Abstract
When we calculate the wind velocity from the pressure difference in wind tunnel, it is very complex to calculate by slide rule or calculator; then, on the occasion when we give official approval to Robinson's cup anemometer by wind tunnel, the calculation is very hardfull for the routine use.
So I try to calculate the velocity easily by nomograph. The nomograph is a collinear one that has four variables and these variables are wind velocity, height of alcohol in manometer, specific gravity of alcohol and air density.
