Most states collect taxes based on the weight of the transported goods. Truck weigh scales stations are used for these tax purposes as well as to monitor the weight of a truck to ensure that it falls within the safety guidelines that each state has in place for its road system.
While the maximum allowable weight varies, a general standard is 34,000 pounds (15,400 kilograms). Weight is generally calculated in two measurements:
- Axle weight - The amount of weight conceded by each axle
- Gross weight - The shared weight of all the axles
Truck scales are built to handle a huge amount of abuse. For example, Perryscale provides a truck scale that they warranty to weigh trucks with a gross weight of 80,000 lbs (36,000 kg) each at a rate of 200 per day, 365 days a year for 25 years! Truck Scales are built away of steel, concrete or, in most cases, a grouping of both. The technologies used in the scales themselves vary. Let's acquire as appear at some of the more common forms.
In addition to the different scales used, there are at least three methods of getting the weight of a truck scales:
- One-axle - The most weighing method, a truck gradually drives across a single scale, stopping each time a set of wheels is on the scale. Once all the axles have been weighing, the total is added mutually.
- One-stop - A series of scales are used so that the whole truck can be weighed at once. The scales are usually connected to a single electronic controller that automatically combines the axle weights to get the gross weight.
- Weigh-in-motion (WIM) - A method that is gaining impetus, WIM uses a series of embedded sensors to compute the weight per axle as a truck drives over the sensor pad. Unlike the other two methods, there is no need for the truck to come to a entire stop while on the scales. In fact, some WIM systems are installed in highways so with the intention of all traffic is monitored at speed.