The fixed dynamic axle weighing truck scale is the most widely used device in my country for measuring vehicle weight and monitoring vehicle overload at toll stations. It has long become a familiar measuring device and a standardized product of scale manufacturers. However, there are still some issues worth discussing about its calibration.
1. Static calibration of axle weighing truck scale
According to the calibration regulations, the axle weighing truck scale must first be calibrated by static weighing. The maximum weighing capacity of the axle weighing truck scale can reach 20t. Even when certifying the product, it is not easy and has certain dangers to place a 20t weight on a carrier of more than 3 square meters to calibrate the axle truck scale. As for the site of the highway toll gate, it is extremely difficult to use weights for maximum weighing calibration. Especially in the absence of a special hoisting weight device, it is almost impossible to complete. Usually, we mostly use a small amount of weights for calibration, and the error caused by the calibration result is often very different from the requirements of the calibration regulations.
I think the most reasonable method is to use digital or non-code calibration technology. In fact, this technology has been widely used and recognized by legal departments abroad in the past 20 years.
2. Dynamic calibration of axle weighing truck scales
1. The standard instrument for dynamic calibration of axle weighing truck scales is a "dual-axle rigid vehicle" according to international recommendations. Compared with the standard instrument used for static scale verification, the weight, its strictness is quite different. As a standard instrument, the nominal mass and uncertainty value of the weight are unique. No matter when and where it is used to calibrate the static scale, its uncertainty value or error is consistent and repeatable. However, as a "dual-axle rigid vehicle" is used as a "static reference axle load value", it is difficult to ensure the consistency of the measured axle load as a "conventional true value" in this case. Since the vehicle cannot be ideally "rigid", the "center of gravity movement" of the vehicle makes the "total load value" obtained by adding the load values weighed on the two axles separately, the uniqueness of the result obtained for the same vehicle using different calibration scales at different locations is more arbitrary than that of weights. Its error is not at the same level as the repeatability of the weight error value, and it is difficult to reach the level of the track scale
standard bridge scale vehicle.
The following is an analysis and discussion based on the data of the "reference vehicle" used for calibration.