Last Updated: 1 December 2016
[NTM 11,090] SCHEDULE 2 MAXIMUM PERMISSIBLE ERRORS AT VERIFICATION

[Sch 2 am LN 35 of 1993 reg 4, effective 24 May 1993]

SECTION A. MAXIMUM PERMISSIBLE ERRORS AT VERIFICATION

1. Measures of Length

The maximum permissible error from zero to any scale mark is—

(a) for lengths up to 500 mm ±0.5 mm

(b) for lengths over 500 mm but not over 2 m ±1 mm

(c) for lengths over 2 m but not over 100 m ± 0.5%

2. Masses

2.1 Metric masses

Maximum permissible error: (mg)
Denominationnon-ferrous masses marked “A”non-ferrous masses not marked “A”iron masses
1 mg+0.1
2 mg+0.2
5 mg+0.3
10 mg+0.4
20 mg+0.6
50 mg+0.9
100 mg+1.3
200 mg+2
500 mg+3
l g+4+60
2 g+5.5+60
5 g+9+60
10 g+12.5+120
20 g+18+120
50 g+28+120
100 g+40+120+240
200 g+60+170+340
500 g+90+270+540
1 kg+130+380+760
2 kg+220+650+1,300
5 kg+280+850+1,700
10 kg+400+1,200+2,400
20 kg+560+1,700+3,400

2.2 Metric carat masses

Denomination
(CM)
Maximum permissible error
(mg)
0.005+0.1
0.01+0.1
0.02+0.1
0.05+0.1
0.1+0.1
0.2+0.15
0.5+0.2
1+0.2
2+0.3
5+0.5
10+0.7
20+ 1
50+2
100+2
200+3
500+5

3. Measures of Volume

3.1 Comical Measures and Visible Bowl Liquid Measuring Instruments

Capacity
(L)
Maximum permissible error
(mL)
0.5+5
1+6
2+10
4+15
5+20
10+35
15+30
20+45
25+65

3.2 Cylindrical line — measures

Capacity
(L)
Maximum permissible error
(mL)
0.5±5
1±10
2±15
5±30
10±45
20±70

3.3 Pharmaceutical dispensing measures

3.3.1 Conical dispensing measures

Scale Mark (mL)Maximum permissible error at each scale mark (mL)
1±0.08
2±0.12
3±0.16
4±0.20
5±0.25
6,7,8±0.3
9±0.4
10±0.4
15±0.5
20±0.6
30±0.8
40,50± 1.0
60,70, 80, 90±1.5
100,120,140±2.0
160,180,200±3.0

3.3.2 Beaker dispensing measures

Capacity
(mL)
Maximum permissible error each scale mark on a particular measure
(mL)
500±5
1,000±7

3.4 Lubricating oil measures

Capacity
(L)
Maximum permissible error (mL)
0.5+20
1+30
2+50

3.5 Graduated measuring cylinders

Capacity
(mL)
Maximum permissible error
(mL)
5±0.1
10±0.2
25±0.5
50±1
100±1
250±2
500±5
1,000±10
2,000±20

4. Length — Measuring Instruments

Maximum permissible error for instruments with analogue indication: ±0.5%

Maximum permissible error for instruments with digital indication: ±0.5% +0.5

scale interval

5. Area — Measuring Instruments

Instruments shall be tested for single-measurement error and mean error

5.1 Single-measurement error:

5.1.1 Instruments with analogue indication:

Area of templet(s)
dm
Maximum permissible error (plus
and minus)dm
Not exceeding 25 dm
Exceeding 25 dm
0.5 dm
0.5 dm + ldm for each additional 50 dm part thereof

For instruments with digital indication add 0.5 scale interval to the maximum permissible error for an analogue instrument

5.2 Mean error:

On analogue and digital indicating instruments the mean of 20 measurements shall not differ from the denominated value of the templet by more than one, half the maximum permissible error specified in 5.1.1 above

Note: The test templets for measuring instruments with digital indication shall have values which are an integral number of square decimetres

6. Farm Milk Tanks The maximum permissible error for all scale marks on the dipstick is ±1 scale interval.

7. Vehicle Tanks

The maximum permissible error applicable to vehicle tanks provided with:

(a) a capacity mark, is ±0.2% of the indicated volume; and

(b) a dipstick, is ±0.5 scale interval for each scale mark on the dipstick, or sight tube scale marks.

8. Liquid measuring systems

8.1 Systems other than Volume Filling Instruments

8.1.1 The maximum permissible error applied during a verification test from normal flowrate to the minimum flowrate specified in the of pattern approval Certificate is ±0.3%

Note:The minimum flow rate for driveaway flowmeters is 15 L/min unless otherwise specified in the pattern approval certificate. Pattern approval tests will have established that, if calibrated in accordance with the above verification requirements at 20°C liquid temperature between 5°C and 40°C may increase by not more than 0.2% to allow for effect of viscosity charge.

