Check Weighing

·       WPL Industries B.V. has developed a range of solutions and products to cater for high speed measurement and accurate detection of over- or underweight in check weighers.

The unique way of measuring, high speed and high resolution, offers outstanding suppression of undesirable dynamic effects. Check-weighers are automated systems designed for checking the weight of packaged commodities for the purposes of internal control and external trade application. The checking process is usually found at the end of production processes in any given industrial process flow. 
For external trade applications, legal requirement is obligatory. The worldwide O.I.ML. (International Organization for Legal Metrology) recommendation R51 outlines these rules while the MID (Measurements Instruments Directive) is Europe specific. Two types of check weighing can be distinguished: 
◦ Category X: only the package content is defined; this is needed for content price calculations.
◦ Category Y:  the package content is determined and compared with defined tolerances for purposes of acceptance or discard of a package. Such tolerances are typically mandated, similar to the e-mark registration.  Packages weight outside of the given tolerances, are automatically removed from the process line. 
Both categories can be either static or dynamic. In the latter case, the package is in motion, for example on a conveyor belt. This will typically have an adverse effect on the weight due to accelerations and vibrations of the mechanical parts.