Although conveyor scales and checkweighers appear to be very similar, they are two entirely different entities. The ultimate difference between them is that one is a system and one is a component to be part of a system.
The in-motion checkweigher is defined as a system because it is formed of several components that form a single working unit. It is composed of an infeed conveyor, a conveyor scale, and an outfeed conveyor with some sort of diverting device, all as one unit.
The sole purpose of a checkweigher is to take a weight and check that against a user-specified range. If a product is inside this range, it passes through, down the conveyor. If not, the divert rejects the product onto another conveyor or container to be disposed of or reworked. This is all decided by software that is unique to the checkweigher.
Notice that a conveyor scale was just a single component of the checkweigher itself. A conveyor scale simply generates the weight of the product as it passes over. This makes it versatile.
A conveyor scale can be connected to a sortation system or an automatic labeler quite easily so that these systems can receive accurate weight information. Simply put a conveyor scale is just that – a scale that weighs products as it is conveyed over the scale’s live area, without stopping.
A checkweigher is more akin to a combo of conveyor scale and sortation system, except the sortation system only has two options: pass or fail.
As an example of how they differ in practice, let’s look at a producer that uses fixed weights and another that labels by weight (catch weight). For the former, a checkweigher is going to be far handier than just a conveyor scale because it can be programmed to reject any product that is below the minimum weight. Likewise, a conveyor scale is more valuable in the latter because it can link to a weigh price labeler and is capable of relaying individual weights to any number of systems.
The difference isn’t always obvious, but it is important to know the industry lingo when it comes to automatic systems.
It can save you a lot of trouble in the long run!
See our Checkweigher Conveyor Scales
When you are in the market for conveyor scales, you may find it difficult to know exactly what to look for, and investing in a new conveyor scale can be a big deal.
Fortunately, there are several areas that you can focus on when comparing your options.
Structural integrity is a prime consideration for conveyor scales.
For example, stainless steel can hold up to almost any wear that you throw at it and can be made food grade, so it isn’t contaminating products.
On the other hand, less resilient metals like aluminum can still live up to certain processes expectations and are more affordable. Just look at our Ecoline™ series of conveyor scales as an example.
Belting is something else to keep in mind.
Do you handle food? There are specific types of conveyor belt for food grade.
There are different belts for a variety of different products, so it is important that you know the whole spectrum of products that your conveyor is going to be working with.
Of course, you should also know the general weight range of the product as well.
The scale’s weight capacity has to be able to handle your largest products.
We offer NTEP-certified WeighMore® scales that vary from 10 to 200 lb capacities to fit any of your weighing needs.
Just as important as the capacity is the division size for the scale.
The division size tells you a lot about the precision of your measurements.
A scale with a smaller division size (more divisions) is more likely to have a precise weight reading than one with fewer divisions.
The scales mentioned above have 2000 NTEP divisions.
Last, but not least, you need to consider throughput. Throughput is one of the most important factors for some plants, and you should always ensure that your conveyor speeds and belt selection can move product at the speeds you need.
Our conveyor scales can run all the way up to 380 feet per minute.
It is always good to be informed when picking conveyor scales, but we recommend that you get in touch with us.
We have a full product line which is guaranteed to have an answer to your conveyor scale necessities, and we also have a dedicated, qualified staff who is ready to work with you to make sure all of the pieces fall into place.
We build quite a few conveyor scales for various plants, and it is important to remember that no two plants are the same.
There are different spatial and design constraints from plant to plant, so you have to be ready for anything. A good example of this is a plant that requires more floor space than a conveyor scale might allow.
There are also plants with multiple conveyors and sortation systems that create a complex network of crisscrossing conveyors.
It can be difficult to place your standard conveyor scale in some of these places. We are willing to adapt our standard designs to navigate troublesome areas.
We have installed some conveyor systems that are essentially inverted.
Our typical setup has the scale and motor mounted directly below the conveyor, but we can set it up so that these components are actually above the conveyor.
