Abstract: A spectrophotometer which takes out monochromatic lights from lights from light sources by using spectroscopes and transmits the monochromatic lights through a sample and detects the transmitted lights by sensors includes a plurality of dispersing elements in the spectroscope which bear the dispersion of different wavelength ranges or a plurality of sensors which bear the detection of different wavelength ranges in order to widen a measurement wavelength range; and means for correcting the difference between measured values obtained when the different dispersing elements were used or the difference between measured values obtained when the different sensors were used at one wavelength in overlap wavelength regions between different wavelength ranges so as to be set to zero.

Abstract: The invention relates to a spectrophotometer having a light source capable of alternatively producing near infrared radiation and another radiation other than the near infrared radiation, a dispersing section for dispersing radiation from the light source to provide substantially monochromatic radiation so that a sample is irradiated with the substantially monochromatic radiation to thereby provide sample radiation, and a sensing section for sensing the sample radiation. The sample radiation is subjected to energy absorption of a specific wavelength by the sample. The sensing section includes a first sensing unit having a near infrared radiation sensor, a second sensing unit having a visible/ultraviolet radiation sensor and a temperature control unit for holding the near infrared radiation sensor at a substantially constant temperature lower than the room temperature.

Abstract: A spectrophotometer having functions of both of a double-monochromator and a single-monochromator including a light source, a first spectroscope having a first slit through which light from the light source passes and a first dispersion element for dispersing the light from the first slit, a second spectroscope having a second slit for receiving light dispersed from the first dispersion element for dispersing the light from the second slit, and a third slit for receiving the light dispersed from the second dispersion element. A sample compartment is provided for transmitting the light from the first dispersion element or from the third slit directly to a detector or through a sample to the detector. An optical unit is provided for changing transmitting light paths between a first light path for transmitting the light from the first dispersion element to the sample compartment through a fourth slit and a second light path for transmitting the light from the third slit to the sample compartment.

Abstract: Light irradiated to a sample is detected by a detector in order to measure the optical properties of the sample. The image of a minute virtual light source for the light is focused in the neighborhood of the measuring face of the sample by a first optical system arranged between the light source and the sample. The light outgoing from the sample is incident to the detector by way of a second optical system arranged between the sample and the detector and having conjugate points in the neighborhood of the measuring face of the sample and of the light receiving point of the detector.

Abstract: A photoelastic effect measuring device comprising a single white light source, a prism dispersing light emitted by said white light source and a variable slit device, which selects an arbitrary spectrum of light thus dispersed is disclosed, in which for a photoelastic effect measurement using white light, the slit width is opened totally so that all the light spectrum pass therethrough so as to pass through a sample to be measured and for a photoelastic effect measurement using a specified monochromatic light beam, the slit width is controlled so as to have a predetermined opening so that only a specified light spectrum can pass therethrough so as to pass through a sample to be measured.