8.2 Volumetric Drum Filling Instrument

The maximum permissible error for a volumetric drum filling instrument is + 0.15% of the volume delivered or filled.

8.3 Spirit-measuring instrument

Delivery (mL)Maximum Permissible error (mL)
15±0.6
30±1.0
60±1.5

8.3.1 Beer — Measuring Instruments

Delivery (mL)Maximum Permissible error
100 ml or over±1.5%

9. Weighing Instruments

9.1 Class 1, 2, 3 or 4 non-automatic instruments

9.1.1 The maximum permissible errors for increasing and decreasing loads, expressed in terms of verification scale intervale, with the instrument adjusted to zero within ± 0.25e at no load, are given in the Table:

Table

Maximum permissible error Load
Class 1Class 2Class 3Class 4
±0.5e0 to 50000e0 to 5000e0 to 500e0 to 50e
±leOver 50000eOver 5000eOver 500eOver 50e
up to 200000eup to 20000eup to 2000eup to 200e
±1.5eOver 2000000eOver 20000eOver 2000eOver 200

9.2 Unclassified non-automatic instruments

9.2.1 Unclassified even-arm scales

CapacityMaximum PermissibleError
BalancesBeam-ScalesCounter
Class AClass BClass CScales
5 g±4 mg±10 mg
25 g±6 mg±15 mg±60 mg
50 g±20 mg
100 g+30 mg
250 g±60 mg+240 mg
500 g±12 mg±100 mg±400 mg±1.5 g
1 kg+150 mg+600 mg±2.5 g
2 kg±250 mg±1 g±3.5 g
5 kg±70 mg±500 mg±2 g±6 g
10 kg±1 g±4 g±8 g
5 kg±1.5 g±6 g±10 g
25 kg±12 0 mg±2.5 g±10 g±15 g
50 kg±4.5 g±20 g±25 g

The maximum permissible error for even-arm scales shall be half the amount specified in the Table for loads up to half capacity and the whole amount specified for loads from half to maximum capacity.

9.2.2 Other unclassified instruments

The maximum permissible errors for self-indicating weighing instrument and graduated non-

self-indicating weighing instruments, with the instrument adjusted to zero within ± 0.25 scale

interval at no load shall be:

± half scale interval for the first 500 scale intervals

± one scale interval over 500 and up to 2000 scale intervals

± 1.5 scale intervals over 2000 scale intervals

9.3 Belt conveyor weighers

ClassMaximum permissible error
1± 0.5%
2± 1.0%

9.4 Weighing-in-motion Instruments

9.4.1 Maximum permissible static errors

Refer to 9.2.2.

9.4.2 Maximum permissible dynamic errors

After the instrument has been adjusted to zero at no load, the maximum permissible dynamic errors, at any speed with in the specified range, shall not be greater than the following—

(a) total train mass: ±5t or ±0.2% of the total train mass, whichever is the larger;

(b) wagon mass: 1t or ±1.0% of the wagon mass, whichever is the larger.

9.5 Weighing and Counting Scales

The limitations of error of the weighing and counting scale on inspection does not exceed plus or minus the mass of the smallest article the weighing and counting scale is designed and constructed to count.

9.6 Fabric Measuring Instrument

Length measuredError in Excess or Deficiency
1 metre5 mm
For each additional metre10 mm

9.7 Wheel Load Weighers

The limitation of error for the wheel load weighers at verification does not exceed plus or minus 3% of a load applied to the wheel load weigher.

9.8 Timing Devices

Nominal Time
Capacity
Maintenance and Acceptance
Tolerance
On over-registrationOn under-registration
30 minutes or lessNo Tolerance10 seconds per minute but not less than 2 minutes
Over 30 minutes up to and including one hourNo Tolerance10 seconds plus 4 seconds per minute over 30 minutes
Over one hourNo Tolerance2 minutes plus one minute per hour over one hour

Section B. Maximum Permissible errors at Reverification

Maximum Permissible Errors at Reverification

10. The following are the maximum permissible errors at reverification, where “v” is the absolute value of the maximum permissible error at verification.

Maximum permissible
error
DeficiencyExcess
Measures of lengthvv
Masses0.5vv
Measure of volume
(a)Glass measures:
— Line Measuresvv
— Brim measures0v
(b)Metal measures:
— Line measures2v2v
— Brim measuresvv
Length measuring instruments2v2v
Area measuring instruments2v2v
Fabric measuring instrumentsvv
Vehicle tanksvv
Liquid-measuring instrumentsv2v
Weighing instrumentsvv
Weighing and counting scalesvv
Wheel load weighers5%5%
Timing devicesvv