Wash. Rev. Code § 19.94.150
The system of weights and measures in customary use in the United States and the metric system of weights and measures are jointly recognized, and either one or both of these systems shall be used for all commercial purposes in this state. The definitions of basic units of weight and measure and weights and measures equivalents, as published by the national institute of standards and technology or any successor organization, are recognized and shall govern weighing or measuring instruments or devices used in commercial activities and other transactions involving weights and measures within this state.
RCW 19.94.150
Legislative findings-1991 sp.s. c 23: "The legislature finds:
(1) Accurate weights and measures are essential for the efficient operation of commerce in Washington, and weights and measures are important to both consumers and businesses.
(2) Legislation to expand the weights and measures program and fund the program with license fees on weights and measures devices has been considered.
(3) Additional information is necessary before further action can be taken." [ 1991 sp.s. c 23 s 1.]
Intent-1991 sp.s. c 23: "It is the intent of the legislature to fund the current weights and measures program only through the first year of the 1991-93 fiscal biennium, and to base funding of the program for the second year of the biennium and ensuing biennia upon the recommendations of the study performed under section 3, chapter 23, Laws of 1991 sp. sess." [ 1991 sp.s. c 23 s 2.]