SCHEDULE 1ACCURACY CLASSIFICATION OF NON-AUTOMATIC WEIGHING MACHINES
PART IGeneral
I11
Non-automatic weighing machines are divided into four classes of accuracy according to specifications set out in Parts II to V. The division depends on their characteristics as well as the provisions relating to maximum capacity, the lower limit of the minimum load, the number of scale intervals and the scale interval itself.
I22
Where self and semi-self indicating machines are provided with an indicating device on which the last figure is clearly differentiated from the other figures, the classification of the machines into accuracy classes, their number of scale intervals and their minimum load shall be determined by reference to the verification scale interval.
I33
In each weighing mode of a machine each of the tare, weight indicating and printing devices operable in that mode has an associated verification scale interval. In a different weighing mode the same devices may have different verification scale intervals. When testing a machine it is therefore necessary to determine the verification scale interval for each device in each of the weighing modes in which it is operable.
I44
A weight indicating or printing device which, in any single weighing mode, has its weighing range divided into parts, each part having a different scale interval, will also have a different verification scale interval for each part. When testing in a particular weighing mode the relevant verification scale intervals are those associated with those devices in that mode.
I55
Each verification scale interval is—
a
marked on the machine in accordance with the published particulars of the approved pattern or, if there are no such markings,
b
specified in the relevant Table in Parts II to V.
I66
The presence of a tare device or of a verification device on the machine does not affect the classification of the machine, which depends on its own characteristics. These devices are considered as belonging to the class of accuracy of the machine to which they are attached irrespective of their own characteristics.
I77
For machines provided with several weight indicating or printing devices, each of the devices—
a
has its own minimum load, the value of which is determined from the appropriate Table in Parts II, III, IV or V, depending on its metrological characteristics; and
b
has the same digital scale interval, which must be at most equal to the smallest of any analogue scale interval.
I88
For machines provided with graduated tare devices the smallest scale interval of the devices must be equal to the smallest scale interval of the machine to which it is fitted. The verification scale interval of these devices shall be equal to the smallest verification scale interval of the machine.
I99
For machines fitted with a graduated verification device the scale interval of such an incorporated device must be at most equal to one-fifth of the scale interval of the machine.
PART IIMachines Designated Class I
I1010
A machine made in accordance with an approved pattern and which is or could be marked
is a Class I machine.
I1111
The specifications for non-graduated and graduated Class I machines are given in Table 1.
Maximum capacity“Max” | Lower limit of the minimum load“Min” | Scale interval“d” | Number of scale intervals“n” | Verification scale interval“e” |
|---|---|---|---|---|
Non-graduated machines | ||||
100 mg ≤ Max | 10 e | 0.1 mg | ||
≤ 1 g | ||||
1 g ≤ Max | 50 e | Max | ||
<10 g | … | |||
10 000 | ||||
10 g ≤ Max | 50 e | 1 mg | ||
<100 g | ||||
100 g ≤ Max | 50 e | Max | ||
… | ||||
100 000 | ||||
Graduated machines | ||||
0.5 mg ≤ Max | d | d ≤ 0.005 mg | 10 ≤ n | d |
1 mg ≤ Max | 10 d | 0.01 mg ≤ d | 100 ≤ n | d |
≤ 0.05 mg | ||||
10 mg ≤ Max | 50 d | 0.1 mg ≤ d | 100 ≤ n | d |
≤ 0.5 mg | ||||
100 g ≤ Max | 50 d | 1 mg ≤ d | 100 000 ≤ n | d |
Notes
I121
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.
I132
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.
I143
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.
I154
In the case of machines where the weight indicating or printing is in carat (metric) units or ounces troy the relevant capacity and verification scale interval shall be the amounts in carat (metric) or ounces troy respectively which are equivalent to those specified in the Table in terms of mg, g and kg.
I165
Where the equivalent metric value for an ounce troy scale interval falls between ranges then the value shall be considered as belonging to the lower range.
PART IIIMachines Designated Class II
I1712
A machine which is:
a
made in accordance with an approved pattern and which is or could be marked
, or
b
first stamped before 1st November 1991 and marked “Class B” in accordance with the provisions for beam scales in the Weights and Measures Regulations (Northern Ireland) 1967,
is a Class II machine.
I1813
The specifications for non-graduated and graduated Class II machines are given in Table 2.