We mount the conveyor portions to a framework that goes up and pulls down onto the load cells for the exact same result as you would find with a regular conveyor scale.
Why would you design a conveyor this way?
One good reason would be because you use a complex sorting system that uses drop-down diverts to sort to other conveyors below the main line.
Because of space constraints, these conveyors might have to pass right underneath the conveyor scale. This makes it necessary to move the components from underneath to a location where they won’t be in the way.
Another reason for using a conveyor like this would be the need for movement space underneath the conveyor scale.
If you have an elevated conveyor scale, moving the scale and motor components from the bottom of the conveyor to the top could allow more clearance for traffic underneath. This could prevent a dangerous forklift collision for an unaware operator.
We have the ability to create conveyor scales in many shapes and forms. They can interface with a large range of equipment making them one of the most versatile pieces in a plant.
If you need a conveyor scale, but don’t see how it could fit in your process, we would love to work with you to make that need a reality!
In-motion conveyor scales are an important part of many production plants.
There are many things to consider when looking at purchasing an in-motion conveyor scale.
For those who are not familiar with them, it might be a little intimidating to know where to even start. Here a few tips to help you select an in-motion conveyor scale that will fit your application.
- Know the environment the scale will be placed in. Will it be subjected to any high-pressure washdown or chemicals? If so, a stainless steel in-motion conveyor scale will more than likely be what you are looking for. Will it be inside and just exposed to dust and normal conditions? If so, an aluminum conveyor scale will fit the bill.
- Know the type of product the scale will be weighing. The variety of products weighed in-motion is nearly endless: tubes of toothpaste, boxes of cereal, pork loins, letters, etc. The list could go on and on. There are several questions that directly relate to the product. Is the product heavy or light and what size is it? Conveyor scales are made in different sizes to weigh all types of product. Will the product be raw or unprocessed food? If so, it may need to be manufactured to meet certain requirements for being able to clean it or the materials it is made from. The type of product being weighed is extremely important in being able to select the proper scale.
- Know the division size needed for the scale. For some applications, division size may be quite large; maybe you only need to know the product weight within a pound or two. For other applications, scale division size may need to be extremely small. In some applications, division size may need to be as small as 0.1 gram or less.
- Know the throughput required. This requires being able to accurately estimate the number of products per minute or hour that will be weighed. Additionally, an important consideration of the throughput is how the product is spaced coming into the conveyor scale.
- One last important consideration is whether the scale will be used for legal-for-trade applications. This applies when the product weight that the scale gives is the weight that is used for pricing or labeling the exact product the consumer will buy.
Knowing these 5 things will help you to be able to select the conveyor scale that will fit your needs!
Most of the applications that we discuss focus on the meat/food industry because it is a good fit for our legal-for-trade stainless steel scales and automation systems, but there are plenty of reasons that you might need a quality scale.
A notable shipping company decided that their operations could seriously benefit from the use of several conveyor scales.
Shipping companies go around and gather packages from various places and bring them to a central hub where these packages are weighed, sorted, and placed on delivery trucks to be carried to a different location.
Normally, with shipping, the shipper is responsible for weighing the package and paying that cost up front, but that weight isn’t always accurate.
They use scanners to identify each package before crossing over our conveyor scale.
Once it crosses over our conveyor scale, the weight information is then tied to that package.
If the weight paid for by the shipper doesn’t match with the weight from the scale, they can add charges to the account.
It might seem like a little amount of money if the package is off by a bit, but these hubs handle thousands of packages per day, so that could start to add up for them.
Also, when you factor in things like maximum safe loads on vehicles and airplanes, it is much safer for the shipping company to know the precise weight of everything rather than relying on the nominal weight.
The conveyor scales that we provided them had to be highly accurate to ensure that they weren’t losing money on these packages, and they had to be durable enough to handle thousands of packages apiece on a regular basis.
This was no problem with the level of quality that we put into each conveyor scale.
If you would like to see what a quality conveyor scale could do for your business, get in touch with us today!