Digital Counting scales look at the weight of the items you place on the weighing platform and divide the weight by the number of pieces you entered, to compute the average piece weight (APW). This is how a digital counting scale displays the number of pieces or parts. The item(s) you are counting must be uniform in weight. No counting scale will ever work if there is a significant variation in the weight of the items. The larger the initial sample (100 pieces versus 5 pieces) the better results the counting scale can provide since it averages out any variations in the piece weights.
So, how do I know which counting scale is best for me? First, find a model that meets your capacity and accuracy requirements (remember the least amount of capacity you can handle is better). In fact, if you’re going to be weighing really light pieces, then possibly a balance with parts counting would be your best choice. Then, look at the features required for your applications (both now and in the future) such as computer/printer interfacing capability, battery operation, ability to connect a larger platform scale (remote scale), etc…