GB/T 21296.2-2020 English PDF (GBT21296.2-2020)
GB/T 21296.2-2020 English PDF (GBT21296.2-2020)
GB/T 21296.2-2020: Automatic instruments for weighing road vehicles in motion -- Part 2: Weighing whole loads
NATIONAL STANDARD OF THE
PEOPLE REPUBLIC OF CHINA
Automatic instruments for weighing road vehicles in
motion - Part 2: Weighing whole loads
ISSUED ON: NOVEMBER 19, 2020
IMPLEMENTED ON: JUNE 01, 2021
Issued by: State Administration for Market Regulation;
Standardization Administration of the PRC.
Table of Contents
Foreword ... 4
1 Scope ... 5
2 Normative references ... 5
3 Terms and definitions ... 6
4 Type and specification... 8
4.1 Product type ... 8
4.2 Basic width ... 8
5 Metrological requirements ... 8
5.1 Accuracy level ... 8
5.2 Relationship between accuracy levels ... 9
5.3 Maximum permissible errors of in-motion test ... 9
5.4 Scale interval (d) ... 12
5.5 Maximum permissible errors of static test ... 12
5.6 Scale interval for stationary load ... 12
5.7 Minimum capacity (Min) ... 13
5.8 Influence quantity ... 13
6 Technical requirements ... 13
6.1 General ... 13
6.2 Suitability for use ... 13
6.3 Structural requirements ... 14
6.4 Control instrument ... 15
6.5 Anti-disturbance performance ... 16
7 Production and installation requirements ... 16
7.1 General ... 16
7.2 Load receptor ... 16
7.3 Installation ... 17
8 Installation conditions and maintenance requirements ... 18
8.1 General ... 18
8.2 Installation site conditions ... 18
8.3 Maintenance management ... 19
9 System function and data requirements ... 20
9.1 Basic functional requirements ... 20
9.2 Data storage, processing and transmission ... 21
10 Test methods ... 21
10.1 General ... 21
10.2 Preparation before testing ... 21
10.3 Static weighing test ... 22
10.4 In-motion weighing test ... 22
11 Inspection rules ... 22
11.1 Type test ... 22
11.2 Exit-factory inspection ... 24
11.3 Requirements for inspection items ... 24
12 Marking, packaging, transportation and storage ... 25
Bibliography ... 26
Automatic instruments for weighing road vehicles in
motion - Part 2: Weighing whole loads
This Part of GB/T 21296 specifies the terms and definitions, type and
specification, metrological requirements, technical requirements, production and installation requirements, installation conditions and maintenance
requirements, system function and data requirements, test methods, inspection rules, marking, packaging, transportation and storage of full-draught automatic instrument for weighing road vehicles in motion (hereinafter referred to as full- draught WIM).
This Part is applicable to the automatic instruments for weighing road vehicles in motion, which use the full-draught weighing method to determine the total weight of the driving vehicle (axle load or axle-group load, if applicable), when all the axles of the vehicle are driving on the load receptor of the weighing instrument, during the dynamic driving process of the road vehicle.
2 Normative references
The following documents are indispensable for the application of this document. For the dated references, only the editions with the dates indicated are applicable to this document. For the undated references, the latest edition (including all the amendments) are applicable to this document.
GB/T 7551 Load cells
GB/T 7723-2017 Fixed location electronic weighing instrument
GB/T 7724 Electronic weighing meter
GB/T 8923.1 Preparation of steel substrates before application of paints and related products - Visual assessment of surface cleanliness - Part 1: Rust grades and preparation grades of uncoated steel substrates and of steel substrates after overall removal of previous coatings
GB/T 14250 Terminology of weighing instruments
GB/T 15395 General technical specification for cabinet of electronic
The sum of all axle loads in the defined axle-group.
[GB/T 21296.1-2020, definition 3.3.16]
Wheel and axle recognizer
A device used to identify the wheel and axle of a vehicle.
Note: The method installed in the weighing platform is called the embedded wheel and axle recognizer. It can also be installed on both ends of the load receptor. 3.6
Scale interval; d
The difference, expressed in mass units, between two adjacent indicating values or printed values of weighing-in-motion.
[GB/T 21296.1-2020, definition 3.3.23]
Controlled weighing area
The specific location where the WIM performs the weighing operation; the location meets the installation requirements of this Part.
[GB/T 21296.1-2020, definition 3.2.1]
The road surface area consisting of the load receptor and its aprons forward and backward in the direction of travel.
