A triple beam balance is used to measure the mass of objects. The machine is very precise and has a reading error of +/- 0.05 grams.
The machine gets its name due to its three beams, which all carry weights. The front beam reads continuously up to 10 grams, and the middle beam always reads in 100-gram increments. The far beam is responsible for measuring in 10-gram increments, and each weight must be placed in its appropriate groove.
It is important when using a triple beam balance to always take two readings for the most accurate weight possible. If using a container to hold the material to be measured, measure the container first, and then add the material.