On-site analyzer

• US 6,707,043 B2
• Filed: 07/22/2002
• Issued: 03/16/2004
• Est. Priority Date: 08/14/1998
• Status: Expired due to Term

• Current Assignee: Spectro Scientific, Inc.
• Original Assignee: On-Site Analysis, Inc. (Spectro Scientific, Inc.)
• Inventors: Coates, John, Rosenbaum, Neil, Abuneaj, Yosef
• Primary Examiner(s): Sugarman, Scott J.
• Assistant Examiner(s): HANIG, RICHARD E
• Application Number:
  US10/201,184
• Publication Number:
  US 20020185604A1
• Time in Patent Office: 603 Days
• Field of Search: 250/339.09, 250/338.1, 250/252.1, 356/313, 356/307, 702/8, 702/23, 702/24
• US Class Current: 250/339.09
• CPC Class Codes: G01J 3/28 Investigating the spectrum using colour filters G01J3/51
• CPC Class Codes: G01J 3/443 Emission spectrometry
• CPC Class Codes: G01N 21/274 Calibration, base line adjustment, drift correction
• CPC Class Codes: G01N 21/3577 for analysing liquids, e.g. polluted water
• CPC Class Codes: G01N 21/67 using electric arcs or discharges
• CPC Class Codes: G01N 21/69 specially adapted for fluids , e.g. molten metal
• CPC Class Codes: G01N 33/2847 Water in oils
• CPC Class Codes: G01N 33/2858 Metal particles
• CPC Class Codes: G01N 33/2888 Lubricating oil characteristics, e.g. deterioration lubricating properties G01N33/30
• CPC Class Codes: G01N 33/30 for lubricating properties

Abstract

An apparatus (10) for analyzing lubricant oils and functional fluids includes an optical emission spectrometer (OES) (26) having a substantially continuously valued wavelength versus intensity output (140). The OES (26) analyzes light captured from a spark emission stand (58) through which the fluid sample is flowed. An expert system (160-172) operates according to a set of Rules, and generates diagnostic text (174) for an operator based on the information about the fluid sample provided by the OES (26) and other measurement devices. The apparatus (10) is reduce in size, weight and cost.

Claims

1. A method of regularizing a sample spectrum of a fluid sample generated by a spectrometer having a pair of electrodes, the method comprising the steps of:

(A) defining a background spectrum having a plurality of spectral features indicative at least in part of the composition of the electrodes;

(B) selecting at least a first background spectral feature from said plurality of spectral features wherein the first background spectral feature has a predetermined wavelength value associated therewith;

(C) determining a measured wavelength value of the at least first background spectral feature in the sample spectrum; and

,

(D) translating the sample spectrum with respect to wavelength in accordance with said predetermined wavelength value, said measured wavelength value, and a predetermined translation strategy.

2. The method of claim 1 wherein the sample spectrum comprises an array of values representative of wavelengths and spectral intensities associated therewith over a spectral range, wherein said plurality of spectral features are defined by corresponding emission lines, and wherein step (B) is performed by the substep of:

selecting a plurality of emission lines from the background spectrum wherein each selected emission line has a respective predetermined wavelength value associated therewith.

3. The method of claim 2 wherein step (C) is performed by the substeps of:

identifying the plurality of selected background emission lines in the array of values; and

,

determining a respective measured wavelength value of the identified emission lines in the array.

4. The method of claim 3 wherein step (D) is performed by the substeps of:

determining a respective wavelength offset between the predetermined wavelength values and the measured wavelength values;

converting the wavelength offsets into a composite wavelength offset for the sample spectrum;

determining a pixel shift number as a function of the composite wavelength offset; and

,

shifting the spectral intensities of the array of values by the pixel shift number to thereby regularize the sample spectrum with respect to wavelength.

5. The method of claim 1 wherein the fluid sample comprises one of used lubricating oil and used functional fluid, and step (A) includes the substeps of:

exciting a new sample of said one of lubricating oil and functional fluid corresponding in type and grade to the used sample to spectroemissive levels to thereby generate radiation;

acquiring a background spectrum responsive to the radiation; and

,

storing the background spectrum for subsequent use.