Checkweigher FAQs

Welcome to our Checkweigher FAQs page. Here, you’ll find answers to commonly asked questions about checkweighers.

How does a checkweigher work?

A checkweigher generally comprises of a common frame with three conveyors:

  • Infeed Conveyor
  • Weigh Conveyor
  • Outfeed Conveyor

A product being weighed goes through the following steps:

1) A product is presented to the checkweigher from a customers conveyor to the infeed conveyor. The conveyor
speed on the infeed conveyor is matched to the weigh conveyor.
2) The product is then transferred from the infeed conveyor to the weigh conveyor and product is weighed as it
moves across the weigh conveyor
3) Product is then transferred to the outfeed conveyor and then transferred onto customers exit conveyor. If an
incorrect weight has been detected it is ejected from the line using a reject system

Are checkweighers able to weigh different product sizes and weights?

Checkweighers can weigh a variety of different products and weights. We can tailor the machines specification to suit
your product. Different conveyor sizes, constructions and designs can be selected depending on your application.

How accurate are checkweighers?

Our checkweighers are designed to provide high accuracy and repeatability at a variety of applications. Typical
machine accuracy is +/- 0.5g with accuracies of +/- 0.2g achievable in certain applications.

Can a checkweigher handle high-speed production lines?

Our checkweighers can be designed to meet the requirements of any production lines. Our standard machines can
usually weigh products from 10 packs per minute up to 180 packs per minute. For higher speed applications we have a
variety of different high speed machines we can offer depending on the application.

Can a checkweigher detect and reject underweight or overweight products?

All Driver Southall checkweighers will reject any products that are classified as an underweight product. The
checkweigher also has the option to reject products which are over a certain weight. These rejects can be into the
same reject bin or optionally they can have separate reject bins.

In addition, when partnered with a metal detector or x-ray system the checkweigher can also reject products that
have been classified as a contaminated pack.

Can a checkweigher be integrated into existing production lines?

Driver Southall specialises in providing customers with machines that meet their exact requirements. Our machines
can be designed to integrate into existing production lines, or where not possible, we can engineer bespoke solutions
to suit your exact requirements.

Do checkweighers require regular calibration?

To ensure checkweighers are working to their optimum, the checkweighers should be calibrated regularly by an
external contractor using weights calibrated to the national standard. The calibration should include checking the
machine with a range of weights the full span of the machine’s capacity.

We recommend customers having their machines calibrated twice a year, but this may change depending on the
machine’s location, required accuracy and age.

Are checkweighers easy to operate and maintain?

All Driver Southall checkweighers are designed with simplicity and function in mind. The touch screen displays are
easy to use, and menus are easy to navigate. The machine is designed to be easy to maintain with all conveyor belts
being easily removable and replaced quickly.

Why are checkweighers used by food manufacturers?

Checkweighers play a vital role in food manufacturing by ensuring products produced a compliant with the national
regulations. Food manufacturers must adhere to strict laws that ensure weights stated on products are the correct
weight as stated on the packaging.

What is the difference between minimum weights mode and average weights mode?

Minimum weights and average weights legislation are two different approaches used in regulating product weights in
various industries, including the food industry.

1. Minimum Weights Legislation: Minimum weights legislation sets a minimum acceptable weight for packaged
products. Manufacturers must ensure that their packaged products meet or exceed the minimum weight
requirement specified by the legislation.
2. Average Weights Legislation: Average weights legislation allows for some variation in product weights within a
specified tolerance range. Instead of specifying a minimum weight, this approach focuses on the average weight
of the product over a batch or production run. The legislation sets a maximum allowable deviation from the
stated weight, allowing manufacturers to have some flexibility in meeting consumer demand and
accommodating natural variations in the production process.

More information on average weights legislation can be found here.

How can a checkweigher contribute to cost savings and waste reduction?

Checkweighers not only improves operational efficiency and product consistency. By accurately measuring the weight
of products, checkweighers help ensure that the correct amount of product is packaged, minimizing overfilling and

In addition, checkweighers enable manufacturers to identify and address production line inefficiencies promptly. If
deviations from the specified weight are detected, adjustments can be made to optimize the manufacturing process,
such as adjusting fillers or fine-tuning production parameters.

Can checkweighers be washed down?

All our machines unless stated otherwise are protected to IP65 as a minimum. Most of our machines are protected to
IP66 and are suitable for direct low pressure washing. For more information on how your machine should be cleaned
please refer to the user manual.

What is the typical lifespan of a checkweigher?

Driver Southall manufacture our checkweighers to thrive in production environments with machines in production
over 30 years old. Whilst it is inevitable that some parts will become obsolete over time we offer support to all our
customers with electrical upgrades available for older machines.