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US 5,418,614 AGranted
Optical photometry system for on-line analysis of fluid systems
AssigneeTexaco Inc.
InventorsDale F. Brost, Frank M. Rexach, Gregory A. Winslow
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Abstract
The present invention concerns a new optical photometry system for on-line analysis of industrial fluid streams. The invention is a general purpose optical photometer, capable of absorption, fluorescence and reflectance measurements at single wavelengths in the ultraviolet, visible and near infrared spectral ranges. Light signals generated by the light source are carried between a central photometric console and remote analysis sites by fiber optic cables. The return light signals are compared with a standard to make the desired analysis.
Claims12
An optical system for analysis of a fluid sample comprising:
- at least an analysis light source and a reference light source;
- means controlling said light sources to emit light pulses in sequence;
- probe means adapted to be positioned in close proximity to the fluid sample to be analyzed;
- first and second photodetector means, said second photodetector means having a first portion response only to said analysis light source and a second portion responsive only to said reference light source;
- means coupling output from said analysis light source to said probe means via a first analytical path, coupling light collected by said probe means to said first photodetector means via said first analytical path, coupling output from the reference light source to both said first and second photodetector means via respective first and second reference paths and coupling output from the analysis light source to said second photodetector means via a second analytical path;
- and
- means to integrate output from said first and second photodetector means to compare the sensed light from said probe means and reference light to analyze the sample wherein the start of the integration period is enabled when the output of said second photodetector means exceeds a constant threshold level.
4 more elements
A method for performing analysis of a fluid sample with an optical photometry system comprising the steps of:
- triggering an analysis light source to emit a brief analysis light pulse;
- filtering a first portion of said analysis light pulse to a wavelength appropriate for the analysis;
- transmitting said filtered analysis light pulse to a probe means directed at the fluid sample to be analyzed;
- collecting residual light transmitted through or emanating from said sample by said probe and transmitting said residual light to a first photodetector means;
- generating a first time varying electronic signal from the action of said residual light on said first photodetector means;
- transmitting a second portion of said analysis light pulse to a second photodetector means;
- generating a second time varying electronic signal from the action of said second portion of said analysis light pulse on said second photodetector means;
- generating a first and second integrated signal by simultaneously integrating said first and second time varying electronic signals with a dual-channel integrator, wherein the start of the integration period is enabled when the output of said second photodetector means equals a constant threshold level;
- storing said first and second integrated signals in separate sample-and-hold circuits;
- generating a first and second stored numerical value by digitizing said first and second integrated signals and storing said digitized signals in digital memory;
- triggering a reference light source to emit a brief reference light pulse;
- transmitting a first portion of said reference light pulse to said first photodetector means and transmitting a second portion of said reference light pulse to said second photodetector means;
- generating a third time varying electronic signal from the action of said first portion of said reference light pulse on said first photodetector means and generating a fourth time varying electronic signal from the action of said second portion of said reference light pulse on said second photodetector means;
- generating a third and fourth integrated signal by simultaneously integrating said third and fourth time varying electronic signals with a dual-channel integrator, wherein the start of the integration period is enabled when the output of said second photodetector means equals a constant threshold level;
- storing said third and fourth integrated signals in separate sample-and-hold circuits;
- generating a third and fourth stored numerical value by digitizing said third and fourth integrated signals and storing said digitized signals in digital memory;
- and
- comparing said first, second, third and fourth stored numerical values whereby the analysis of said sample can be determined.
15 more elements
Dependencies are inferred from the claim text.