Sch 6 para 4 Maximum permissible error
(1) Where a cold water meter is marked with— (a) a temperature range, it must not be used for trade in temperatures outside that range; or (b) a flowrate range, it must not be used at a flowrate outside that range. (2) Where a cold-water meter bears a mark which signifies the manner and purposes of use, it must not be used for trade in a manner or for a purpose which does not accord with that marking. (3) A cold water meter must not be used for trade in circumstances— (a) in which it may be prevented from operating consistently or accurately; or (b) which are likely prematurely to degrade its metrological characteristics. (4) A cold-water meter must not be used for trade unless, when adjusted, the calibration of the instrument is set as close to zero as practicable.