Weighing is a crucial part of every industrial manufacturing process. From weighing raw materials entering your warehouse to analyzing ingredients for quality compliance, you need precision and reliability in the weighing process.
It’s important to understand how a chemical substance should be transferred from a weighing receiver to the container that will hold it. This is the only way to ensure that a true and accurate weight has been achieved.
Weighing Procedures
Precise weighing ensures that ingredients are added in the correct order and proportion, helping to maintain product quality. This helps businesses reduce raw material waste and saves on operating costs. In addition, fewer mistakes and waste means higher profitability.
A good weighing process is dependent on a number of factors. For example, analytical balances are high-precision instruments that must be carefully operated. They require a draft-free location on a solid bench that is free of vibrations. They also need to be calibrated regularly with a standard weight to maintain accuracy.
Similarly, when weighing powders, care must be taken not to touch them. It’s best to use gloves and tongs when handling them. Alternatively, they can be stored in a container and then placed on the balance with the weighing paper. After zeroing the balance, the sample can be inserted and then the reading recorded. It’s important to let the balance stabilize before recording a reading.
Analytical Balances
For tasks that require the highest levels of precision, analytical balances are an essential piece of equipment. Available in a variety of shapes and sizes, these high-performance instruments provide advanced functions that assist with formulation, density determination, purity analysis and quality control testing.
These devices feature a glass draft shield to guard against air currents that can negatively affect readings. They also often include a ‘Mode’ button to configure the system, level adjustment feet, an ‘On/Off’ switch and a display panel.
To use an analytical balance, find a quiet space where the device can be placed on a flat and stable surface. Once it’s powered on and connected, wait for the internal checks to complete before displaying zero weight. Then, open the weighing pan door and carefully place your substance into the center of the weighing platform using tongs or tweezers (fingerprints can add mass). Once complete, close the glass draft shield and allow the reading to stabilise.
Transfer of Samples to Receiving Containers
When you’ve precisely weighed out a sample, you want to be able to move it to the destination container without losing any mass. That’s why most labs prefer weighing boats, glassine paper and other purpose-made weighing containers. They are designed to minimize material sticking. If they do, however, you can dislodge solids by tapping lightly or scraping with a transfer tool while pouring.
A good tip is to keep a second clean container ready to receive the transferred specimens. That way, you can start a new chain of custody immediately after completing the previous one.
Titian’s Mosaic software features seamless liquid handler integration to help with this process. It can also automatically calculate the required volume of water, solubilise and transfer the sample(s) and perform a check-weigh to complete the process. This avoids delays in resolving transfer problems and provides an audit trail of all actions performed on the instrument. This enables you to comply with 21 CFR Part 11 regulations for full traceability.
Weighing Paper
Weighing paper is a smooth, abrasion-resistant and moisture-resistant sheet of paper that prevents samples from gunking up the weight balance pan. This keeps the measurement process simpler, faster and more professional.
Grade B-2 Whatman weighing papers are moisture-resistant and dissolve residue-free in acid solutions for Kjeldahl nitrogen analysis. They come in a convenient dispenser box and include instructions for use.
The tare button on your balance removes the weight of the weighing paper or weighing boat from the measured result, ensuring that you are only measuring the sample. This is especially important if you plan to reuse the weighing paper or weighing boat for another weighing. You should also tare your weighing boat or paper when you are done, as this is a good way to keep your balance clean and accurate. However, do not rinse the weighing paper or weighing boat for standard preparation unless it is specifically permitted to do so. Rinsing the weighing paper could introduce solvents that could contaminate your standard.