The relative humidity in the electronic balance weighing room should be maintained between 55% and 75%, ideally between 65% and 75%. Excessive humidity, above 80%, can lead to significant adsorption on the balance components, particularly agate parts, causing the balance to move slowly. It can also lead to corrosion of metal parts and the formation of mold spots on optical surfaces. Below 45% humidity, materials are prone to static electricity, which can result in inaccurate weighing. Generally, humidity within the instrument's applicable range has no significant impact, but it may have a more pronounced effect on your samples.
The balance will change according to its environment. Normally, the temperature should be maintained between 18-26°C, with fluctuations not exceeding 0.5°C/h. The main impact of temperature is that changes in temperature can cause thermal expansion and contraction. Low temperatures greatly affect the operator's body temperature and the heat from light sources, which can cause zero-point drift. Precision balances have many finely detailed components, and changes in temperature can affect and alter the gaps between them. This sensitive balance will record these changes, impacting the accuracy of the readings. The degree of influence temperature has on the balance mainly depends on the balance's small weighing fraction, such as balances with a fraction over 100,000.
During the weighing process, it is common for samples to continuously absorb moisture from the air, causing the weight value to drift. In such cases, it is recommended to weigh the samples in covered containers like weighing bottles. The weighing of the balance must be conducted in a stable, dry, and humidity-controlled environment. In high humidity conditions, the adhesive force on the surface of the balance components may change, and over time, it can lead to rusting of the components, significantly reducing the sensitivity of the balance. This results in inaccurate weighing.
