Abstract: A zoom lens is provided between the sample and the slit of a spectrophotometer to change the size of the image of the sample on the slit plane. The picture of the sample is taken by the zoom lens and is shown on a display screen, on which a window is superimposed. When the operator changes the location of the window, the sample is moved accordingly, and when the operator changes the size of the window, the focal length of the zoom lens is changed, whereby the size of the measurement area is changed. By changing the size of the measurement area on the slit plane while the size of the elementary photo-sensors of a photo-detector is unchanged, the resolution of the two-dimensional spectrophotometry can be changed.

Abstract: A spectrophotometer for measuring a two-dimensional area or a spot area in a rather broad surface of a sample, where the spectrophotometer is provided with a camera for taking the picture of the sample surface. The picture is shown on a display screen, and the operator can move a window superimposed on the sample picture in the display screen by using a mouse or the like to a desired place on the sample surface. The sample stage on which the sample is mounted moves according to the movement of the mouse, whereby a spectrophotometric measurement of the desired place (two-dimensional area or the spot area) on the sample is facilitated.

Abstract: In a spectrophotometer according to the present invention, electric signal from a photo-detector is converted into digital data by an A/D convertor and stored in a memory. In the process of correcting data, a signal processing unit first reads out from the memory data of a wavelength of a plurality of points consisting of a target point to be corrected and other points in a predetermined proximity of the target point in the two-dimensional area on the sample surface. Then the signal processing unit corrects the data of the target point using the data of the other proximal points. In correcting data, a set of two weights a.sub.i and b.sub.j are assigned to every one of the points, where the values of the weights a.sub.i change according to the position of the points in the X direction and the values of the weights b.sub.j change according to the position of the points in the Y direction. By predetermining the values of the weights a.sub.i and b.sub.

Abstract: A near infrared analyzer has, arranged on a base, a halogen tungsten lamp as light source, an optical stop for light from the source, an optical system for converging a flux of light for measuring and directing it to a measuring section and a system including an integrating sphere at which a sample is set. A spectrometer part has its entrance slit placed on the bottom surface of the integrating sphere, and includes a diffraction grating for diffraction and dispersion of incident light flux from the entrance slit, an arrayed detector and a reflective mirror for reflecting the diffracted light from the diffraction grating so as to be dispersed and focused on the surface of the detector. Signals from the detector can be sequentially retrieved for electronically scanning wavelengths without mechanically oscillating or rotating the grating. This makes it possible to maintain high accuracy in wavelengths over a long period of time.