Any person engaged in the business of the sale of oil at retail shall use a standard liquid measure, which measure shall not be a larger capacity than the amount of the purchase by any purchaser; provided, however, that this section shall not prevent the use of a correct liquid-measuring device when so located and disposed as to be clearly visible to and readable by the customer from any position which he may reasonably be expected to assume.
Ala. Code § 8-16-105 (1975)