How to Count on Your Digital Counting Scales

There’s no doubt that using digital counting scales can save time and money.  Easier to explain is time, because these accurate tools can do in seconds or minutes what it would take hours to count by hand.  That in itself saves time, but if the scales are also used in inventory control they can help identify unusual movement of product out of storage.  Who is taking the product and why?

As good as they are – and products such as Kern’s CXB counting scale are examples – when using them one must keep in mind the old computer admonition “garbage in, garbage out.”

These scales can weigh but they can’t think.  This requires operators to establish uniformity of weight across the products being weighed.  What can throw this off?  Well, some products in the batch may have burrs or other imperfections that will lead to inaccurate counts.  In fact, anything that causes an anomaly – even varying moisture content or lubricant coatings – can throw off the count.  In such instances the smaller the parts being weighed the more inaccurate the count can be.

Most scale manufacturers offer suggestions on minimizing anomalies by hand counting out a sample lot then telling the scale how many parts are being weighed.  This establishes the average piece weight.  Once the scale knows the average piece weight the rest should be a piece of cake.  Load the scale with parts and it will tell you how many parts you have loaded.  That should convince you of the value of a counting scale.

Here’s a tip: the more pieces you use to establish the average piece weight the more accurate your readings will be.  This is because the scale averages out over a larger number.

Useful Bells and Whistles

Counting scale manufacturers offer a number of features that add to the utility of these tools.  I particularly like Kern’s CXB because it offers helpful features in a rugged but realistically priced entry-level scale.  In addition to a counting resolution of 30,000 points it has a memory that adds up individual counting operations to present the total weight and total pieces.  Moreover, if the operator is filling an order for X pieces, the unit can be programmed to sound an audible signal when that count has been reached.  This makes it really easy to fill a container to a target quantity.

Two other features are also helpful in terms of achieving and maintaining accuracy: automatic optimization of the reference weight gradually improves the average value of the piece weight, and the scale can be easily calibrated with external weights using a built-in calibration program.

Readout is painless thanks to a large LED display that turns off after 5 seconds when the unit is operating in its energy saving mode.  The internal rechargeable battery pack gives about 200 hours of service and provides notification of the charge condition.  Recharging is accomplished in about 8 hours.

Not bad for an entry-level counting scale backed by a three-year warranty.


What experiences have you had in using counting scales? Have they been used to identify discrepancies in inventory?  What are the smallest or lightest pieces you weigh and how accurate are your readings?

About Rachel Kohn

So how did an MIT Ph.D. end up selling refrigerators? When I figured out that a lot more scientists buy lab refrigerators than innovative leading-edge instruments. I hope that my many years of lab experience will help you find the right equipment for your work. Before co-founding Tovatech I worked in business development and project management at Smiths Detection, Photon-X, Cardinal Health, and Hoechst Celanese. And before that I spent 12 years as an R&D chemist at Hoechst Celanese and Aventis working on advanced drug delivery systems, polymer films and membranes, optical disks, and polysaccharides. Some day, eventually, I’ll make enough money to develop an innovative technology that will change the world. Read More