are protected through educational, inspection and enforcement programs. 

Under the authority of the Secretary of the California Department of Food and Agriculture (CDFA), each County has an appointed Sealer who is responsible for the enforcement of California Weights and Measures laws and regulations. In Napa County, this function is administered by the Agricultural Commissioner/Sealer’s Office. The Napa County Department of Weights and Measures is divided into several programs to: 

  • ensure the accuracy of commercial weighing and measuring devices
  • verify the price, quantity and labeling of packaged and bulk commodities
  • verify quality, advertising and labeling standards for various petroleum products
  • enforce Weighmaster laws to assure accuracy of information on Weighmaster certificates.


     Enjoy this Informative video to see how Weights and Measures protects consumers, workers, and businesses.  

     Learn more here


Quantity Control of Packaged Goods  

Weighing and Measuring Device Registration

Weighmaster Enforcement Program

Buying Commercial Scales on the Internet (.pdf)

Weighing and Measuring Device Registration ordinance (.pdf)

Annual State Device Administrative Fee Chart (.pdf)

Weights and Measures informational brochure (.pdf)

Registered Service Agent Examination: Anyone wishing to take the RSA exam on or After April 1, 2013 must take the test online at DMS Registered Service Agency (select Registered Service Agent Online Exam link on the right- hand side of the page)


Helpful Links:

California Division of Measurement Standards

     DMS programs:   

California Department of Consumer Affairs  /Protects and serves California consumers while ensuring a competent and fair marketplace.
California Association of Standards and Agricultural Professionals /Staff association dedicated to promoting professionalism in county government.
California Public Utilities Commission /Regulates privately owned telecommunications, electric, natural gas, water, railroad, rail transit, and passenger transportation companies.
National Institute of Standards and Technology ( NIST ) /Formerly the National Bureau of Standards. Establishes the scientific validity of standards.
National Conference on Weights & Measures /Industry and government officials developing operational regulatory standards.