1. NMi WIM standard Cock Oosterman NMi Certin
Hans van Loo Corner Stone Int.

2. Topics Development Implementation Background Content Test Procedures
Weigh-In-Motion Standard
Topics
Development
Background
Content
Test Procedures
Implementation
3 Elements
Data Quality Management
Type Approval Procedure

3. Development of Standard
Weigh-In-Motion Standard
Development of Standard
Dutch, Independent, Test, Inspection, Calibration and Certification Institute
1000 years of experience in Global Legal Metrology
Certification & Acceptance
World wide Certification (OIML)
European Approvals (CE)
National Approvals (Enforcement)

4. Development of Standard
Weigh-In-Motion Standard
Development of Standard
Legal Applications: Direct Weight Enforcement and Tolling by Weight
Metrology: The measurements of the Weigh-In-Motion systems are used directly as basis for fine/fee.
Benefits: Most efficient way of weight enforcement and tolling by weight without any impact on the traffic flow
Guarantee: All issued fines/fees must be justified, hence all measurements should always be within specification.

5. Development of Standard
Weigh-In-Motion Standard
Development of Standard
3 International Standards
COST-323, ASTM-E1318, OIML-R134
Each with own purpose and (dis-)advantages
Parts used in tenders
None for legal applications at high speeds
Many National Standards
All different
Often not practical
Limitation for new applications
Barrier for market access

6. Development of Standard
Weigh-In-Motion Standard
Development of Standard
HIGH SPEED
Free Flow Conditions
With Vehicle Dynamics
LOW SPEED
Controlled Conditions
No Vehicle Dynamics
4 Areas of WIM
LEGAL APPLICATIONS
Accuracy of each measurement
Specified in MPE (100%) HS
Legal LS
Legal
Direct Weight Enforcement
Tolling by Weight
STATISTICAL APPLICATIONS
Accuracy of average measurement
Specified in 2σ (95%) HS
Stat. LS
Stat.
Statistics on Traffic Loading
Pre-Selection Enforcement
???

7. Development of Standard
Weigh-In-Motion Standard
Development of Standard
NMi WIM Initiative (2016)
Scope:
Automatic WIM-systems.
High Speed and Low Speed
Performance Requirements
Minimum Testing Procedures
Application:
Technology Independent
Legal and Statistic Applications
International use, free of charge
NMi
WIM
STANDARD

8. Development of Standard
Weigh-In-Motion Standard
Development of Standard
NMi WIM Initiative
International Expert Group:
Different Manufactures
Different Technologies
Legal Metrology
> 100 year experience
Balance between:
Theoretical requirements
Practical conditions
NMi
WIM
STANDARD

9. Development of WIM Standard
Weigh-In-Motion Standard
Development of WIM Standard
Guide to Standard with:
Reasons and motivation to develop a new standard and the approach
Explanation of the scope, application and structure
Explanation of the different level of performance tests
The procedures for acceptance
Explanations for choices made in the development of the standard itself.

10. Development of Standard
Weigh-In-Motion Standard
Development of Standard
Operating Conditions:
Ranges for: Speed, Temperature Humidity, EMC, Mains Variation
Technical Requirements:
Vehicle Record, Completion Rate
Time + Speed Recording
Length Measurement
Vehicle Classification
Weighing Requirements:
Accuracy Classes, eg. L(5) S(10)

11. Development of Standard
Weigh-In-Motion Standard
Development of Standard
Specification of Accuracy classes:
Legal applications; L(x)
[-MPE, +MPE] interval
Includes 100% of measurements
Class
L(3)
L(5)
L(7)
L(10)
GVW 3 5 7 10
Axle Group 8 11 15
Axle Load 20

12. Development of Standard
Weigh-In-Motion Standard
Development of Standard
Test Procedures
Legal Applications
3 test levels
Independent Metrological Approval
Testing and Certification by NMi
or approved National Authority
Statistical Applications
2 Test levels
Relation between Buyer and Vendor

13. Development of Standard
Weigh-In-Motion Standard
Development of Standard
Type Approval:
New Type of System
Pre-approval
Laboratory Tests
Large Field Test (90 runs)
Initial Verification:
After Installation
Medium Field Test (60 runs)
In-service Verification:
After certain period (1 year)
Small Field Test (30 runs)

