Weighing is a critical part of any process. It reduces raw material waste and production errors, boosting profitability.

When setting up an automated weighing system, it’s important to understand how the system works. This ensures that the system integrates seamlessly with existing manufacturing protocols and maintains optimum performance. This is especially true when implementing check weighing.

Identifying the Sample

The sample is the item or group of items on which a weight measurement will be taken. It must be identified and correctly measured to produce reliable results. If it’s not, errors will be introduced.

Identifying your sample isn’t just about its name, but how it is handled and recorded. A good sample management system is essential to track each weighing request, including the corresponding sample, date and time of weighing. This enables you to easily transfer weighing data to a database for further analysis or review.

In addition, your weighing area should be scrupulously clean to avoid contamination and prevent electrostatic interference. Any electrical devices should be placed away from the weighing chamber, and an antistatic mat can dissipate any static charges to protect against interfering with measurements.

Getting the Sample on the Balance

When weighing small samples, the right container size is important because an improperly-sized vessel increases the chance of spills. A good rule of thumb is to use a vessel that is no larger than the capacity of the balance.

Before adding a sample, the balance should be weighed with nothing on it to get its first reading. This process, known as taring, ensures that the weight measurements of the substance only include its actual mass and not that of the container or weighing paper used to hold it.

It is also important to keep the balance on a stable surface in a location that is free of vibrations and drafts. These factors can cause drift and inaccurate measurements in the results. In addition, a non-conductive weighing tray should be used as some materials carry an electrostatic charge that can affect the results of a weighing. Finally, fingerprints on the weighing container can add to its weight after taring so it is best to use gloves or tweezers when handling the container.

Recording the Readings

The accuracy of weighing readings depends on many factors, including the environment, balance, and reference standards. Good laboratory techniques and practices, along with a stable reference standard and balanced instrument, are essential for good mass calibrations. Air currents, lack of thermal equilibrium, electrostatic charges, magnetic forces, and abrasion can also affect the accuracy of weighing measurements.

To eliminate these errors, make sure the sample containers are clean and that they don’t touch the balance pan or weighing chamber walls. Keep the balance in a well-lit area and shield the location effectively against vibration, humidity, and temperature.

Another important step is the regular validation of weighing systems. This ensures that weighing processes and equipment meet strict quality standards, ensuring product safety and brand consistency. Automated weighing systems can further reduce errors by taking the guesswork out of manual interventions and eliminating repetitive tasks. This allows staff to focus on higher value activities and accelerates new hire training, reducing the risk of beginner mistakes.

Eliminating Errors

Weighing errors are largely unavoidable, but there are ways to reduce them. Start by identifying the types of human error that are common in your application, and pinpoint solutions with features designed to mitigate these issues.

Ensure your analytical balance is calibrated on a regular basis as specified in the laboratory manual. Calibration is particularly important when the balance has been relocated, before or after a power outage, and if the weighing environment changes.

Eliminate the risk of batch-to-batch variation by automating processes such as blending, filling, and batching. Using pre-programmed set points, automated calibration, and real-time data collection helps eliminate human errors and improve overall plant performance.