A method for controlling the direction of which - and forth movement of a movable mirror of an interferometric spectrophotometer.

摘要

A method and apparatus for controlling the reciprocation of a movable mirror of an interferometer used in an interferometric spectrophotometer are disclosed, wherein a frequency dividing ratio corresponding to a desired reciprocating speed of the movable mirror is set and then a pulse signal from an oscillator is divided at the frequency dividing ratio for producing a frequency-divided signal which in turn is compared with an interference signal from a control interferometer to produce an error signal for controlling the reciprocating speed of the movable mirror based on this error signal until the desired reciprocating speed is reached. Preferably, the frequency dividing ratio can be varied by a central processing unit, for example, so that the user is able to freely change the reciprocating speed of the movable mirror to conform to the type of a detector used, thereby enabling a measurement under optimum conditions. IMAGE