Sch 6 para 3 Maximum permissible error
(1) Where a cold-water meter is used for trade within a flowrate range set out in column 1 of the following Table, it must operate within the maximum permissible error specified for that flowrate range set out in column 2 of that Table. (2) For the purposes of that Table— (a) “Q 1 ” is the lowest flowrate at which the cold-water meter provides indications that satisfy the requirements concerning the maximum permissible errors; (b) “Q 2 ” is the flowrate value occurring between the permanent and minimum flowrates, at which the flowrate range is divided into two zones, the upper zone and the lower zone, each zone having a characteristic maximum permissible error; (c) “Q 3 ” is the permanent flowrate; and (d) “Q 4 ” is the highest flowrate at which the cold-water meter operates in a satisfactory manner.