The Weights and Measures Regulations 1963

PART VI ALL WEIGHING INSTRUMENTS

57.  Notwithstanding anything contained in Parts VII to XIV relating to weighing instruments of a particular type, class or description, the provisions of this Part of these Regulations shall have effect in relation to all weighing instruments to which these Regulations apply.

58.—(1) New weighing instruments shall have their maker's name and their capacity conspicuously, legibly and durably marked thereon.

(2) Where units of measurement are marked on weighing instruments, they shall be marked either in full or by means of one of the following abbreviations only:—

• cwt

• ctl

• qr

• lb

• oz

• dr

• gr

• oz.tr

• dwt

• oz.apoth

• kg

• kilogram

• kilog

• g

• gram

• grm

• mg

• milligram

• C.M.

Materials and principles of construction

59.  All knife-edges and bearings in weighing instruments shall be of hard steel or agate or of other material approved by the Board; they shall be so fitted as to allow the beam or steelyard indicator to move easily, and the knife-edges shall substantially near upon the whole length of their working parts.

60.—(1) All removable counterpoises weighing 1 ounce or more and all sliding poises on weighing instruments, shall contain an undercut adjusting hole or other means of adjustment.

(2) Any loose material used in any such counterpoise or poise shall be securely enclosed therein.

61.  Weighing instruments with removable parts, the removal of which would affect their accuracy, shall be so construed that they cannot be used if any of the said parts are removed.

62.  Where weighing instruments have interchangeable or reversible parts, the interchange or reversal thereof shall not affect the accuracy of the instrument.

63.  All graduations on weighing instruments shall be so defined that the positions of all sliding poises or indicators are clearly readable.

Testing

64.—(1) Subject to paragraph (2) of this regulation, in testing any weighing instrument, the inspector shall satisfy himself that—

(a) it is properly balanced when unloaded;

(b) the beam (if any) has sufficient, room for oscillation and returns to the position of equilibrium when the load is removed;

(c) the indicator (if any) returns to the zero mark or minimum graduation when the load is removed.

(2) Paragraph 1(a) of this regulation shall not apply in the case of a weighing instrument of a pattern in respect of which a certificate of approval granted or deemed to have been granted under section 12 of the Weights and Measures Act 1963 is in force, if such an instrument is not so constructed as to balance when unloaded.

65.  Movable weighing instruments provided with a base shall be tested on a level plane.

66.  Weighing instruments which are designed to be suspended when in use shall be suspended during testing.

67.—(1) Weighing instruments used in any of the following transactions, that is to say, transactions—

(a) in gold, silver or other precious metals,

(b) in precious stones,

(c) in jewellery,

(d) in silk,

(e) by retail in drugs or other pharmaceutical products,

shall either—

(i) be balances, or

(ii) being instruments other than balances, fall within the prescribed limits of error for beam scales marked “Class B”.

(2) Weighing instruments used in retail transactions in tobacco shall either—

(a) be balances, or

(b) being instruments other than balances, fall within the prescribed limits of error for beam scales marked “Class B” or “Class C”.

68.—(1) Unless otherwise provided in these Regulations, vibrating weighing instruments shall be tested for sensitiveness by loading the instrument with the maximum testing load (or as near thereto as, in the opinion of the inspector, circumstances permit) with the beam or steelyard indicator in a horizontal position, and ascertaining that it moves with the addition of the weight to be added to test sensitiveness as specified in Parts II, III, V, VI, VII, IX or X, as the case may be, of Schedule 2 hereto. No test for sensitiveness at a lower load shall be made.

(2) In the case of beam scales and balances, the addition of the said weight to either pan shall cause an appreciable movement of the beam.

(3) In the case of vibrating weighing instruments other than beam scales or balances, the addition of the said weight shall cause the beam or steelyard indicator to rise or fall to the limit of its range of movement.

69.  Vibrating weighing instruments shall be tested for error by ascertaining the weight to be added thereto or removed therefrom, in order to bring the beam or steelyard indicator of the instrument to a horizontal position when the instrument is loaded with the maximum testing load (or as near thereto as, in the opinion of the inspector, circumstances permit).

70.  Accelerating weighing instruments shall be tested for error by ascertaining the weight required just to keep the beam or steelyard indicator in a horizontal position on its stop or carrier and no more; and shall be further tested by ascertaining the weight required to bring back the beam or steelyard indicator from its position of greatest displacement to the horizontal position, the instrument being at all times fully loaded and truly balanced.

71.  In testing weighing instruments fitted with a price computing mechanism, the inspector shall in addition to testing at each numbered graduation satisfy himself that—

(a) they indicate the price correctly; and

(b) they comply with the requirements of these Regulations in so far as they are applicable to the particular type, class or description of weighing instrument concerned.