A conveyor scale is a live scale supporting a section of conveyor. It provides weight data of the items which cross it for various activities. This data may be utilized and incorporated with label printing and application.
In-motion conveyor scales function by averaging multiple weight measurements as an item passes across the scale section. Photo eyes are positioned so as to initiate and terminate the averaging while an item is solely on the scale section. This of course indicates the need for product spacing. There can be no accuracy if more than one item is on the live scale section at the same time. For this reason, there are often methods introduced to induce the spacing required for only one item crossing the scale at a time.
Sometimes conveyor scales simply accumulate total items and weight volume over a period of time for accountability and record keeping. Some conveyor scales accomplishing this activity are referred to as flow scales, as they monitor the weight volume of materials flowing across the scale in a continuous stream for a measured segment of time per revolution of the conveyor belt as determined by an encoder device. Obviously this is a specific type of conveyor scale.
In contrast to the scale activity mentioned above, a checkweigher scale provides the functionality of setting weight specifications for rejecting or diverting items accordingly. As individual items cross the live scale section, the weight of the individual item is checked against the established set points for respective action after leaving the scale. There may be several different points forward of the scale at which a product may be diverted according to program activities in response to the weight set points. Items might be diverted for reworking because of over or under weights according to targeted values. Thus the items crossing a checkweigher scale are manipulated according to the set values for respective activity.
In conclusion, a conveyor scale provides weight information for utilization and application, where as a checkweigher results in material manipulation according to variable weigh data and set points established by the user.