Patent · US Expired

Spectrophotometric method and spectrophotometer for performing the method

US5387979A · kind A · utility

11Cited by

2References

16Claims

0Family size

Assignee

Siemens Elema AB · SE

Inventors

Stefan Brauer · Waiblingen, DE
Rolf Castor · Stuvsta-Snättringe, SE
Anders Linge · Katrineholm, SE
Sven-Gunnar Olson · Arlöv, SE

Key dates

Filing date	Aug 19, 1993
Grant date	Feb 7, 1995
Priority date	—
Expiry date	Aug 19, 2013

Classification

Technology area (CPC G)Physics
CPC primaryG01N21/314
WIPO fieldMeasurement
WIPO sectorInstruments

Abstract

In a spectrophotometer for measuring the concentration of a specific substance, a pulsating (modulated) source of radiation gives rise to an alternating current component, a direct current component and a dark signal component in a measurement signal. The response time for changes in the concentration of the specific substance is reduced while the measurement signal's signal-to-noise ratio is simultaneously improved when the pulsation frequency is from 50 to 1000 Hz, and the direct current component in the measurement signal is filtered out for normalization by a reference signal in a signal analyzer so the concentration of the specific substance can be calculated.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.