We offer flatness calibrations of optical flats along individual sections with scanning lengths of up to 900 mm by means of a small-angle deflectometer (deflectometric flatness reference – DFR) developed at PTB. Typical applications are in the optical industry or in the field of X-ray optics. The SUTs may weigh up to 150 kg, and their slope may not exceed 100 arcsec. In the case of non-reflective surfaces, it must be ensured that the reflection of the rear side does not run in the same direction as the reflection of the front side. If need be, the individual sections can also be merged to form a global topography. The expanded measurement uncertainties (k = 2) are in the nanometer range and depend, among other things, on the scanning length. The lateral resolution is in the range of a few millimeters.
Figure: Small-angle deflectometer for flatness measurements
Contact
Dr.-Ing. Gerd Ehret
Phone: +49 531 592-4220
E-Mail: gerd.ehret(at)ptb.de