The Technology Behind Truck Weigh Stations

Truck weigh stations are obviously used to weigh trucks – hence the name – but most people don’t know why trucks need to be weighed. And even fewer know how weigh stations operate. Here is a brief look at three different truck weigh station systems and why they are necessary.

What are Weigh Stations Used For?

Weigh stations are primarily used by the United States to collect taxes on transported goods. The amount of taxes owed is determined by the weight. The stations are also used to determine whether trucks are within a particular road system’s safety guidelines. Most private vehicles are exempt from weigh stations, while commercial vehicles weighing more than 26,000 pounds, or having three or more axles, are required to pay fuel taxes.

Load Cell Systems

The most popular weigh station system is the load cell system. It is comprised of steel or concrete, and has multiple strain gauges embedded within. These gauges transmit electric currents to a junction box, which measures the variance in the current and calculates the weight on the scale.

Bending Plate Systems

The bending plate system uses metal plates with attached strain gauges. When weight is applied to the scale, the strain gauges measure the amount of stress on the plates and calculate the amount of weight the scale is supporting.

Piezoelectric Systems

These systems use a number of piezoelectric sensors embedded in conducting material. Weight is applied to the scale and the pressure changes the amount of electrical charge in the conductors. Sensors then measure the change in voltage and calculate the weight of the load.