ALEX BARTEL / SCIENCE PHOTO LIBRARY ALEX BARTEL / SCIENCE PHOTO LIBRARY
Lever balance. When a mass is placed on the pan, it exerts a downward force (weight). This force is transmitted via the system of levers to the counterweighted pointer. The size of the force determines how far the pointer is raised and the mass of the object (in grammes) is read off the scale.
Model release not required. Property release not required.