Anyone who has traveled between states by road would most certainly have seen truck weighing stations with big green colored signs that are either closed or open depending on the time of day you are passing by.
There are several different purposes that these truck weighing stations serve.
Their main purpose is to ensure that all trucks driving on the highway are not exceeding the maximum weight allowed a law that is imposed for safety reasons.
The second purpose that these truck weighing stations serve is to calculate the tax that is imposed on a certain truck.
This tax amount is also calculated based on the weight of the goods that are being shipped.
The maximum weight that these trucks are allowed to ship varies from one state to another but in the most common value is thirty four thousand pounds.
The third purpose behind having these truck weighing stations is to determine a rough estimate of the wear and tear the truck will be causing on the interstate highways.
This estimate is then charged a portion of the tax that the trucks pay and that portion goes to interstate for maintenance purposes.
The truck scales that are being used at these weighing stations are of several different types but one of the most commonly used and popular scale is the load cell scale.
This special scale uses steel or other types of strong materials to create each cell that goes onto the scale.
Then a strain gauge is fixed onto the scale, which basically has a wire that performs the tasks of sending electrical currents.
The current that is passing through the strain gauge is changed each time a weight is placed onto the cell.
The recorded amount of current is passed onto the junction box.
This junction box then uses this value to calculate the amount of weight that was put onto the scale and give out a reading.
The second most common type of truck scales being used in weighing stations is called the bending plate system.
This is quite common to the load cell scale except that the scale does not have cells to measure weight but have metal plates to serve the same purpose along with strain gauges.
The truck drives onto the scales and the amount of stress that is put onto the plate is calculated by the strain gauge and this information is then used to calculate the weight of the truck.