What is triple beam balance?

See below

Step-by-step explanation:

A triple beam balance is a balance with three beams with sliding weights to measure the weight of the object.

One beam has notches for a sliding weight in 100 g increments.

A second beam has notches for a sliding weight in 10 g increments.

The third scale has no notches. It reads from 0 to 10 g, with the smallest division being 0.1 g.