GB/T 21296.2-2020 PDF English

GB/T21296.2-2020 (GBT21296.2-2020): PDF in English

GB/T 21296.2-2020 GB NATIONAL STANDARD OF THE PEOPLE’S REPUBLIC OF CHINA ICS 17.100 N 13 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 1 Scope 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 equipment Axle-group load The sum of all axle loads in the defined axle-group. [GB/T 21296.1-2020, definition 3.3.16] 3.5 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] 3.7 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] 3.7.1 Weigh zone 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] 3.7.2 Apron 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. 3.8 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] 3.9 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. 6.4.4 Discrimination 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 7.1 General 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 al.......
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