The Weighing Equipment (Non-automatic Weighing Machines) Regulations 1988

11.  The specifications for non-graduated and graduated Class I machines are given in Table 1.

Table 1

Maximum capacity “Max”	Lower limit of the minimum load “Min”	Scale interval “d”	Number of scale intervals “n”	Verification scale interval “e”
Notes 1. When a machine is provided with a rider its verification scale interval shall be the smaller of the following— (i) the verification scale interval of the machine not taking into account the rider, or (ii) the scale interval of the rider device. 2. When graduated machines of the self and semi-self indicating type are provided with a device for interpolation of reading, this shall not be taken into account when determining the verification scale interval of the machine. 3. When graduated machines of the self or semi-self indicating type are provided with an indicating device on which the last figure is clearly differentiated from the other figures, the verification scale interval shall correspond to the last but one figure of the indication. 4. In the case of machines where the weight indicating or printing is in carat (metric) units or units of the imperial system the relevant capacity and verification scale interval shall be the amounts in carat (metric) or imperial units respectively which are equivalent to those specified in the Table in terms of mg, g and kg. 5. Where the equivalent metric value for an imperial scale interval falls between ranges then the value shall be considered as belonging to the lower range.
Non-graduated machines
100 mg ≤ Max ≤ 1 g	10 e			0.1 mg
1 g < Max < 10 g	50 e
10 g ≤ Max < 100 g	50 e			1 mg
100 g ≤ Max	50 e
Graduated machines
0.5 mg ≤ Max	d	d ≤ 0.005 mg	10 ≤ n	d
1 mg ≤ Max	10 d	0.01 mg ≤ d ≤ 0.05 mg	100 ≤ n	d
10 mg ≤ Max	50 d	0.1 mg ≤ d ≤ 0.5 mg	100 ≤ n	d
100 g ≤ Max	50 d	1 mg ≤ d	100 000 ≤ n	d