Method of spectral measurement

Claim 2

Method of spectral measurement according to claim 1, further comprising for wavelength calibration the steps of: determining a first address in correspondence with the theoretical position of an element of said linear photosensor array for which a maximum photoelectric output for each line spectrum is expected according to linear dispersion; determining a second address of an element at which the photoelectric output is maximum among elements around the first address; integrating the photoelectric outputs to obtain a first integrated value for a line spectrum of elements of said linear photosensor array with use of weight factors in relation to addresses of the element of the second address and of neighboring elements thereof included at least in a range double the mechanical width of the entrance slit; integrating the photoelectric outputs to obtain a second integrated value for a line spectrum of elements of said linear photosensor array with use of weight factors of one in relation to addresses of the element of the second address and of neighboring elements thereof included at least in a range double the mechanical width of the entrance slit; determining a third address in correspondence with the center-of-gravity wavelength of said linear photosensor array for each line spectrum by dividing the first integrated value by the second integrated value; and determining the center-of-gravity wavelengths of each element of said linear photosensor array according to wavelengths of said plurality of line spectra for calibration and the third addresses of said photosensor array in correspondence with the line spectra, whereby the calibrated center-of-gravity wavelengths are used in the processing of measured spectral data .

Claim 3

Method of spectral measurement, wherein the spectra of object light is measured and the convolution integral of the obtained data and a spectral effect curve is performed to obtain the effect amount, comprising the step of: interpolating the measured spectral data to obtain spectral data at wavelengths at which the measured half-bandwidth corresponds to the measured wavelength sampling intervals if the measured wavelength half-bandwidth is different from the measured wavelength sampling intervals, and performing the convolution integration of the obtained data and a spectral effective curve to obtain the effect amount.

Claim 4

A spectroradiometer, comprising: entrance means, including an entrance slit, for introducing light received from an object or from a light source of line spectra for calibration which radiates a plurality of line spectra at specified wavelengths; dispersion means for dispersing spectrally the light introduced by said entrance means; a linear photosensor array for converting the light dispersed by said dispersion means into an electric signal; first address-determining means for determining a first address in correspondence with the theoretical position of an element of said linear photosensor array for which a maximum photoelectric output for each line spectrum is expected according to linear dispersion determined by said dispersion means; second address-determining means for determining a second address of an element at which the photoelectric output is maximum among elements around the first address determined by said first address-determining means; and calculating means for calculating center-of-gravity wavelengths at each address with height factors including addresses of the elements.

Claim 5

A spectroradiometer according to claim 4, wherein said calculating means comprises: first integration means for integrating the photoelectric outputs for a line spectrum of elements of said linear photosensor array with use of weight factors in relation to addresses of the element of the second address and of neighboring elements thereof included at least in a range double the mechanical width of the entrance slit; second integration means for integrating the photoelectric outputs of a line spectrum of elements of said linear photosensor array with use of weight factors of one in relation to addresses of the element of the second address and of neighboring elements thereof included at least in a range double the mechanical width of the entrance slit; third address-determining means for determining a third address in correspondence with the center-of-gravity wavelength of said linear photosensor array for each line spectrum by dividing the integrated value of said first integration means for the line spectrum by the integrated value of said second integration means for the line spectrum; and means for determining the center-of-gravity wavelengths of each element of said linear photosensor array according to wavelengths of said plurality of line spectra for calibration and the third addresses of said photosensor array in correspondence with the line spectra.

Claim 6

A spectroradiometer according to claim 4, wherein the wavelength width of said entrance slit is set to be equal to the wavelength intervals of elements of said linear photosensor array.

Claim 7

A spectroradiometer according to claim 4, wherein said dispersion means includes a concave diffraction grating.

Claim 8

A spectroradiometer according to claim 4, wherein said entrance slit for said dispersion means is provided on the Rowland circle of said concave diffraction grating.