Note 1: The length from the starting point to the end point of the weigh zone along the driving direction is called the length of the weigh zone.
Note 2: The end of the incoming vehicle is the starting point of weigh zone. The end of the vehicle driving away is the end point of weigh zone.
[GB/T 21296.1-2020, definition 3.2.2]
The rigid foundation with the physical properties of load receptor, which is located at the two ends of the load receptor along the driving direction. Note: The main function is to, during weighing, provide a relatively straight, relatively horizontal and smooth travel route for the vehicle under test when it enters the load receptor.
Operating speed; v
The average speed, the vehicle under test passing through the load receptor, at which normal weighing-in-motion can be carried out.
[GB/T 21296.1-2020, definition 3.3.25]
Maximum operating speed; vmax
The maximum vehicle speed at which normal weighing-in-motion can be carried out as stipulated by the design of the weighing instrument. If this speed is exceeded, the weighing result may cause excessive relative error.
[GB/T 21296.1-2020, definition 3.3.26]
4 Type and specification
4.1 Product type
The product type shall comply with the provisions of GB/T 26389 and 4.6 of GB/T 21296.1-2020.
4.2 Basic width
The width of the load receptor shall meet the economical width required by the weighed vehicle. Its typical values are 3 m and 3.4 m. The length of single section structure is generally less than 7 m.
5 Metrological requirements
5.1 Accuracy level
5.1.1 Principles for determining accuracy level
If the WIM is not suitable for liquid-loaded vehicles, it shall be clearly indicated in the manual and nameplate.
6.2.2 The welding parts shall be welded firmly and reliably. The welds shall be uniform, flat, free of cracks, have no welding slag. There shall be no defects such as undercut or solder skipping. It shall meet the requirements of QB/T 1588.1.
6.2.3 The surface of the casting shall be smooth and clean. There shall be no defects such as shrinkage porosity, cold separation, cracks, pores and slag inclusion.
6.2.4 Forgings shall be free of defects such as cracks, interlayers, and slag inclusions. Machinery cutting parts shall meet the requirements of QB/T 1588.2. 6.2.5 The surface of the electroplated parts shall be uniform in color. There shall be no defects such as spots and rust.
6.2.6 Before the load receptor is painted, the surface shall be de-rusted. It shall meet the requirements of GB/T 8923.1.
6.2.7 The paint layer on the surface shall be smooth, consistent in color, bright and firm. The paint layer shall not have defects such as brushing, sagging, wrinkling, air bubbles, peeling, shedding. After painting, the surface shall be intact without exposed undercoat. It shall meet the requirements of QB/T 1588.4. 6.3 Structural requirements
6.3.1 Load receptor
The load receptor of the full-draught WIM shall be able to ensure that, all the tyres of the tested vehicle are located on the load receptor. The load receptor can be a single-section structure, or a multi-section structure connected (combined) together. For the needs of axle weighing, a combination of
embedded weighing platform or multi-section load receptor can be used. There shall be anti-skid measures on the surface of the load receptor. When the full- draught WIM bears the load of 125% the maximum capacity, the components of the weighing instrument shall not be permanently deformed or damaged. 6.3.2 Wheel and axle recognizer
The wheel and axle recognizer can be installed on the load receptor, as an integrated structure. It can also be installed on both ends of the load receptor, as a separate structure.
6.3.3 Vehicle identification device
greater than ??0.25d of the scale interval for static verification.
6.4.3 Partial load
The error of the indicating values of the same load at different positions of the load receptor shall not be greater than the maximum permissible errors of the verification in 5.5.
When the weighing instrument is in a balanced state, gently put on or take off the weight, which is equivalent to 1.4 times the scale interval for static verification. At this time, the original indicating value of the weighing instrument shall be changed.
6.4.5 Repeatability error
The difference between the results of multiple weighings of the same load shall not be greater than the absolute value of the maximum permissible errors under the load.
6.5 Anti-disturbance performance
The full-draught WIM, as an electronic vehicle weighing instrument, shall meet the requirements of electronic instrument. It shall meet the requirements of 6.4 in GB/T 21296.1-2020.
7 Production and installation requirements
The realization of the accuracy level of the full-draught WIM is not only related to the design, production, and installation of the weighing instrument itself; but also related to the conditions such as levelness, slope, curvature, and road strength of the weigh zone. In addition, it is related to the daily maintenance of the weighing instrument. Users shall have a correct understanding of this. In addition to meeting the requirements of Clause 7 in GB/T 21296.1-2020, it shall also meet the requirements of 7.2~7.3.
