(Editor’s Note: This is an online-only article attributed to the August/September 2017 issue.)
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Weight measurement is extremely critical for product consistency and to improve the efficiency of the processes, thus making weighing systems a must-have equipment in every food business. There are several options available in the market and it can get quite overwhelming to choose the one that would suit your requirements perfectly. Consider the following factors to help you choose the right weighing systems and food weighing scales for your food business.
- Principal use. What do you need the weighing systems for? Is it for weighing liquids or solids, would you use it to weigh large quantities or small, do you want to weigh uniformly sized objects or small parts, would you need to control conditions such as cooling, heating, or mixing inside the weighing vessel? The first step is to identify the primary use of the weighing scale.
- Ability to customize. Check if you can customize scales like conveyor scales with additional features to enhance flexibility, improve functionality, increase protection, etc. You must consider if your scales require explosion protection, interfacing ability with a computer network, an internal calibration software, wireless connectivity, multi-language displays, backlit display for dimly lit areas, etc. Customize the scales accordingly to address those needs.
- Capacity. Determine the largest possible load you require the scales to handle. Check if you need an overload protection, estimate the overall footprint of the scale and consider how the items being weighed would fit within the weighing area. It is generally recommended that you use a weight balance for samples from microgram levels to about 10 kilograms (kg) and load cells for samples from 10 kg to a couple of metric tons. Stress will be minimized, greater accuracy will be achieved, and there will be less damage to the sensitive internal electronics when the weighed quantities lie in the range of the unit’s specific capacity.
- Accuracy. In terms of weighing, accuracy can be considered as a combination of various factors, such as its ability to read the smallest mass change over time, reproducibility, the degree of variance in accuracy over the weight values within the scale’s capacity, and a difference between measured weight and true weight due to environmental variances.
- Material. It is important to consider the material of the weighing system. You can choose from the basic materials such as carbon steel, aluminum alloy, galvanized steel, and aluminum coated steel, however, these materials are ideal for conditions where corrosion-resistance and cleanliness are not critical. Consider AISI-304 and 316 stainless steel where high cleanliness, chemical or environmental protection, and hygienic design are paramount.
- Environment. Consider the environmental conditions where you would employ the weighing systems. Environmental conditions such as large temperature fluctuations, magnetic fields, vibrations, humidity, air currents, electrical interference, and corrosive medium can affect weighing, especially at higher resolutions. Also check if a particular environment requires specialized padding, protective covers, or frequent calibrations.
- Price. Consider the price of the scales but don’t make a selection based solely on the price. Remember that it is not necessary for the most expensive weighing systems to always be the best choice for your requirements.
- Installation. Place the scales in a permanent location and connect them to a peripheral equipment while installing them. The readability of the measurements and the resolution must be set. Perform an initial calibration after the installation. If you are installing multiple load cells on a large vessel, perform a corner load test to ensure an even weight distribution. Ideally, you should not move the scales from their point of use once they are installed.
- Calibration Requirements. Regular calibration of weighing scales is absolutely necessary as daily use would cause the accuracy of the scales to drift to a certain extent. Ensure that a series of certified test weights are used to record the results. If the displayed results do not correspond to the test weight, you must make manual or automatic adjustments to correct the drift.