When tracing point A is moved along curve a, the planimeter travels along axis x-x and gear 1, rigidly attached to guide roller d, turns pinion 2. Rotation is transmitted from pinion 2 by means of spherical segment b to roll 3. Roll 3 is rigidly attached to worm e which transmits rotation further to worm wheel 4 and recording wheel f. The rotation of roll 3, indicated by recording wheel f, is proportional to integral K which equals K=(ρ₁/(2πrρ₂))*∫(sin(γ))dx where ρ₁ and ρ₂ are the radii of segment b and roll 3.
$3440$CF,MO$