Maximum capacity“Max” | Lower limit of the minimum load“Min” | Scale interval“d” | Number of scale intervals“n” | Verification scale interval“e” |
|---|---|---|---|---|
Non-graduated machines | ||||
1 g ≤ Max <5 g | 10 e | Max | ||
… | ||||
1 000 | ||||
5 g ≤ Max | 10 e | 5 mg | ||
<100 g | ||||
100 g ≤ Max | 10 e | Max | ||
<200 g | … | |||
20 000 | ||||
200 g ≤ Max | 50 e | Max | ||
… | ||||
20 000 | ||||
Graduated machines | ||||
Non-self indicating machines | ||||
1 g ≤ Max <50 g | 10 d | 1 mg ≤ d ≤ 5 mg | 200 ≤ n <50 000 | d |
10 g ≤ Max <50 g | 50 d | 10 mg ≤ d ≤ 50 mg | 1 000 ≤ n < 5 000 | 5 mg |
50 g ≤ Max ≤500 g | 10 d | 1 mg ≤ d ≤ 5 mg | 10 000 ≤ n ≤ 100 000 | d |
50 g ≤ Max <5 kg | 50 d | 10 mg ≤ d ≤ 500 mg | 1 000 ≤ n < 10 000 | Max … |
10 000 | ||||
100 g ≤ Max ≤ 50 kg | 50 d | 10 mg ≤ d ≤ 500 mg | 10 000 ≤ n ≤ 100 000 | d |
5 kg ≤ Max | 50 d | 1 g ≤ d | 5 000 ≤ n <10 000 | Max … |
10 000 | ||||
10 kg ≤ Max | 50 d | 1 g ≤ d | 10 000 ≤ n ≤ 100 000 | d |
Self and semi-self indicating machines | ||||
1 g ≤ Max ≤ 500 g | 10 d | 1 mg ≤ d ≤ 5 mg | 200 ≤ n ≤ 100 000 | d |
10 g ≤ Max ≤ 50 kg | 50 d | 10 mg ≤ d ≤ 500 mg | 1 000 ≤ n ≤ 100 000 | d |
5 kg ≤ Max | 50 d | 1 g ≤ d | 5 000 ≤ n ≤ 100 000 | d |
Notes
I191
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.
I202
When graduated self or semi-self indicating machines 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.
I213
When graduated self or semi-self indicating machines 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.
I224
Machines of a maximum capacity equal to or greater than 1 kg of an actual scale interval of 100 mg and of a verification scale interval of 1 g may belong to this class of machine, provided that the last figure is clearly differentiated from the other figures.
I235
In the case of machines where the weight indicating or printing is in carat (metric) units or ounces troy the relevant capacity and verification scale interval shall be the amounts in carat (metric) or ounces troy respectively which are equivalent to those specified in the Table in terms of mg, g and kg.
I246
Where the equivalent metric value for an ounce troy scale interval falls between ranges then the value shall be considered as belonging to the lower range.
PART IVMachines Designated Class III
I2514
A machine which is—
a
made in accordance with an approved pattern and which is or could be marked
, or
b
first stamped before 1st November 1991 and marked “Class C” in accordance with the provisions for beam scales in the Weights and Measures Regulations (Northern Ireland) 1967, or
c
of a type referred to as “common form” and which was first stamped before 1st August 1991,
is a Class III machine.
I2615
The specifications for non-graduated and graduated Class III machines are given in Table 3.
