What affects the accuracy of the check weigher?

CHECKWEIGHER ACCURACY: WHAT AFFECTS IT?
The accuracy of any manufacturer's CheckWeigher can be influenced by various conditions. There are methods to compensate for or eliminate these problems. When deciding to purchase a CheckWeigher, consider whether there are any factors in your facility or with your product that could affect the accuracy of the CheckWeigher.

ENVIRONMENT Environmental effects play a role in the accuracy of all scales. Some CheckWeighers are better equipped than others to handle challenging environmental conditions. Several environmental factors can affect CheckWeigher accuracy. Some load cells may not handle temperature fluctuations well. If the strain gauges in the load cells are not protected against humidity and disruptive external factors, extreme temperature and humidity conditions can damage the load cell's accuracy. Particles and dust falling onto the scale can alter the CheckWeigher's calibration. If these particles fall continuously, the CheckWeigher may need constant resetting. Protecting the scale section from the external environment or creating a reasonably clean production area around the CheckWeigher can significantly improve efficiency. Any vibration is perceived as noise or unwanted signals on the scale.
This can be caused by a nearby hopper, a press right next to it, or another conveyor connected to the CheckWeigher line. Many CheckWeighers can automatically filter out external noise. However, for optimal performance, the CheckWeigher should be isolated from environmental vibrations.
Airflows, as well as residual particles, can also affect the CheckWeigher display. Especially in the pharmaceutical industry, where very high-precision CheckWeighers are commonly used, preventing drift is critical. Even if the airflow is kept to a minimum, taking precautions against potential drift over time can be beneficial. If you have a high-precision scale, try passing your hands over the scale platform without touching it. You will notice a weight change. The same will happen in conditions 0-5. Electrical noise (interference), such as electrostatic discharge and Radio Frequency Interference (RFI), can disrupt the CheckWeigher display. RFI can be generated by devices such as paging devices, mobile phones, and radios. Creating a static field on the scale can quickly be visible on the scale weight and cannot be filtered. Static fields can be created by the product passing through the scale or by the machine.
Corrosive environmental conditions can damage a load cell or other scale components. Consider the products in your facility and your cleaning procedures.
CheckWeighers can be used for various products. Stainless steel parts are highly resistant to continuous contact with water or challenging environmental conditions. Other parts can be coated with protective paint, but this may not provide continuous protection in challenging environmental conditions or wet environments. Some load cells are made of aluminum. They work well and are cheaper than those made of stainless steel, but these load cells are not designed for contact with water or corrosive materials. They should not be used even in environments where corrosive effects may occur, even rarely. One of the most common reasons for low accuracy values is incorrect use of the CheckWeigher. Without realizing it, a person working with or around the CheckWeigher can damage it. Some common examples include stepping on the weighing platform, applying excessive load to the load cell for any reason, shifting the weighing belt, and cleaning the CheckWeigher incorrectly.

TIPS TO PROTECT YOUR CHECKWEIGHER FROM THE ENVIRONMENT • Use a load cell with well-protected strain gauges.
• Keep your workspace clean or protect your scale from particles that may fall.
• No other mechanical system should touch the CheckWeigher.
• The entire CheckWeigher should stand firm.
• Isolate the CheckWeigher from other high-vibration machines.
• Isolate the CheckWeigher from wind and air currents, or take protective measures if necessary.
• Ground all parts and protectors touching the scale.
• If necessary, de-ionize the static electricity of the products.
• Protect the CheckWeigher from radio waves.
• Protect your line from voltage surges.
• Choose a mechanism suitable for the conditions of your facility.
• Use a load cell suitable for the environment.
• Train all personnel related to the CheckWeigher system. This includes operators, mechanics, maintenance staff, and production engineers.
• Perform routine maintenance and cleaning of the CheckWeigher according to the manufacturer's instructions.

PRODUCT An ideal product for the CheckWeigher should have characteristics such as passing through the CheckWeigher in a single and smooth package, not changing shape, not swinging, or vibrating. The viscosity of a liquid product can affect the weight reading process by the CheckWeigher when the product swings or vibrates.
The more unbalanced the content of a package passing over the scale platform, the more time the scale needs to read the correct weight value. There are many options to ensure product stability. Loose products falling onto the scale, like other falling particles, can hinder the correct display of weight. Most CheckWeighers periodically reset the scale when the line is empty, but this is not always possible. Zero reading allows for the calculation of fallen products, but it still may not catch every discarded product. For example, when an open bag of flour passes through the CheckWeigher, the flour in the bag can spill onto the platform. This spilled material may not be cleaned until the next package arrives. The CheckWeigher does not have enough time to reset before the next product arrives. Even if the second package has a lower weight than required, the CheckWeigher can accept this product because it can see it along with the material left on the scale.
A small and wide package is always more stable than a long and thin one. Shampoo bottles are often considered unstable due to the ratio of their heights to widths. A shampoo bottle can tip or sway when passing through the scale or transferring to another conveyor.
A swinging or tilting irregular product will affect reading accuracy because it will never stay perfectly flat on the scale. A sorting rail used before and after the scale can help but cannot touch the product on the scale. The surface