German Test Slide (PTB)
Technology
The following pictures show a German test chip made for the Physikalisch-Technische Bundesanstalt (PTB) (German Physical and Technical standardisation organisation).
This slide is designed for reflected light only and we have found it to be of excellent quality for testing our microscopes down to 100nm.
On the micrometer scale, the distance measured is that between the first two lines (1 micrometer = 1000nm)
