
1 

(1) These Regulations may be cited as the Weights and Measures (Local and Working Standard Weights and Testing Equipment) Regulations 1986 and shall come into operation on 1st November 1986.
(2) The Weights and Measures (Local and Working Standard Weights and Testing Equipment) Regulations 1983 are hereby revoked.
2 

(1) In these Regulations—
 “analogue” means capable of assigning any value or position within a continuous range;
 “digital” means capable of assigning only certain discrete values or positions within a continuous range by a series of discontinuous steps;
 “discrimination threshold” means, in the case of testing equipment with a digital indicator, the weight which produces a change of reading of one digit from one change point to the next change point, and in the case of testing equipment with an analogue indicator, the weight which produces a 1 millimetre apparent movement of the pointer;
 “non-automatic weighing machine” means a machine which requires the intervention of an operator during the weighing process, especially to deposit loads on, or remove loads from, the part of the machine on which loads are placed for the purpose of their being weighed and to determine the result of the weighing process;
 “repeatability” means the ability of weighing equipment to indicate, under defined conditions of use, closely similar quantities on repeated weighings; and
 “95 per cent. confidence interval” means the range of values within which the true value may be expected to lie with a 0.95 level of probability.
(2) The symbols for, and abbreviations of, units of weight used in these Regulations refer to the relevant units set out in Schedule 1 to these Regulations.
3 

(1) Working standard weights and test weights and egg grading machine test poises shall have been tested within twelve months before use and, where an inspector has reasonable cause to believe that any such weight or poise is not accurate within the relevant limit of error, he shall test it before use.
(2) Where a test reveals an error exceeding the relevant limit of error the weight or poise shall not be further used until it has been so adjusted that any error is within that limit.
4 
Working standard weights shall be tested against local standard weights by the method of substitution.
5 
Test weights and egg grading machine test poises shall be tested by either:
(a) the method of substitution, or
(b) the method of comparison against either:
(i) local standard weights; or
(ii) working standard weights or test weights,provided that in the opinion of the inspector the necessary accuracy can be achieved.
6 

(1) Testing equipment consisting of weighing equipment shall have been tested for repeatability and for discrimination threshold within six months before use and shall not be used for testing working standard weights, test weights or egg grading machine test poises unless it complies with the requirements of Regulation 7 below.
(2) Where an inspector has reasonable cause to believe that any testing equipment referred to in this Regulation is not accurate within the relevant limit of error, he shall test it before use.
7 
Testing equipment consisting of weighing equipment used for testing working standard weights, test weights and egg grading machine test poises shall comply with the following requirements:
(a) the discrimination threshold of the testing equipment used shall not exceed one-fifth of the relevant amount specified in Tables 1 to 6 in Schedule 2 to these Regulations as the limit of error for the weight being tested, or, in the case of an egg grading machine test poise, 7 mg, and
(b) the repeatability of the testing equipment shall be such that the 95 per cent. confidence interval of a single reading does not exceed one-fifth of the relevant amount specified in Tables 1 to 6 in Schedule 2 to these Regulations as the limit of error for the weight being tested, or, in the case of an egg grading machine test poise, 7 mg.
8 

(1) The prescribed limits of error relating to local and working standard weights and test weights shall be those set out in Tables 1 to 6 in Schedule 2 to these Regulations.
(2) The prescribed limit of error relating to egg grading machine test poises shall be 35 mg.
9 
The period of five years is hereby prescribed in the case of a weight for the purpose of section 4(6) of the Act (which relates to periods of validity of certificates of fitness of local standards) running from the date of issue of the certificate.
Michael Howard
Parliamentary Under-Secretary of State
Department of Trade and Industry
29th September 1986
SCHEDULE 1
Regulation 2


Symbols and abbreviations of units of weight
Imperial Metric
pound lb kilogram kg
ounce oz gram g
  milligram mg
  carat (metric) C.M.
SCHEDULE 2
Regulations 7, 8

TABLE 1
 Limit of error in milligrams
Local or working standards of— Local standard Working standard
56 lb 400 1250
28 lb 200 650
14 lb 100 320
7 lb 50 160
4 lb 30 90
2 lb 15 45
1 lb 7 20
8 oz 3 10
4 oz 2 6
2 oz 1 3
1 oz 0.8 2.5
1/2 oz 0.7 2
1/4 oz 0.5 1.5
1/8 oz 0.5 1.5
1/16 oz 0.4 1.2
1/32 oz 0.3 1
50 lb 350 1100
20 lb 150 450
10 lb 70 220
5 lb 35 110

TABLE 2
Local standard of— Limit of error in milligrams
100 0.53
50 0.44
30 0.40
20 0.33
10 0.27
5 0.22
3 0.20
2 0.17
1 0.13
0.5 0.11
0.3 0.10
0.2 0.09
0.1 0.06
0.05 0.06
0.03 0.06
0.02 0.06
0.01 0.06

TABLE 3
Local standard of ounces troy— Limit of error in milligrams
500 250
400 200
300 150
200 100
100 50
50 25
40 20
30 15
20 10
10 5
5 2.5
4 2.0
3 1.5
2 1.0
1 1.0
0.5 0.7
0.4 0.6
0.3 0.6
0.2 0.5
0.1 0.4
0.05 0.4
0.04 0.3
0.03 0.3
0.025 0.3
0.02 0.25
0.01 0.22
0.005 0.18
0.004 0.16
0.003 0.15
0.002 0.13
0.001 0.11

TABLE 4
 Limit of error in milligrams
Local or working standards of— Local standard Working standard
20 kg 300 1000
10 kg 150 500
5 kg 75 250
2 kg 30 100
1 kg 15 50
500 g 7.5 25
200 g 3.0 10
100 g 1.5 5
50 g 1.0 3
20 g 0.8 2.5
15 g 0.7 2.2
10 g 0.6 2.0
5 g 0.5 1.5
4 g 0.5 1.5
3 g 0.4 1.2
2 g 0.4 1.2
1 g 0.3 1.0
500 mg 0.25 0.8
400 mg 0.25 0.8
300 mg 0.25 0.8
200 mg 0.20 0.6
150 mg 0.20 0.6
100 mg 0.15 0.5
50 mg 0.12 0.4
20 mg 0.10 0.3
10 mg 0.08 0.25
5 mg 0.06 0.20
2 mg 0.06 0.20
1 mg 0.06 0.20

TABLE 5
Local standard of— C.M. Limit of error in milligrams
500 1.5
200 0.93
100 0.80
50 0.60
20 0.47
10 0.40
5 0.30
2 0.23
1 0.20
0.5 0.15
0.25 0.12
0.20 0.11
0.10 0.10
0.05 0.08
0.02 0.06
0.01 0.06

TABLE 6
Imperial weight Limit of error Metric weight Limit of error
11200 lb 500 g
4480 lb 200 g 5000 kg 500 g
2240 lb 100 g 2000 kg 200 g
1120 lb 50 g 1000 kg 100 g
1008 lb 50 g 500 kg 50 g
560 lb 20 g 250 kg 20 g
448 lb 20 g 200 kg 20 g
224 lb 10 g 100 kg 10 g
112 lb 5 g 50 kg 5 g