Measuring flatness normally using optical flats .Optical flats are optical-grade glass structures lapped and polished to be extremely flat on one or both sides, usually within a few millionths of an inch. Holding the surface of a high precision optical flat against the test specimen under monochromatic light creates visible light bands, which are formed by the air gaps where the two surfaces are not in perfect contact. These interference fringes show the contour of the surface under test. The light and dark patterns visually represent the flatness of the surface being tested, and it is the curve and spacing between these fringes which indicate the surface accuracy. The spacing between the fringes decreases where the gap is larger, indicating a departure from flatness in one of the two surfaces.

Specification:

Size(mm)	A	B	C	D	E	F	G	H
OD	30	45	60	80	100	150	200	250
Thickness	15	15	20	20	25	30	40	45

Patterns of light bands >

> Mechanical seals> Spring Energised Seals
> Related Products
• Products
• Services
• Enquiry
• About Us
• Contact Us
• News