Method for the determination of points on a specimen carrying a specific signal frequency by use of a scanning microscope

摘要

A method and apparatus for determination of specific points on a specimen carrying a signal having a specific signal frequency by use of a scanning microscope. A detector provides a secondary electrical signal corresponding to respective particular scan points. An output of the detector connects to first and second evaluation circuits which each output a signal based on and representative of the specific signal frequency. The first evaluation circuit has a band-width substantially narrower than the second evaluation circuit. An output signal of the second evaluation circuit determines when to switch a scanning generator of the scanning microscope from a first scan rate to a second slower scan rate. The output signal of the first evaluation circuit is employed for evaluation relative to the specific points carrying the specific signal frequency.