Weighing is a key component of every production process, from weighing raw materials at the receiving dock to ensuring that final products look and taste the same in each batch. Achieving optimum performance requires careful execution of standard weighing procedures and consistent practice.
Direct weighing involves placing the container on the balance and reading its mass. To obtain accurate results, the balance must first be zeroed (read as 0.000) by taring it.
Accuracy
Weighing is a critical component in many manufacturing processes. Inaccurate weighing can cause products to be out of specification, which costs time and money to correct. Accurate weighing reduces waste by accurately dispensing materials and contributing to stringent quality control measures.
The accuracy of a weighing system depends on the load cells and the system’s overall design. A system that is not stable and/or abrasion resistant can damage the load cell(s), degrading its overall accuracy.
Another important factor in ensuring accurate weighing is that the sample is homogenous and that it is size reduced. For example, a watermelon is too large to be weighed on an analytical balance, but it can be sized into a cube which can be easily weighed.
It is also important to understand the difference between accuracy and precision. Accuracy is the closeness of a measurement result to the true value or standard, while precision refers to the repeatability of measurements over long periods of time.
Efficiency
The weighing process in food production is critical to ensure the quality and consistency of finished products. Even the smallest deviation can throw off a product. Accurate weighing means the correct amount of ingredients or components is used each time.
When using an analytical balance, chemical substances should never be added directly to the pan or weighing paper. This can cause the chemicals to dissolve or interact with each other in ways that change their mass. Instead, the weighed substance should be placed in an appropriate container that can be tared and then added to the pan.
Weighing systems that are built right into construction equipment provide accurate payload weight and distribution to maximize the use of your fleet. These systems track materials as they move through a construction site, helping project managers save money by optimizing each load. These systems also enable compliance with governmental regulations on material traceability and accountability through a reliable weighing process, regular calibration, and maintenance.
Safety
Whether it’s in a laboratory or on a weighbridge, the handling of dangerous chemicals requires special safety considerations. PPE (personal protective equipment) such as gloves, goggles and lab coats help protect operators from chemical exposure. Containment tools like fume hoods and safety cabinets minimize environmental exposure.
If direct weighing is used, the balance must be carefully zeroed (reads zero with nothing on the pan) to ensure accurate results. It is a good idea to use tweezers instead of hands when placing an object directly on the balance pan to avoid cross contamination.
Taring is a process that adds an object to the pan and then subtracts the weight of the empty container to display the net weight. Tare management functionalities are often available on balances to simplify this procedure and help reduce manual effort.
Maintenance
The weighing process requires careful maintenance. For example, a hopper needs to be tested with the actual material it will handle during normal operations. This involves simulating loading and discharge, comparing the results with expectations, and making adjustments to the system as needed.
Large weights of lower tolerance classes need to be handled with care to avoid damage to the laboratory facilities and the balances themselves. Special hoists and crane hydraulic systems, as well as expert laboratory personnel, may be required to gently set large weights onto large comparators in a safe manner.
Objects and materials should never be handled with bare hands, as they can absorb moisture and cause inaccurate readings on a single-pan analytical balance. Additionally, all objects and materials should be carefully cleaned before being placed on a balance. A clean weighing paper should also be used, as it will eliminate any air currents that can disturb the readings. The balance should always be “tared” to read 0.0000 g, before beginning any formal weighing.