INLINE CONCENTRATION METER AND CONCENTRATION DETECTION METHOD

• US 20160169800A1
• Filed: 07/18/2014
• Published: 06/16/2016
• Est. Priority Date: 07/31/2013
• Status: Active Grant

• Current Assignee: Fujikin Incorporated, Tokushima University
• Original Assignee: Fujikin Incorporated, Tokushima University
• Inventors: Deguchi, Yoshihiro, Nagase, Masaaki, Ikeda, Nobukazu, Yamaji, Michio
• Granted Patent: US 10,371,630 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01N 2021/3148 using three or more wavelengths
• CPC Class Codes: G01N 2021/5969 Scanning of a tube, a cuvette, a volume of sample
• CPC Class Codes: G01N 2021/8411 Application to online plant, process monitoring
• CPC Class Codes: G01N 2021/8578 Gaseous flow IR analysers G01N21/8507
• CPC Class Codes: G01N 21/33 using ultraviolet light G01N21/39 takes precedence
• CPC Class Codes: G01N 21/5907 Densitometers
• CPC Class Codes: G01N 2201/0627 Use of several LED's for spectral resolution
• CPC Class Codes: G01N 2201/0691 Modulated (not pulsed supply)

Abstract

An inline concentration meter includes a light source unit emitting mixed light containing at least two wavelengths with a phase difference, a detecting unit including a light incident part for entering the mixed light emitted from the light source unit into a fluid passage of a detector body and at least two light detection parts receiving the mixed light passed through the fluid passage, a computing processor unit conducting frequency analyses of detection signals of the mixed light output from the respective light detection parts and computing variations of intensities of the detection signals corresponding to absorbances in at least two frequency ranges to compute a concentration of fluid in the fluid passage based on the variations of the intensities of the detection signals, and a recording/displaying unit recording and displaying a value of the fluid concentration computed at the computing processor unit.

Claims

1. An inline concentration meter, comprising:

a light source unit for emitting mixed light containing at least two wavelengths with a phase difference;

a detecting unit including a light incident part for entering the mixed light emitted from the light source unit into a fluid passage of a detector body and at least two light detection parts for receiving the mixed light passed through the fluid passage;

a computing processor unit for conducting frequency analyses of detection signals of the mixed light output from the respective light detection parts and computing variations of intensities of the detection signals corresponding to absorbances in at least two frequency ranges to compute a concentration of fluid in the fluid passage based on the variations of the intensities of the detection signals in the at least two frequency ranges; and

a recording/displaying unit for recording and displaying a value of the fluid concentration computed at the computing processor unit.

2. The inline concentration meter according to claim 1, wherein the light source unit emits mixed light containing three wavelengths.

3. The inline concentration meter according to claim 1, wherein the light source unit has an LED or laser diode as a light source.

4. The inline concentration meter according to claim 1, wherein the light source unit emits ultraviolet light in a wavelength region of 200 to 400 nm.

5. The inline concentration meter according to claim 1, wherein the computing processor unit conducts the frequency analyses through Fourier transformation or wavelet transformation.

6. The inline concentration meter according to claim 1, wherein the computing processor unit computes a concentration of organic metal raw material gas included in the mixed gas flowing in the fluid passage.

7. The inline concentration meter according to claim 1, wherein the detecting unit comprises one light incident part and two light detection parts.

8. The inline concentration meter according to claim 1, wherein the light source unit emits mixed ultraviolet light of three ultraviolet lights with different wavelengths.

9. The inline concentration meter according to claim 1, wherein the computing processor unit respectively conducts the frequency analysis of detection signals of the mixed light containing three wavelengths through Fourier transformation.

10. The inline concentration meter according to claim 7, wherein the one light incident part is arranged on one side of the detector body and the two light detection parts are arranged on other one side opposing to the one side.

11. The inline concentration meter according to claim 2, wherein the one light incident part is arranged on one side of the detector body and three light detection parts are arranged on other one side opposing to the one side.

12. The inline concentration meter according to claim 7, wherein the one light incident part and one light detection part are arranged on one side of the detector body and the two light detection parts are arranged on other one side opposing to the one side.

13. The inline concentration meter according to claim 1, wherein the light source unit emits mixed light that a beam combiner provides by combining ultraviolet lights with different wavelengths.

14. A concentration detection method comprising the steps of:

entering mixed light of three ultraviolet lights having different wavelengths with phase differences emitted from a light source unit from one light incident part arranged on a detector body with a fluid passage into the fluid passage;

detecting the respective ultraviolet lights passed through the fluid passage by at least two light detection parts arranged on the detector body;

conducting frequency analyses of detection signals of the mixed light detected by the respective light detection parts;

computing variations of intensities of the detection signals detected by the light detection parts corresponding to absorbances in three frequency ranges; and

computing a concentration of organic metal material gas included in mixed gas that flows through the fluid passage based on the at least six computed variations of the intensities of the detection signals in the three frequency ranges.

15. The concentration detection method according to claim 14, wherein the number of the light detection part is three and the concentration of the organic metal material gas included in the mixed gas that flows through the fluid passage is computed based on nine computed variations of intensities corresponding to the absorbances.

16. The concentration detection method according to claim 14, wherein the mixed light entering from the light incident part is detected by the one light detection part and reflected light from the light detection part is entered to the another light detection part.

17. The concentration detection method according to claim 14, wherein the mixed light entering from the light incident part is dispersed and entered to the two light detection parts.