How Truck Scale Weighing Systems Work

Why Truck Scale Weighing Stations Exist

Hundreds of thousands of people pass truck weighing stations throughout the country every day, completely unaware of their significance and the intricate moving parts that comprise these systems. Before we address how these scale systems work, it’s important to know why they exist in the first place! Most states require that trucks used for the transport of materials be routinely weighed for two reasons— firstly, states can collect taxes based on the weight of the load that trucks are carrying. Secondly, trucks need to be regularly and accurately weighed to make sure that they fall within the safety restrictions put in place in regards to what the road is designed to handle. In general, the safe weight limit for commercial trucks is around 17 tons or 34,000 pounds. This weight is calculated by determining the axle weight, or how much each axle is supporting, and the total gross weight of the truck.

Different Types of Truck Scale Systems

When trucks are throwing around serious weight, like 17 tons, then the scales used to accurately measure the weight of these trucks need to be able to stand up to incredible abuse. To accommodate these needs, there are a few different scale systems that are used throughout the country.

Load-Cell Truck Scales

Most of the time, this is the variety of scale systems that you see along America’s highways. This scale system is made up of cells made from steel, which has a device called a strain gauge embedded inside of it. This gauge is specially designed to register changes in its electrical current when weight is applied to the cell. These electrical variations are recorded and used to calculate the mass of the object that caused the variations. 

These gauges come in two varieties— compression strain gauge and tension strain gauge. The difference between the two is that the compression gauge’s electrical signature is altered by how much the cell compresses by the weight applied to it, and tension gauges are affected by the change in shape to the cell when weight is applied. 

Bending Plate Truck Scale

This truck scale system is quite similar to the load cell system, with one major difference— the bending plate system uses metal plates with strain gauges rather than steel cells. These steel plates bend under the pressure applied by the truck’s weight, as the name implies, and that pressure is recorded by the strain gauges. The strain gauges record the pressure data and translate it into a mass required to produce that amount of pressure. On paper, it sounds quite simple! There are a lot of components to these scales, however, that may require attention from an expert team like the technicians at Walz Scales.

Piezoelectric Truck Scale

Piezoelectricity is the word used to describe the process by which certain minerals can generate an electrical charge when they are subjected to mechanical stress. Truck scales can use piezoelectric sensors using this method to determine truck weight! When a truck is situated on a piezoelectric scale, the pressure applied changes the actual voltage being produced by the scale sensors. These voltage changes can be used to determine the weight of the truck.

Walz Scale Can Handle All Truck Scale Needs!

Regardless of if you need to weigh a dozen trucks on a given day, or several hundred, Walz Scale can be your number one resource for all things about truck scales! We’d like to invite you to browse our inventory of truck scales, ranging from small portable models for quick and easy weigh-ins, all the way up to our TS-HD Series Truck Scale that can measure over 72’ in length and 14’ in width! In addition to selling these incredible machines, we can service and calibrate your existing equipment. We also offer rental equipment for testing the weight reliability of your truck scales. Contact our expert team of scale technicians today, and we’ll be on our way to keep your business running smoothly. 

If you have any questions regarding truck scales, our repair and calibration services, or how dependable truck scales can better serve you, please don’t hesitate to contact us today! We’ve been in this industry for a long time, and we can provide you with expert answers.