Tips and Tricks for Proper Weighing

METTLER TOLEDO has launched an email series of additional tips and tricks to help researchers and scientists to improve weighing performance in laboratories. Register at

Online PR News – 18-May-2012 – Greifensee, Zurich – Balances are among the most commonly used instruments in any laboratory. From sample weighing and check weighing to weighing miniscule amounts up to kilograms, weighing results always greatly depend on the performance of the balance. Are you sure that your balance works correctly? There are regular balance checkups that enable functioning and accurate balances; but did you know that your handling also has a great influence on weighing performance?

Proper weighing technique directly affects the success and repeatability of your experiments. Below are a few simple things to remember that will greatly improve your weighing performance.

• Avoid electrostatic charges: Weighing vessels and samples may become electrostatically charged, particularly in dry air. Metal is the best material for weighing vessels, and glass is preferable to plastic as it is less susceptible to electrostatic charge. Reduce weighing errors by increasing atmospheric moisture and using anti-static kits.

• Avoid vibrations and drafts: Ideally, the balance room should be situated in the most vibration-free area of the building, and accessed through a sliding door. Locate the balance away from doors and areas of high traffic to avoid drafts. Do not weigh near windows or near radiators, which can cause strong air currents that may interfere with the balance. Avoid placing the balance in the air flow of air conditioning units or devices with fans, such as computers.

• Effects of Absorption/evaporation: Hygroscopic samples gain weight when they absorb atmospheric moisture while volatile samples evaporate and show a weight loss. Use clean, dry, stoppered weighing vessels with narrow necks. Keep samples in closed containers at all times.

• Reduce the influence of body heat: Heat radiating from an operator's body may have an adverse effect on weighing measurements. Where possible, avoid using the hands to place the weighing vessel in the weighing chamber, as this can alter temperature and atmospheric humidity. Wear a lab coat to reduce the effect of the body's surface temperature.

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