Which tool should be used to handle metric weights on a Class A balance?

Handling metric weights on a Class A balance requires precision and care to ensure that the weights remain uncontaminated and to maintain their integrity. Using forceps is the ideal choice for this task, as they allow the user to securely grip and manipulate the weights without adding oils or contaminants from their fingers. The precision offered by forceps ensures that the weights are handled safely, minimizing the risk of damaging sensitive equipment or compromising the accuracy of measurements.

Other options do not provide the same level of effectiveness for this specific handling requirement. Gloves can create a barrier against contamination but may not provide the precision needed to securely handle small weights. Pins might be unsuitable as they could scratch or damage delicate weights. Applicators are generally used for applying substances rather than for handling weights, which makes them less appropriate for this particular function. Therefore, forceps are the correct tool for handling metric weights on a Class A balance.