This paper describes 13 steps for safe, accurate weighing in safety cabinets or other enclosures. more
Recognize and detect the effects of electrostatic charges on your balance
Electrostatics test explains how you can recognize and detect the effects of electrostatic charges on your own balance and presents solutions on how you can ensure your results are free from the influences of electrostatic charges.
Even if your balance settles, you need to be sure electrostatic charges aren't influencing your results.
Did you know that your samples and containers can become electrostatically charged just through normal handling? The most common ways that charging occurs is through picking up and putting down containers, handling sample containers, movement of the sample inside the container, and in the actual dosing of the sample. The resulting net charge on the sample and/or its container sets up an electric field between the container and the balance. The forces due to the electric field act upon the weighing pan which the balance interprets as mass, and can cause substantial error in the indicated weight value (0.1 g on an analytical balance is not uncommon).
As the charge dissipates, the force decreases and the balance reading will change accordingly. This is observed as a drifting weight value and the balance does not stabilize. However, if the charge dissipates slowly, the balance may be able to stabilize. There is a high risk that there may be errors in your weighing results of which you are not aware.