Pyramidal Balance

Pyramidal Balance can be divided into two main groups: internal and external. The group names are derived from their location relative to the test model and wind tunnel test section internal balances reside inside a test model, while external balances reside outside the test section. During the early years of wind tunnel testing, Forces and Moments were literally measured through pan-type balances. Although technology has advanced dramatically since those early days, the term balance is still applied to the devices used for Force and Moment measurements today.

Small Pyramidal Balance
Minimum required height below test section approximately 13 inches
Approximate resolving center height 12 inches
Large Pyramidal Balance
Minimum required height below test section approximately 40 inches 
Approximate resolving center height 40 inches
Medium Pyramidal Balance
Minimum required height below test section approximately 46 inches
Approximate resolving center height 16 inches.