Transportation of goods by trucks plays an important role in the economy of a nation. The consignment of goods so transported is needed to be measured for its accuracy. This is important to maintain the trust level between the manufacturer and distributor on one hand, and the end customer on the other. The use of weighbridges and truck scales has increasingly become popular due to their ease of operation and accuracy in measurement. However, certain factors can impact the accuracy of a weighbridge and truck scale, the knowledge of which is important in order to reduce them. These factors can be categorized as related to human or system errors, environment, or mechanical.
Weighbridges or truck scales have become the popular weight measuring equipments in most parts of the world. Inspite of this, weighbridges often end up giving inaccurate measurements relating to the above mentioned factors. Interestingly, out of different types of weighbridges and truck scales, the platform based ones give the least errors.
Factors Impacting the Variation in Weight measurement
Environment: Factors such as temperature changes, wind, dirt, vibration, and moisture have an impact on accurate measurement. A poorly maintained weighbridge can have depositions of dirt and moisture in its electronic and mechanical components. Such depositions can prevent these components especially the load cells from working to their optimum level. And can even prevent a weighbridge from settling down to its desired level with the load thus leading to grossly inaccurate results. The best way to minimize variations due to such depositions is by washing the vehicle before it rolls on a weighbridge. Importantly, even a pronounced wind shear blowing by the truck can lead to deviation in measurement.
Moreover, there are systems present in weighbridges that can compensate for temperature variations. However, should these exceed the limit the measurement can turn out to be faulty. Another factor called vibration generated from nearby sources can impact the proper functioning of load cells. These can come from the nearby trucks, tool boxes, spare tyres or fuel present in the tank. This can be prevented or reduced by not allowing any vibrating source like trucks in the vicinity.
Human Error: During the weighing process no one should be present inside the truck. This is important from the point of view of reducing vibrations. Besides, if the truck is not fully rolled onto the weighbridge and a section of it remains outside, the result will be inaccurate.
Mechanical: Be it a China weighbridge and truck scale manufacturer or any other one from across the world, a leeway is generally given by the stamping authorities who approve these systems for quality. This leeway is due to the stated variations in the working of mechanical and electronic components that are present in a weighbridge. These variations often lead to deviations in measurements. Thus, a leeway of say +/- 20kg is generally allowed across countries on a 20-40 tonne load for a weighbridge of 60 ton capacity.
Also, there is an additional factor of poorly maintained weighbridges that lead to system errors in calibration.
The above mentioned errors can be minimized to the extent possible if proper procedures are followed during weighing. More importantly, weighbridges should be approved for quality only after following stringent checks.