Weigh-In-Motion Standards Comparison between China GBT 21296 and OIML R134

 

Weigh-In-Motion Standards Comparison

between China GBT 21296 and OIML R134

WIM Comparison between China GB/T 21296 and OIML R134
Comparison Item	OIML R 134-1	China GB/T 21296	Remarks
Weighing Classification	No explicit classification based on speed.	Classified by speed: Low-speed (≤10 km/h), Medium-speed (10–40 km/h), High-speed (40–100 km/h)	GB/T 21296 defines three categories based on speed, adapting to different traffic and operational conditions. OIML R 134-1 focuses on dynamic weighing but does not specify speed ranges
Vehicle Mass Accuracy Classes	6 accuracy classes: 0.2, 0.5, 1, 2, 5, 10	6 basic accuracy classes: 0.2, 0.5, 1, 2, 5, 10; Two additional classes: 7, 15	China’s standard adopts the 6 classes from OIML R 134-1 and introduces 2 additional classes for lower-precision applications
Axle Load Accuracy Classes	6 classes: A, B, C, D, E, F	6 basic classes: A, B, C, D, E, F; 2 additional classes: G, H	GB/T 21296 adopts the axle load classification from OIML R 134-1 and adds G and H for applications requiring higher tolerance
Maximum Permissible Error (MPE)	Vehicle mass: 0.2%-10%; Axle load: 0.5%-8%	Vehicle mass: 0.2%-15%; Axle load: 0.5%-30%	China’s standard extends the permissible error to suit broader WIM applications.
Testing Methods	Dynamic and static testing using control instruments	Dynamic and static testing; details specific error calculation methods	Both standards require dynamic and static testing. GB/T 21296 expands the methods, specifying tests for different speed ranges and system types​
Environmental Conditions	General environmental conditions (temperature, humidity)	Temperature (-10°C to 40°C), humidity (≤85%)	China’s standard provides more stringent environmental requirements, ensuring systems perform in varied climates and installation conditions​
Installation Guidelines	Focus on system suitability for intended use	Specifies detailed installation guidelines, including road surface and slope requirements	GB/T 21296 adds more specific requirements for the installation of WIM systems, ensuring accurate performance based on road conditions​

 

OIML R 134-1

OIML R 134-1 is an international recommendation document issued by the International Organization of Legal Metrology (OIML), with the full title "Automatic instruments for weighing road vehicles in motion."

OIML R 134-1 is primarily applied to vehicle weighing systems in highway toll stations, freight management, traffic law enforcement, and similar applications.

1.      Vehicle mass

For determining the vehicle mass, WIM instruments are divided into six accuracy classes as shown below:

0.2       0.5       1          2          5          10

2.      Single-axle load and axle-group load

For determining single-axle load and, if required axle-group load, WIM instruments are divided into six accuracy classes as shown below:

A          B          C         D         E          F

Relationship between accuracy classes

The relationship between the accuracy classes for single-axle load and, if required, axle-group load and the accuracy classes for vehicle mass are as specified in Table 1 below.

 

Accuracy class single-axle load and axle-group load	Accuracy class for vehicle mass
	0.2	0.5	1	2	5	10
A	✓	✓
B	✓	✓	✓
C		✓	✓	✓
D			✓	✓	✓
E				✓	✓	✓
F						✓

 

3.      Vehicle mass

The maximum permissible error for the vehicle mass determined by in-motion weighing, shall be one of the following values:

 

Accuracy class for vehicle mass	Percentage of conventional value of the vehicle mass
	Initial verification	In-service inspection
0.2	±0.10 %	±0.20 %
0.5	±0.25 %	±0.50 %
1	±0.50 %	±1.00 %
2	±1.00 %	±2.00 %
5	±2.50 %	±5.00 %
10	±5.00 %	±10.00 %

 

4.      Maximum permissible error for two-axle rigid reference vehicle

Accuracy class for single-axle load	Percentage of conventional true value of the static reference single-axle load
	Initial verification	In-service inspection
A	±0.25 %	±0.50 %
B	±0.50 %	±1.00 %
C	±0.75 %	±1.50 %
D	±1.00 %	±2.00 %
E	±2.00 %	±4.00 %
F	±4.00 %	±8.00 %

 

 

GB/T 21296

GB/T 21296 is a Chinese national standard.

This standard specifies the metrological and technical requirements for automatic weighing instruments used to determine the total vehicle mass, axle loads, and axle-group loads of road vehicles when the vehicles are weighed in motion.

GB/T 21296 is widely used in China for applications such as highway weight enforcement, toll collection systems, freight management, and port logistics where accurate vehicle weight measurement is required.

 

1.      The basic accuracy grades for vehicle gross weight of WIM instruments are divided into 6 levels, represented by the symbols: 0.2, 0.5, 1, 2, 5, 10.

2.      The basic accuracy grades for single axle loads and axle group loads (if required) of WIM instruments are divided into 6 levels, represented by the symbols: A, B, C, D, E, F.

3.      The additional accuracy grades for vehicle gross weight of WIM instruments are divided into 2 levels, represented by the symbols: 7, 15.

4.      The additional accuracy grades for single axle loads and axle group loads (if required) of WIM instruments are divided into 2 levels, represented by the symbols: G, H.

 

5.      Relationship between accuracy classes

The relationship between the accuracy classes for single-axle load and, if required, axle-group load and the accuracy classes for vehicle mass are as specified in Table below.

 

Accuracy class single-axle load and axle-group load	Accuracy class for vehicle mass
	0.2	0.5	1	2	5	7	10	15
A	✓	✓	—	—	—	—	—	—
B	✓	✓	✓	—	—	—	—	—
C	—	✓	✓	✓	—	—	—	—
D	—	—	✓	✓	✓	✓	—	—
E	—	—	—	✓	✓	✓	✓	—
F	—	—	—	—	—	✓	✓	—
G	—	—	—	—	—	—	—	✓
H	—	—	—	—	—	—	—	✓

 

6.      Maximum Permissible Error (MPE) for vehicle gross weight

 

Accuracy class for vehicle mass	The percentage of the total vehicle weight agreed true value
	Initial verification	Calibration	In-service inspection
0.2	±0.10%	±0.16%	±0.2%
0.5	±0.25%	±0.40%	±0.5%
1	±0.50%	±0.80%	±1.0%
2	±1.00%	±1.60%	±2.0%
5	±2.50%	±4.00%	±5.0%
7	±3.50%	±5.60%	±7.0%
10	±5.00%	±8.00%	±10.0%
15	±7.50%	±12.00%	±15.0%

 

7.      Maximum permissible error for two-axle rigid reference vehicle

 

Accuracy class for single-axle load	Percentage of conventional true value of the static reference single-axle load
A	±0.50%
B	±1.00%
C	±1.50%
D	±2.00%
E	±4.00%
F	±8.00%
G	±10.00%
H	±15.00%