14. Topics Development Implementation Background Content Test Procedures
Weigh-In-Motion Standard
Topics
Development
Background
Content
Test Procedures
Implementation
3 Elements
Data Quality Management
Type Approval Procedure

15. Implementation of Standard
Weigh-In-Motion Standard
Implementation of Standard
Legal Acceptance
Legal Acceptance
Provides legal basis for use of WIM
Requirements for:
System Accuracy & Reliability
System Operation & Maintenance (Data Quality Management)
Included in National Legislation
Based on International/NMi Standard
System Approval
Data Quality Management

16. Implementation of Standard
Weigh-In-Motion Standard
Implementation of Standard
Preparations for Legal Acceptance in:
Czech Republic;
Netherlands;
Ireland;
Estonia:
Austria;
Poland;
Brazil;
Argentina;
? ? ?

17. Implementation of Standard
Weigh-In-Motion Standard
Implementation of Standard
Legal Acceptance
System Approval
Provides metrological reference
Formal system testing & certification
Type Approval,
Initial Verification
In-Service Verification
Based on international/NMi standard
System Approval
Data Quality Management

18. Implementation of Standard
Weigh-In-Motion Standard
Implementation of Standard
Type Approval:
Pre-approval Fase
Assessment of:
All existing documentation
Previous test results
Determination of
Possible missing documentation
Acceptance of previous test results
Description of required Tests procedures
Planning of next Fases
Overview of Costs

19. Implementation of Standard
Weigh-In-Motion Standard
Implementation of Standard
Pre-approval Fase
Laboratory Tests
At NMi Lab in Dordrecht or
Approved National Lab
Testing of:
Temperature + Humidity
Immunity to EMC, Mains variations
Hard- and Software Security

20. Implementation of Standard
Weigh-In-Motion Standard
Implementation of Standard
Pre-approval Assessment
Laboratory Tests
Field Tests
At customer location
Organization by Customer
Supervision by NMi (or CSI)
Testing :
3 different test-trucks, fully loaded*
30 runs each spread over speed range
Accepted if: No error > 0.5 * MPE
* For Weight Enforcement

21. Implementation of Standard
Weigh-In-Motion Standard
Implementation of Standard
Legal Acceptance
Data Quality Management
Proof of operational stability
Through combination of:
Continuous Checks
Maintenance
Calibration
Included in the Quality System for the operation of the WIM system
System Approval
Data Quality Management

22. Implementation of Standard
Weigh-In-Motion Standard
Implementation of Standard
Legal Acceptance and System Approval
Initial Verification
In-Service Verification
In-Service Verification
Legally Specified Max. Error √ √ √
Unknown Real Error
6 months
12 months

23. Implementation of Standard
Weigh-In-Motion Standard
Implementation of Standard
Not always enough!
Initial Verification
In-Service Verification
In-Service Verification
Specified Max. Error √ √ √
Unknown Real Error
6 months
12 months

24. Implementation of Standard
Weigh-In-Motion Standard
Implementation of Standard
What happens in between?
Initial Verification
In-Service Verification
In-Service Verification
Specified Max. Error √ √ √ ? ?
Unknown Real Error
6 months
12 months

25. Implementation of Standard
Weigh-In-Motion Standard
Implementation of Standard
Purposes of Data Quality Management (DQM):
to make sure the WIM systems continue to operate within specifications in between ’hard’ system verifications.
to provide input for maintenance, trouble shooting and calibration of the WIM systems
Data Base
Good
Data
Bad
WIM systems
Users
Data Quality Checks
Problem
Assessment
Calibration
Maintenance

26. Conclusions New NMi WIM Standard: Implementation requires 3 Elements:
Weigh-In-Motion Standard
Conclusions
New NMi WIM Standard:
High Speed and Low Speed WIM
Legal and Statistic Applications
Performance Requirements
Minimum Testing Procedures
Technology Independent
International use;
Free of charge
Implementation requires 3 Elements:
Legal Acceptance
System Approval
Data Quality Management

27. Download at NMi website: http://www.nmi.nl/nmi-wim-standard/
Weigh-In-Motion Standard
More Information
Download at NMi website:
Or contact:
Cock Oosterman:
Hans van Loo:
Free to use!