skip to main content
DOE Patents title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Calibration-free optical chemical sensors

Abstract

An apparatus and method for taking absorbance-based chemical measurements are described. In a specific embodiment, an indicator-based pCO2 (partial pressure of CO2) sensor displays sensor-to-sensor reproducibility and measurement stability. These qualities are achieved by: 1) renewing the sensing solution, 2) allowing the sensing solution to reach equilibrium with the analyte, and 3) calculating the response from a ratio of the indicator solution absorbances which are determined relative to a blank solution. Careful solution preparation, wavelength calibration, and stray light rejection also contribute to this calibration-free system. Three pCO2 sensors were calibrated and each had response curves which were essentially identical within the uncertainty of the calibration. Long-term laboratory and field studies showed the response had no drift over extended periods (months). The theoretical response, determined from thermodynamic characterization of the indicator solution, also predicted the observed calibration-free performance.

Inventors:
Issue Date:
Research Org.:
Univ. of Montana, Missoula, MT (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1175700
Patent Number(s):
7026165
Application Number:
09/775,386
Assignee:
University Of Montana
Patent Classifications (CPCs):
G - PHYSICS G01 - MEASURING G01N - INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
Y - NEW / CROSS SECTIONAL TECHNOLOGIES Y10 - TECHNICAL SUBJECTS COVERED BY FORMER USPC Y10T - TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
DOE Contract Number:  
FG03-94ER6224
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
47 OTHER INSTRUMENTATION

Citation Formats

DeGrandpre, Michael D. Calibration-free optical chemical sensors. United States: N. p., 2006. Web.
DeGrandpre, Michael D. Calibration-free optical chemical sensors. United States.
DeGrandpre, Michael D. Tue . "Calibration-free optical chemical sensors". United States. https://www.osti.gov/servlets/purl/1175700.
@article{osti_1175700,
title = {Calibration-free optical chemical sensors},
author = {DeGrandpre, Michael D.},
abstractNote = {An apparatus and method for taking absorbance-based chemical measurements are described. In a specific embodiment, an indicator-based pCO2 (partial pressure of CO2) sensor displays sensor-to-sensor reproducibility and measurement stability. These qualities are achieved by: 1) renewing the sensing solution, 2) allowing the sensing solution to reach equilibrium with the analyte, and 3) calculating the response from a ratio of the indicator solution absorbances which are determined relative to a blank solution. Careful solution preparation, wavelength calibration, and stray light rejection also contribute to this calibration-free system. Three pCO2 sensors were calibrated and each had response curves which were essentially identical within the uncertainty of the calibration. Long-term laboratory and field studies showed the response had no drift over extended periods (months). The theoretical response, determined from thermodynamic characterization of the indicator solution, also predicted the observed calibration-free performance.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2006},
month = {4}
}

Patent:

Save / Share:

Works referenced in this record:

Porous plastic optical fiber sensor for ammonia measurement
journal, January 1989


Simultaneous mooring-based measurements of seawater CO2 and O2 off Cape Hatteras, North Carolina
journal, January 1997


Fiber-optic sensors based on reagent delivery with controlled-release polymers
journal, January 1989


Development of a fiber optic sensor for measurement of pCO2 in sea water: design criteria and sea trials
journal, June 1992


Fiber-optic fluorosensor for oxygen and carbon dioxide
journal, October 1988


Enzyme-based fiber optic zinc biosensor
journal, March 1993


A Fiber Optic Chemical Sensor For Carbon Dioxide Dissolved In Sea Water
conference, February 1990


An Autonomous Sensor and Telemetry System for Low-Level pCO 2 Measurements in Seawater
journal, January 1999


Chemically and mechanically resistant carbon dioxide optrode based on a covalently immobilized pH indicator
journal, October 1993


Fiber optical fluorosensor for determination of halothane and or oxygen
journal, November 1985


Spectrophotometric seawater pH measurements: total hydrogen ion concentration scale calibration of m-cresol purple and at-sea results
journal, October 1993


Multiple-indicator fiber-optic sensor for high-resolution pCO2 sea water measurements
journal, March 1993


In situ measurements of seawater pCO2
journal, July 1995


Fiber-optic oxygen microsensors, a new tool in aquatic biology
journal, September 1995


Absorption-based sensors
journal, October 1995


A new optical sensor for PCO2 measurements in seawater
journal, June 1993


Solenoid Pumps for Flow Injection Analysis
journal, January 1996


Measurement of sodium hydroxide concentration with a renewable reagent-based fiber-optic sensor
journal, October 1990


Tailoring of Sol−Gel Films for Optical Sensing of Oxygen in Gas and Aqueous Phase
journal, January 1998


High precision multiwavelength pH determinations in seawater using cresol red
journal, May 1989


Fiber optic pH probe for physiological use
journal, May 1980


Calibration-Free Optical Chemical Sensors
journal, March 1999