A Check Weigher is an automated weighing system for precisely checking the weight of filled pack and separate the underweight & overweight packs.

A Check weigher is a system that weighs items as they pass through the unit, classifies the items by preset weight zones, and ejects or sorts the items based on their classification. Check weighers weigh 100% of the items on a production line.
Typically, an in feed section, scale section, discharge section, rejecter and computerized control comprise the physical check weighing system.
“Simply stated, a check weigher weighs, classifies, & segregates items by weight”
An automatic check weigher incorporates a series of Belts Typically, there are three belts :
• An in feed belt that may change the speed of the package and to bring it up or down to a speed required for weighing.
• A weigh belt. This is typically mounted on a weight transducer which can typically be a strain-gauge load cell or a servo-balance or sometimes known as a split-beam.
• A reject conveyor to enable the out-of-tolerance packages to be removed from the normal flow while still moving at the conveyor velocity. The reject mechanism can be one of several types. Among these are a simple pneumatic pusher to push the reject pack sideways from the belt, a diverting arm to sweep the pack sideways and a reject belt that lowers. A typical check weigher usually has a bin to collect the out-of-tolerance packs.