The Weights and Measures Regulations 1963

83.—(1) In testing counter machines, the inspector shall satisfy himself—

(a) in the case of non-self-indicating machines, that the minimum movement of the beam from the horizontal in either direction is as follows:—

Capacity of machine	Minimum movement of beam from the horizontal
Not exceeding 4 pounds	¼ inch
Above 4 pounds and not exceeding 7 pounds	No math image to display inch
Above 7 pounds and not exceeding 28 pounds	⅜ inch
Above 28 pounds and not exceeding 56 pounds	No math image to display inch
Above 56 pounds	½ inch

(b) that, when the pans are loaded to half the capacity of the machine (the load being uniformly distributed) and the knife-edges or bearings are moved laterally or backwards and forwards within their limits of movement, there is no appreciable difference in the indications of weight shown by the instrument.

(2) When the goods pan is not in the form of a scoop, the machine shall indicate the same weight within half the prescribed limits of error if the centre of a load equal to half the capacity of the machine is placed on the goods pan anywhere within a distance from the centre equal to one-third of the greatest length of the pan, or, if the pan has a vertical side, against the middle of that side; the load on the weights pan being entirely on that pan but in any position on it.

(3) Where the goods pan is in the form of a scoop, the machine shall fall within the prescribed limits of error when a load equal to half the capacity of the machine is placed against the middle of the back of the scoop and again when a like load is placed in any position on the scoop; the load on the weights pan being entirely on that pan but in any position on it.