초록 ▼

The optical reflectance or transmittance concentration analyzer includes an acousto-optical tunable filter (AOTF). The AOTF is tuned by a computer controlled digital-to-analog converter through a tunable sweep oscillator. Tuned beams can be selected according to their direction of propagation or acc

The optical reflectance or transmittance concentration analyzer includes an acousto-optical tunable filter (AOTF). The AOTF is tuned by a computer controlled digital-to-analog converter through a tunable sweep oscillator. Tuned beams can be selected according to their direction of propagation or according to their polarization behavior. Therefore, if desired, a pair of crossed polarizers can be used to select one of the tuned monochomatic light beams that pass from a light source through the AOTF. To obtain rapid wavelength change along with electronic chopping or wavelength modulation, the digital-to-analog converter output is combined with the output of a high speed signal generator. The modulated light is conducted directly or through a fiber optic cable to the location of the optical measurement and impinges upon the sample where it is reflected or transmitted. The emerging light is collected onto detector(s). The measurement time interval can be distributed among the required wavelengths or wavelength pairs according to an unequal scheme to decrease the error of the result in a calibration equation. The apparatus is particularly adaptable for use as an on-line concentration monitor in industrial process control because of its stability, efficiency and ability to perform quick analyses.

대표청구항 ▼

An apparatus for providing rapid random wavelength access for optical analysis of a sample comprising, (a) a light source, (b) an acousto-optic tunable filter positioned to accept light from the light source and provide emerging tuned output beams, (c) means to select a predetermined number of tuned

An apparatus for providing rapid random wavelength access for optical analysis of a sample comprising, (a) a light source, (b) an acousto-optic tunable filter positioned to accept light from the light source and provide emerging tuned output beams, (c) means to select a predetermined number of tuned beams from the acousto-optic tunable filter, (d) means to direct said predetermined number of selected tuned output beams onto the sample to be analyzed, (e) means to collect radiation that is reflected back to transmitted through said sample, (f) means for detecting and amplifying the reflected or transmitted radiation, (g) electronic tunable oscillator means connected to said acousto-optic tunable filter, (h) electronic means providing timing and logic for wavelength selection via said electronic tunable oscillator means, and (i) means for generating a predetermined periodic signal, said electronic means providing timing and logic for wavelength selection including means for generating a non-periodic signal, means for combining the periodic signal with the non periodic signal to provide a control input signal to the electronic tunable oscillator means to permit optical analyses of at least two discrete optical qualities of said sample.