Each utility shall maintain test records for each meter, which shall include the following: The date and reason for the test; The reading of the meter before making the test; The accuracy “as found” at each rate of flow; and The accuracy “as left” at each rate of flow. If the test of the meter is made by using a standard meter, then the utility shall retain all data taken at the time of the test in sufficiently complete form to permit the convenient checking of the test methods and the calculations.