Colorimeter optical measurement interference mitigation

Patent metadata

Field	Value
Publication number	US-12366522-B2
Application number	US-202318344436-A
Country	US
Kind code	B2
Filing date	Jun 29, 2023
Priority date	Jul 7, 2022
Publication date	Jul 22, 2025
Grant date	Jul 22, 2025

Abstract

An embodiment provides a method for measuring an analyte of a sample using a colorimeter, including: introducing the sample into a measurement chamber of the colorimeter, wherein the measurement chamber comprises an optical path from a light source to an optical sensor; identifying and waiting a sample settling period, wherein the sample settling period comprises a dynamic length of time, wherein the identifying comprises: measuring, using the optical sensor, a light throughput of the sample; and determining, based upon the measuring, the light throughput has reached a stable baseline; and obtaining a reference measurement of the sample when the stable baseline is reached. Other aspects are described and claimed.

First claim

What is claimed is:

1. A method for measuring an analyte of a sample using a colorimeter, comprising:
introducing the sample into a measurement chamber of the colorimeter, wherein the measurement chamber comprises an optical path from a light source to an optical sensor;
identifying and waiting a sample settling period, wherein the sample settling period comprises a dynamic length of time, wherein the identifying comprises:
measuring, using the optical sensor, a light throughput of the sample; and
determining, based upon the measuring, the light throughput has reached a stable baseline;
averaging a portion of measured light throughput and calculating a noise level;
performing a reference noise test by adding a fixed time to a cycle until reaching the stable baseline; and

obtaining a reference measurement of the sample when the stable baseline is reached.

2. The method of claim 1 , wherein the identifying comprises calculating a slope of the measured light throughput over time.

3. The method of claim 1 , wherein the identifying comprises performing a reference noise test by adding a variable time to a cycle until reaching the stable baseline.

4. The method of claim 1 , wherein the sample settling period comprises a continuous noise test until reaching the stable baseline.

5. The method of claim 1 , wherein the sample settling period comprises a continuous noise test until reaching the stable baseline and using a portion of the continuous noise test data as the reference measurement.

6. The method of claim 1 , further comprising performing another continuous noise test until reaching another stable baseline after a colorimetric indicator is added to the sample and using a portion of the another continuous noise test data as a sample measurement.

7. The method of claim 1 , wherein the waiting allows changing turbidity in the sample to stabilize in the optical path.

8. The method of claim 1 , wherein the waiting allows a meniscus of the sample to stabilize.

9. A measurement device for measuring an analyte of a sample using a colorimeter, comprising:
a measurement chamber;
a light source;
an optical detector;
a processor; and
a memory device that stores instructions executable by the processor to:
introduce the sample into the measurement chamber of the colorimeter, wherein the measurement chamber comprises an optical path from the light source to the optical sensor;
identify and wait a sample settling period, wherein the sample settling period comprises a dynamic length of time, wherein the identifying comprises:
measuring, using the optical sensor, a light throughput of the sample; and
determining, based upon the measuring, the light throughput has reached a stable baseline;
averaging a portion of measured light throughput and calculating a noise level;
performing a reference noise test by adding a fixed time to a cycle until reaching the stable baseline; and

obtain a reference measurement of the sample when the stable baseline is reached.

10. The device of claim 9 , wherein the identifying comprises calculating a slope of the measured light throughput over time.

11. The device of claim 9 , wherein the identifying comprises performing a reference noise test by adding a variable time to a cycle until reaching the stable baseline.

12. The device of claim 9 , wherein the sample settling period comprises a continuous noise test until reaching the stable baseline.

13. The device of claim 9 , wherein the sample settling period comprises a continuous noise test until reaching the stable baseline and using a portion of the continuous noise test data as the reference measurement.

14. The device of claim 9 , further comprising performing another continuous noise test until reaching another stable baseline after a colorimetric indicator is added to the sample and using a portion of the another continuous noise test data as a sample measurement.

15. The device of claim 9 , wherein the waiting allows changing turbidity in the sample to stabilize in the optical path.

16. A product for measuring an analyte of a sample using a colorimeter, comprising:
a non-transitory storage device having code stored therewith, the code being executable by the processor and comprising:
code that introduces the sample into a measurement chamber of the colorimeter, wherein the measurement chamber comprises an optical path from a light source to an optical sensor;
code that identifies and waits a sample settling period, wherein the sample settling period comprises a dynamic length of time, wherein the identifying comprises:
measuring, using the optical sensor, a light throughput of the sample; and
determining, based upon the measuring, the light throughput has reached a stable baseline;
averaging a portion of measured light throughput and calculating a noise level;
performing a reference noise test by adding a fixed time to a cycle until reaching the stable baseline; and

code that obtains a reference measurement of the sample when the stable baseline is reached.

Assignees

• Hach Co

Inventors

• Gorham Russell Paul
• Dervaes Nelson E

Classifications

• G01N2201/12

  Circuits of general importance; Signal processing · CPC title

• G01N15/075

  by optical means · CPC title

• G01N21/251 Primary

  Colorimeters; Construction thereof · CPC title

• G01N21/274

  Calibration, base line adjustment, drift correction · CPC title

• G01N2201/1248

  Validating from signal shape, slope, peak · CPC title