​Non-Automatic Weighing Instruments​

​In 2015 APLMF agreed to summarise the test procedures used in each APLMF training course and then to survey its members to validate the test procedures and to provide some quality control. The validated test procedures will be later used to develop eLearning modules. 

The summary test procedures are provided to guide economies wishing to follow OIML recommendations. They contain abbreviated terms and formulae which are defined in the relevant OIML recommendation.

Information relating to​ Non-Automatic Weighing Instruments​:
​​SUMMARY OF TEST PROCEDURES USED TO VERIFY ​NON-AUTOMATIC WEIGHING INSTRUMENTS​
​Test Name
​Procedures Description
VISUAL INSPECTION
  • Visually inspect the instrument for compliance with the certificate of approval 
  • Where applicable, check that the instrument is level
  • Check for compliance with any relevant regulations/environmental factors/mode of use
REPEATABILITY​
  • Determine the applied load (Approx. 2/3 capacity or just below 2nd MPE change point for instruments with only 2 MPE change points)
  • Zero the instrument 
  • Apply load and set the indication to centre ‘e’ (Add 0.5e, bring indication to just above next changeover point using change point masses of 0.1e, remove 0.5e)
  • Remove all load, reset zero, then re-apply load (including change point masses, twice more ensuring instrument returns to zero between each weighing
  • Where all indications are the same instrument passes
  • Where any indications differ check to see if the instrument is within the MPE
ECCENTRICITY
  • Determine the applied load (1/3 capacity except for instruments with more than 4 points of support, hopper weighers, instruments with minimal off-centre loading, and instruments used for rolling loads) 
  • Determine the individual surface areas of the load receptor where the loads are to be applied
  • For each surface area, zero instrument, apply the load and determine if the indication is within the MPE
ZERO SETTING
Only performed at initial verification, when system changes affect these functions (Non-automatic and semi-automatic only)
  • ​Apply a load within the zero-setting range and bring the indication to just below the next changeover point using change point masses of 0.1e
  • Re-set the indication to zero using the zero-setting device
  • Apply 10e to the load receptor
  • Apply 0.25e and the indication shall remain the same 
  • Apply an additional 0.5e and the indication shall change up 1e
​ZERO TRACKING
Only performed at initial verification, when system changes affect these functions (Non-automatic and semi-automatic only)
  •  Re-set the indication to zero using the zero-setting device
  • Apply 1e to the load receptor
  • After 5 seconds the indication shall change up 1e
WEIGHING PERFORMANCE
  • ​Zero the instrument 
  • Apply at least 5 increasing loads at approximately equal steps, including minimum capacity, all MPE change points, any scale interval change points (minus 5e if weighing instrument has + error) and maximum capacity (minus 5e if over-range blanking occurs)
  • Check over-range blanking
  • Remove load in a minimum of 3 steps from maximum to minimum capacity, in approximately equal steps
  • Check instrument has returned to zero
DISCRIMINATION
  • ​At any load (usually the same load as repeatability) bring the indication to just over the change point. The addition of a further 1.4e shall cause an increase in the indication by 1 verification scale interval
  • A supplementary test is required if the instrument has an initial zero-setting range greater than 20%
ACCURACY OF TARE SETTING
Only performed at initial verification, when system changes affect these functions (Non-automatic and semi-automatic only)
  • Load the instrument using a weight that exceeds the marked tare capacity to ensure the tare facility is not functional at this load
  • Apply a load within the tare setting range and bring the indication to just below the next changeover point using change point masses of 0.1e
  • Re-set the indication to zero using the tare-setting device
  • Apply 10e to the load receptor
  • Apply 0.25e and the indication shall remain the same 
  • Apply an additional 0.5e and the indication shall change up 1e
  • Remove the additional 0.25e, 0.5e and 10e leaving the change point masses with the load 
  • Add a load equal to full remaining capacity and determine if the indication is within MPE for remaining applied load
​PRICE-COMPUTATION
Only performed at initial verification, when system changes affect these functions (Non-automatic and semi-automatic only)
  • ​Check at least 5 price computations over a range of different loads
​​Summary of Economy Reports
Verification of NAWI training 28 November to 1 December 2016.
Economy
Legislation
SI
MPE used
Inspector or 3rd party
Verification periods
Bangladesh 
Yes
Yes
Not set yet
Inspectors
Yes in legislation
Bhutan
Yes
Yes
As per R76
Inspectors
Yes, 6 months
​or 1 year
Cambodia
Yes
Yes
As per R76
Inspectors
1year
Fiji
Yes
 Yes
As per R76
Inspectors
-
Malaysia
Yes
Yes
As per R76
3rd Party
(Metrology Corporation)
1 Year
Mongolia
Yes
Yes
As per R76
Inspectors
-
Nepal
Yes
Yes
As per R76
Inspectors
-
Papua New Guinea
Yes
Yes
As per R76
Inspectors
-
Philippines
Yes
Yes
As per R76
Inspectors
-
Sri Lanka
Yes
Yes
As per R76
Inspectors
1 Year
Thailand
Yes
Yes
​As per R76
Inspectors
-
Uzbekistan
​Yes
​Yes
​As per R76
Inspectors
1 Year
Vietnam
​Yes
​Yes
As per R76
​Inspectors
-
Economy
OIML compliant
Type approval
Issues
Other
Bangladesh
​Some what
No
​More equipment and knowledge
 - 
Bhutan
Yes
No
-
-
Cambodia
Yes
No
No facilities for PA
Lack of experts
Limited budget
Limited standards
-
Fiji
Yes
Yes
Budget – standards
Lack of investment
Need technical assistance
-
Malaysia
Yes
Yes
​Software verification
-
Mongolia
-
Yes
-
-
Nepal
-
Yes
Lack of trained manpower
Act 40 y old
Low penalty for fraud
-
Papua New Guinea
-
No
-
-
Philippines
Yes
No
​National Metrology Board not convened
Lack of technical guidelines
No digital verification
Lots of work 
Sri Lanka
Yes
Yes
​District but no divisional inspectors
Need more staff
Consumer education​
-
Thailand
Yes
No
-
-
Uzbekistan
Yes
Yes
-
-
Vietnam
Yes
No
-
-
SURVEY RESULTS ON ADOPTING THE ​​​NON-AUTOMATIC WEIGHING INSTRUMENTS​ TEST PROCEDURES
The following results are from a survey completed in 2016. 
Test name
Total economies surveyed
Agree
Disagree
Economies not responded
1. Visual Inspection
19
10
1
9
2. Repeatability
19
9
1
9
3. Eccentricity
19
9
1
9
4. Zero Setting
19
9
1
9
5. Zero Tracking
19
9
1
9
6. Weighing Performance
19
10
Value
9
7. Discrimination
19
9
1
9
8. Accuarcy of Tare Setting
19
9
1
9
9. Price Computation
19
9
1
9
Does your economy's test procedures generally align with the test procedures described above
19
8
1
10
​Economies who responded:
Australia, Cambodia, Canada, Japan, New Zealand, Papua New Guinea, Philippines, Singapore, Chinese Taipei, Vietnam