Conveyor scales are mass measurement devices mounted on conveyor belt systems designed to weigh the moving load on the conveyor and to return a range of readings such as average load weights and load totals for a set period. The scales used on large, flexible belt systems are usually mounted between the rollers on the conveyor frame between the transport and return runs. Those designed for use on smaller, roller conveyors consist of scale units complete with roller sections that are added to existing installations at pre-determined points. The scale readings are sent via cable runs to a controller that assimilates and stores the readings allowing them to be displayed or printed on a real-time basis or at the end of a metering period.
Conveyors of various descriptions form the material transport backbone of a large proportion of industries around the world. In most of these industries, keeping track of how much material is transported by the conveyor system over any given period is a critical part of the operation. It allows operators to access system efficiency data, quantify losses due to spillage or pilferage, and is often an integral part of many companies' billing or inventory systems. This information may be accumulated in a number of ways, the installation of conveyor scales being one of the more common. These devices weigh conveyor loads on a real-time basis as the material crosses the scale's load cells and are available in models suitable for most conveyor types.
Flexible conveyor belts consist of continuous rubber belts that run on sets of regularly-spaced idler rollers and are generally used for long conveyors transporting loose aggregates such as various ore products. The section of belt on the top of the loop is known as the transport run with the lower, unloaded section known as the return run. Conveyor scales designed for this type of conveyor are often configured as drop-in idler roller sets that include an integral load cell and interface. As the loaded transport run passes over the load cell, it calculates the weight of the load on a real-time basis. Other types mount between existing roller sets and feature a separate load cell that presses against the transport run.
Roller conveyors are generally used inside factories or warehouse facilities and are used to transport loose unit loads. The conveyor scales used on these types of conveyors are usually free-standing units that include a section of relevantly-sized roller conveyor. They are placed in the existing conveyor run where they become part of the transport chain. Other roller conveyor scales take the form of standard conveyor frame members which can be added to an existing installation at any point. Both types of conveyor scale will generally feed their outputs to a local or remote station where the measurement data is viewed immediately or stored for later use.