توریهای منطقه ای فرنل و روزنه های دایروی با پایه نگهدارنده (Circular openings and Fresnel's Zone Plates with holder)
Model 221501
Optic Experiments Equipment
![](https://moolianco.com/wp-content/uploads/2019/08/توری-های-منطقه-ای-و-روزنه-و-موانع-دابروی-با-نگهدارنده-e1579684901396.jpg)
To investigate generation of convergent light beams with the assistance of Fresnel’s zone theory. The diaphragm has a system of 20 light a dark rings, limit circles between the rings have a diameter dn=۱.۵۹۱n½ (n=1 , 2 , …); focal distance for He-Ne light ( λ = ۶۳۲.۸ nm ) , f = 1 , 1.5 , 2 m – size = 50 × ۵۰ mm . The plates are odd and even. And there is a diaphragm with f = 14 mm approx. only for observation and education
Diameter of holder : 12 Cm
Stand rod : 13 Cm × ۸ mm