Roberval’s balance

Commonly used scale that operates on the same principle as the beam balance; the pans are stabilized by a shank and rest on the beam.

base

Support that provides stability to the scale.

pan

Flat rigid support that holds either the body to be weighed or the weights.

beam

Horizontal metal bar that balances on a vertical axis and supports a pan on each end.

weight

Piece of metal, such as copper or iron, of known mass that is placed on a pan to balance the scale and thereby assess the corresponding mass of a body.

pointer

Metal needle that indicates the point of equilibrium on the dial when the beam is level.

dial

Graduated surface with a pointer in front that indicates the point of equilibrium for the two pans.