The weighing process is crucial in the manufacture of analytical instruments. Its accuracy and precision are critical to the quality of the products. However, there are a number of problems associated with manual weighing of small samples. Here are some tips to help you automate this process. First, decide who will perform the weighing process. It may be a CRO or an internal contractor. Different permission levels can help manage authorisations and options.
Weighing is the most accurate measurement method. It can measure dry bulk materials, flowrates, and other materials without volumetric correction factors. It also doesn’t involve contact with the material. As a result, it’s the widely accepted method for weighing packaged products. This process is suitable for measuring dry bulk materials and corrosive materials. This technology also prevents contamination. However, it can also damage the weighing system.
In a typical batching process, load cells are used to monitor the weight of up to 400 pounds of material. This requires three 200-pound load cells suspended from the hopper. This configuration allows for vessel expansion and contraction caused by changes in temperature. The load cell monitors the weight of the material often enough to detect even minute changes. Temperature effects on the output of the process are also taken into consideration. The process should be budget-conscious.
Manual weighing processes are indispensable in many facilities. The human element adds flexibility to these systems, allowing companies to adapt quickly to changing markets. However, manual weighing has several inefficiencies. Automated process control systems such as the Mettler Toledo ICS series reduce these variables while still preserving the flexibility of manual processes. ICS mode, for instance, allows rapid portioning without manual zeroing. The ICS mode eliminates the need for tare weights and keys, which can decrease accuracy.
Automatic dispensing systems also known as loss-in-weight are a convenient way to accurately weigh chemicals. This system uses load points and platform scales to sequentially fill empty containers, stationary vessels, and process equipment. The net weight of the material dispensed is displayed. Several speeds can be used, ensuring accuracy of measurements. This process is also useful in pharmaceutical production. When using liquids in process equipment, it is important to keep the weighing process accurate.
When weighing small amounts of samples, it is essential to use disposable gloves, a head cap, and a face mask. To avoid any possible contamination, you should also record the result directly in your lab notebook or print weight slips. These weighing processes are critical to the accuracy of your analytical determinations. A clean and dry balance is essential for accurate results. For this process, you should avoid using butter paper, which introduces errors.
Temperature changes affect the weighing process. In some cases, it can make load cells sensitive to temperature fluctuations. Fortunately, most load cells have temperature compensation. However, outdoor weigh vessels can experience huge temperature changes. The daytime temperature can heat them up quickly, while nighttime temperatures may be cold and vice-versa. Moreover, seasonal temperatures can cause the weighing process to be inaccurate. To avoid this problem, you should make sure to use temperature-compensated load cells and temperature-sensitive mounting hardware.
Another important factor to consider is the environment. A pressurized plant floor can have substantial impacts on the weighing process, as it differs from the ambient pressure floor. To minimize this effect, it is recommended that the weighing vessel is installed somewhere where the pressurization is constant. It is advisable to calibrate the load cells to match the pressurized floor’s constant pressure level. This will avoid unwanted side loads on the load cells, which can impair the accuracy of the weighing process.
As you can see, there are several aspects to weighing that can have a dramatic effect on the quality of the finished product. Inaccuracies in the weighing process can affect the consistency of a blend of ingredients and the correct potency of the final product. A consistent weighing process can reduce these risks and ensure high-quality products. Therefore, it is crucial to consider all aspects of weighing when designing a process according to QbD principles.
The weighing system is susceptible to electrical noise. This can be due to lightning, radio transmitters, or other sources of electrical noise. An isolated NEMA-rated junction box and a strain-gauge area can prevent the effects of such noise. To minimize these effects, it is essential to use a hermetically sealed strain-gauge area. Cable entry points should be welded closed. Further, if the weighing system has a high-quality load cell, it will eliminate any problems associated with electrical noise.