nisam siguran kako se meri ali ovo ce mozda da pomogne :
http://www.boatingmag.com/maintenance/understanding-propeller-pitchPitch is defined as "the distance a propeller would move in one revolution if it were moving through a soft solid, like a screw through wood." For example, a 21-pitch propeller would move forward 21 inches in one revolution.
nadam se da je jasno sta je pitch ili ugao
evo i slika :

po meni izmeris od ivice pera elise do vertikale sa vrha druge ivice pera (donji deo na osovini ) recimo da je to
X, pa onda visinu pera recimo da je to
Y ... i onda vidis koliko ima tih duzina
X u punoj evoluciji i pomnozis dobijenu vrednost sa Y i to ti je pitch
e sad mali trik , pitch je u incima a ne u centimetrima ....