This chapter applies to farm milk tanks that are: Located on the premises of the producer; and Used, or to be used, under an express agreement between the producer and the purchaser for the commercial measurement of milk. This chapter does not apply to farm milk tanks that are mounted on highway vehicles. This chapter does not apply if a fluid meter is used for the commercial measurement of milk. In this situation, the specifications, tolerances, and requirements specified in the National Institute of Standards and Technology Handbook 44, Section 3.35, apply.