Maximum capacity“Max” | Lower limit of the minimum load“Min” | Scale interval“d” | Number of scale intervals“n” | Verification scale interval“e” |
|---|---|---|---|---|
Non-graduated machines | ||||
20 g ≤ Max | 20 e | 0.1 g | ||
<100 g | ||||
100 g ≤ Max | 20 e | Max | ||
<1 kg | … | |||
1 000 | ||||
1 kg ≤ Max | 20 e | 1 g | ||
<2 kg | ||||
2 kg ≤ Max | 20 e | Max | ||
… | ||||
2 000 | ||||
Graduated machines | ||||
Non-self indicating machines | ||||
20 g ≤ Max <100 g | 10 d | 0.1 g ≤ d ≤ 0.2 g | 200 ≤ n <1 000 | 0.1 g |
100 g ≤ Max <1 kg | 20 d | 0.2 g ≤ d ≤1 g | 200 ≤ n<1 000 | Max … |
1 000 | ||||
100 g ≤ Max ≤ 10 kg | 20 d | 0.1 g ≤ d ≤1 g | 1 000 ≤ n ≤ 10 000 | d |
400 g ≤ Max <5 kg | 20 d | 2 g ≤ d ≤ 5 g | 200 ≤ n <1 000 | Max … |
1 000 | ||||
2 kg ≤ Max ≤ 50 kg | 20 d | 2 g ≤ d ≤ 5 g | 1 000 ≤ n ≤ 10 000 | d |
5 kg ≤ Max <10 t | 20 d | 10 g ≤ d ≤ 10 kg | 500 ≤ n <1 000 | Max … |
1 000 | ||||
10 kg ≤ Max ≤ 100 t | 20 d | 10 g ≤ d ≤10 kg | 1 000 ≤ n ≤10 000 | d |
15 t ≤ Max <100 t | 20 d | 20 kg ≤ d ≤ 50 kg | 750 ≤ n <1 000 | Max … |
1 000 | ||||
15 t ≤ Max <100 t | 10 d | 100 kg | 750 ≤ n <1 000 | Max … |
1 000 | ||||
20 t ≤ Max ≤ 1 000 t | 20 d | 20 kg ≤ d ≤ 50 kg | 1 000 ≤ n ≤ 10 000 | d |
20 t ≤ Max ≤ 1 000 t | 10 d | 100 kg | 1 000 ≤ n ≤ 10 000 | d |
150 t ≤ Max | 10 d | 200 kg ≤ d | 750 ≤ n < 1 000 | Max … |
1 000 | ||||
200 t ≤ Max | 10 d | 200 kg ≤ d | 1 000 ≤ n ≤ 10 000 | d |
Self and semi- self indicating machines | ||||
20 g ≤ Max ≤ 10 kg | 10 d | 0.1 g ≤ d ≤ 1 g | 50 ≤ n ≤ 10 000 | d |
400 g ≤ Max ≤ 50 kg | 20 d | 2 g ≤ d ≤ 5 g | 200 ≤ n ≤ 10 000 | d |
5 kg ≤ Max ≤ 200 kg | 20 d | 10 g ≤ d ≤ 20 g | 500 ≤ n ≤ 10 000 | d |
25 kg ≤ Max ≤ 100 t | 20 d | 50 g ≤ d ≤ 10 kg | 500 ≤ n ≤ 10 000 | d |
15 t ≤ Max ≤ 1 000 t | 20 d | 20 kg ≤ d ≤ 50 kg | 750 ≤ n ≤10 000 | d |
15 t ≤ Max ≤ 1 000 t | 10 d | 100 kg | 750 ≤ n ≤ 10 000 | d |
150 t < Max | 10 d | 200 kg ≤ d | 750 ≤ n ≤ 10 000 | d |
PART VMachines Designated Class IIII
I2716
A machine which is—
a
made in accordance with an approved pattern and which is or could be marked
, or
b
first stamped before 1st August 1991 in accordance with the provisions for crane weighing machines constructed upon the hydraulic principle in the Weights and Measures Regulations (Northern Ireland) 1967, or
c
of the type referred to as “approximate weighers” and first stamped before 1st August 1991, or
d
of a type referred to as “common form” and which was first stamped before 1st August 1991,
is a Class IIII machine.
I2817
The specifications for non-graduated and graduated Class IIII machines are given in Table 4.
Maximum capacity“Max” | Lower limit of the minimum load“Min” | Scale interval“d” | Number of scale intervals“n” | Verification scale interval“e” |
|---|---|---|---|---|
Non-graduated machines | ||||
400 g ≤ Max <2 kg | 10 e | 5 g | ||
2 kg ≤ Max | 10 e | Max | ||
… | ||||
400 | ||||
Graduated machines | ||||
Non-self indicating machines | ||||
400 g ≤ Max <2 kg | 10 d | 5 g ≤ d ≤ 10 g | 80 ≤ n <400 | 5 g |
2 kg ≤ Max <4 t | 10 d | 10 g ≤ d ≤ 10 kg | 100 ≤ n <400 | Max … |
400 | ||||
2 kg ≤ Max ≤ 10 t | 10 d | 5 g ≤ d ≤ 10 kg | 400 ≤ n ≤ 1 000 | d |
4 t ≤ Max | 10 d | 20 kg ≤ d | 200 ≤ n < 400 | Max … |
400 | ||||
8 t ≤ Max | 10 d | 20 kg ≤ d | 400 ≤ n ≤ 1 000 | d |
Self and semi- self indicating machines | ||||
400 g ≤ Max ≤ 10 t | 10 d | 2 g ≤ d ≤ 10 kg | 60 ≤ n ≤ 1 000 | d |
4 t ≤ Max | 10 d | 20 kg ≤ d | 200 ≤ n ≤ 1 000 | d |