steelyard balance
scale having a fixed fulcrum and a movable counterweight whose distance along a horizontal graduated beam is moved to balance a suspended object
en-US/ˈstilˌjɑɹd ˈbæləns/
en-GB/ˈstiːljɑːd ˈbæləns/
scale having a fixed fulcrum and a movable counterweight whose distance along a horizontal graduated beam is moved to balance a suspended object