Abstract: Time-divisionally-multiplexed light receiving signals are sampled at a predetermined time interval as they are, and then converted into digital data. Then, address is determined based on an index signal as a standard of the time-divisional multiplexing, and the data are sequentially stored in a data memory. When the data are sequentially read out, change of quantity of the data is obtained to determine a period having the smallest change in quantity as an effective period. Then, the data included in the effective period are selected and separated to a sample side beam, reference side beam and cutoff period. Thus, the multiplexed light receiving signals are accurately separated by the digital data.

Abstract: In a detector for spectrometry attached to an integrating sphere, a plurality of detection elements having different spectral sensitivity characteristics is arranged side by side in the same plane on a base, and a side cover is provided such that the detection elements receive light. Thus, the measurement light is directly irradiated to the respective detection elements. Accordingly, the detector for spectrometry has a fast response speed and is excellent in the sensitivity characteristics in a wide wavelength region in the near-infrared area.

Abstract: In a spectrophotometer, light emitted from a light source is processed to provide monochromatic light by a monochromator, and reaches a sector mirror having a chopper function. The sector mirror is rotated by a motor, and a rotational frequency of the motor can be controlled by a controller. By rotation of the sector mirror, monochromatic light is alternately distributed to a sample cell and a reference cell through a mirror. In measuring a wavelength range where a detector having a photomultiplier with a fast response speed is used, the motor is rotated at a high speed, so that time for scanning a wavelength is shortened. In measuring a wavelength range where a detector having lead sulfide with a slow response speed is used, the motor is rotated at a low speed to obtain a sufficiently strong signal intensity. Accordingly, in the spectrophotometer, the analysis time can be shortened, and the sufficiently strong signal can be outputted at the same time.

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.