Checkweigher More than a Fancy Word for “Scale”

Ready made plastic trays

One of the most common American pastimes is grocery shopping. Every week millions of Americans pile into their favorite local grocer and fill their carts with produce, meat, bread, snacks, and various other things. This ritual is so common it’s easy to take for granted the processes which take place to get all those products to the store and eventually your home. When it comes to items like packaged meat, how do stores receive the right amount to satiate the needs of the customers? And how is it that you rarely ever find a pesky bone inside the meat you purchased (even if one pops up once in blue moon)?

What are Checkweighers?

The term “checkweigher” isn’t all that common, and seems like a convoluted, whimsical way of saying “scale.” But checkweighers aren’t merely scales, though this is a major aspect of its function. Checkweighers are typically automated machines that include a conveyer belt, scale, and sometimes other add-ons like food metal detectors and x-ray food inspection devices.

Essentially, the job of a checkweigher is to ensure a product is properly measured, packaged, and safe for travel and consumption. Depending on the product and its desired weight per unit, an operator will set the specifications of a checkweigher to accept products which fall in a certain range of weights. For instance, a company might need its product to be no more than 1 lb. and no less than .95 lbs. per unit. If the checkweigher detects that the unit falls within this range, the conveyer belt allows the product to continue down the line. If it detects that the unit is outside this range, it is rejected and redirected for inspection and correction.

Many checkweighers are also capable of learning, in that they can increase or reduce converter belt speed depending on the amount of units being rejected or accepted. In other words, if too many products are being rejected, there might be a pile up of too many units for personnel to take care of in a timely manner. The machine can slow itself down to allow more time and avoid any unnecessary stacks of units.

More than Weight Measurement

While checkweighers are extremely accurate and fast in their weight measurements, they are also capable of inspecting a product even more closely. For instance, some checkweighers are equipped with or placed near x-ray machines and metal detectors. For products such as beef and fish, these devices are used to detect any hazardous or unwanted material inside the item. Some newer state of the art x-ray machines can even sense poultry bones and other material as tiny as 1.5 millimeters small!

As far as metal detection goes for food, there are three primary kinds of metal these machines will look for: ferrous (containing Iron), non-ferrous (without Iron), and stainless steel. While it’s not all that common for food products to contain these metal contaminants, sometimes small pieces of machinery can break off and enter the food or packaging during production. In order to follow federal food safety guidelines, food companies must ensure that their products don’t contain any of these unwanted and hazardous metal materials.

After the Checkweigher

The checkweighing process occurs at the tail end of production, shortly before being sent to the customers and retailers. The products that don’t pass the checkweigher are reexamined by personnel and either corrected or thrown away depending on the type of problem. Those that do pass are conveyed down the line to be shipped. After this, they eventually make their way to your local grocery store, where you can rest assured your product is the right size and safe to consume.

Any time a customer finds something like an unwanted bone in their meat, chances are there was an error in the checkweighing process or personnel made a mistake and approved the product for shipment when it should have been left behind. In any case, these occurrences happen less frequently as these technologies improve and can detect smaller and smaller things. So the next time you pick up some chicken at the market and enjoy a nice meal that evening, take a second to appreciate all the ingenuity of engineering that went into getting it conveniently to you and your home.