7.2 Load receptor
The height of the installation fixing point of each load cell of the load receptor shall be consistent; meet the requirements of the drawing.
8 Installation conditions and maintenance
Users shall realize that, the realization of the performance of the full-draught WIM not only depends on the weighing instrument itself; but also includes the environmental conditions of the site, where the weighing instrument is installed, and the use and maintenance level of the WIM. The performance required by the user shall match the environmental conditions of the site installation. If restricted by objective conditions, the installation environmental conditions cannot meet the requirements, then the WIM shall be degraded and used.
8.2 Installation site conditions
8.2.1 Principles for selection of installation site
The selection of the installation area of the full-draught WIM follows the following principles:
a) The road conditions before and after the installation area shall be
b) It shall not be installed under high-voltage power lines or near radio transmission stations and railway tracks;
c) The concrete pavement construction in the installation area shall be implemented in accordance with the relevant requirements of the
d) The asphalt pavement construction in the installation area shall be
implemented in accordance with the relevant requirements of the
e) The distance between the installation location of the weighing instrument and the entrance and exit of the highway tunnel on the same road section shall be no less than 2 km and no less than 1 km, respectively.
8.2.2 Installation road surface conditions
The installation position of the load receptor of the full-draught WIM shall ensure that, the center line of the load receptor is located near the center of the weigh zone in the driving direction. The installation road surface conditions are as specified in Table 8.
If problems are found, correct them in time.
8.3.4 Equipment lubrication and maintenance
Regularly check whether the parts of the full-draught WIM that need to be lubricated meet the manufacturer's requirements. If not, perform lubrication according to the requirements. Check whether the welding part of the load receptor is un-welded. If yes, perform repair-welding in time. Check whether the paint of the load receptor is peeling off or aging; whether the road traffic sign lines are clear. When peeling off or aging, touch up the paint in time. 8.3.5 Pavement inspection and maintenance
Regularly check the condition of the road surface in the controlled weighing area; to see if there are loose roads, pits, subsidence, bulges, cracks, and chaps that affect the weighing. When it appears, fix it in time.
8.3.6 Power supply and grounding inspection
Regularly check whether the power supply of the equipment is stable and appropriate; whether the ground wire is firmly connected; whether there is rust. If necessary, it shall test the grounding resistance. If it does not meet the manufacturer's requirements, take corrective measures in time.
8.3.7 Weighing accuracy check
Regularly (according to the frequency of use, laws and regulations, user or manufacturer designation, etc.) check the weighing accuracy. When inaccuracy is found, repair or re-adjust in time. When necessary, the control instrument can be used for inspection.
8.3.8 Full-time equipment maintenance and management
Users shall set up full-time maintenance and management personal positions for weighing equipment; receive corresponding professional training; formulate care and regular inspection and maintenance systems; to ensure that the weighing equipment is not accidentally adjusted.
9 System function and data requirements
9.1 Basic functional requirements
The weighing accuracy of the full-draught WIM shall be consistent with the accuracy level of the full-draught weight, axle load, and axle-group load (if 10.2.2 Adjustment
All adjustments are carried out at the actual installation location of the full- draught WIM; including static adjustment, in-motion adjustment and speed adjustment. The in-motion adjustment shall use the vehicle expected to be used by the full-draught WIM; shall be carried out in accordance with the adjustment method provided by the manufacturer. When the adjustment is over, the
corresponding records shall be kept.
All adjustments shall be carried out before delivery or submission to the metrological department for verification.
10.2.3 Installation and visual inspection
Check whether the combination between the full-draught WIM and the road surface is smooth after installation. Check whether the flatness and slope of the apron at both ends meet the requirements. Check whether there is debris at the joint between the full-draught WIM and the road surface. Visually inspect whether the appearance (paint quality, welding quality, etc.) meets the requirements.
10.3 Static weighing test
For the full-draught WIM with a static working mode used as a control
instrument, all static tests are performed in accordance with Appendix D of GB/T 21296.1-2020. The relevant module test requirements shall be implemented in accordance with Appendix E of GB/T 21296.1-2020.
10.4 In-motion weighing test
It shall be carried out in accordance with 10.4 of GB/T 21296.1-2020.
11 Inspection rules
11.1 Type test
The full-draught WIM designed and manufactured by the manufacturer shall undergo a type test.
Under the following conditions, the full-draught WIM shall be type tested: a) Before the new product is put into production for the first time;
b) The first lot of products after major changes in design, technology, and key