Optical spectrophotometer with wavelength modulation
US5231462A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 25, 1992 |
| Grant date | Jul 27, 1993 |
| Priority date | — |
| Expiry date | Feb 25, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2201/069
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A spectrophotometer useful for measuring absorption or emission bands of a substance irradiated with optical radiation, comprises a light source for producing the optical radiation, a monochromator for isolating light of wavelength (W) from the optical radiation and which modulates the wavelength (W) by a predetermined wavelength amplitude (.delta.W), and a photodetector for detecting the intensity of light passing through the monochromator and for producing a measuring signal in response thereto. The monochromator operates under the control of an electronic control unit which produces a control signal that causes the monochromator to scan across a portion of the spectrum of the optical radiation at a frequency (f.sub.2) to transmit a narrow band of radiation at the wavelength (W). The control unit includes a modulation generator which produces a signal that causes the monochromator to modulate the wavelength (W) by the predetermined wavelength amplitude (.delta.W) at a frequency (f.sub.1). The spectrophotometer also includes an electronic evaluation unit which amplifies an a.c. component of the measuring signal that is attributable to the wavelength modulation in synchronization w…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.