JP3566840B2 - Concentration measuring device - Google Patents

Concentration measuring device Download PDF

Info

Publication number
JP3566840B2
JP3566840B2 JP28772897A JP28772897A JP3566840B2 JP 3566840 B2 JP3566840 B2 JP 3566840B2 JP 28772897 A JP28772897 A JP 28772897A JP 28772897 A JP28772897 A JP 28772897A JP 3566840 B2 JP3566840 B2 JP 3566840B2
Authority
JP
Japan
Prior art keywords
light intensity
light
sample
detector
scattered
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
JP28772897A
Other languages
Japanese (ja)
Other versions
JPH11108822A (en
Inventor
達夫 伊串
了 昼田
清 森本
靖 渡邊
Original Assignee
株式会社堀場製作所
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 株式会社堀場製作所 filed Critical 株式会社堀場製作所
Priority to JP28772897A priority Critical patent/JP3566840B2/en
Publication of JPH11108822A publication Critical patent/JPH11108822A/en
Application granted granted Critical
Publication of JP3566840B2 publication Critical patent/JP3566840B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Images

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an apparatus for measuring the concentration of particles in a gas phase, particles or a colloid in a liquid, and the like.
[0002]
[Prior art]
For example, as a method for measuring the particle concentration in a liquid, there is a method using turbidity. The measurement of the sample concentration based on the turbidity is performed by calibrating a turbidity measuring device in advance for a specific sample as described in JIS K0801, measuring the turbidity using the calibrated device, and measuring the turbidity. Is used to determine the concentration.
[0003]
[Problems to be solved by the invention]
However, when measuring a sample other than the calibration sample, in order to measure the concentration, it is necessary to re-calibrate the apparatus using the sample to be measured. Since turbidity is a phenomenon due to scattering caused by particles contained in a sample, there are a particle diameter and a relative refractive index as turbidity parameters, but calibration data has such parameters. This is because it is necessary to have calibration data for each sample.
[0004]
That is, the above conventional concentration measuring how, must have a calibration curve of the concentration turbidity (calibration curve) by the number of samples, the operation for obtaining the calibration curve was very troublesome. Further, the concentration of the obtained sample was a concentration converted into a standard sample, and was not an actual concentration of the sample itself.
[0005]
SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned matters, and an object of the present invention is to provide a concentration measuring device capable of easily obtaining the actual concentration of a sample in a short time.
[0006]
[Means for Solving the Problems]
To achieve the above object, a concentration measuring device comprising a light source for irradiating light to the sample cell, when irradiated with light from the light source to the sample cell, for detecting the transmitted light transmitted through the sample cell a measurement unit which includes a detector that transmitted light intensity detector and by arranging a plurality of sensor elements consisting of a scattered light intensity detector for detecting scattered light scattered by the sample particles in the sample cell, the detector Light intensity signals output from the two light intensity detectors are input, and a signal processing unit that performs a predetermined calculation based on the light intensity signals is provided.The signal processing unit includes a scattered light intensity detector. while you calculating the scattered light equivalent particle size distribution based on the scattered light intensity distribution by the scattered light of the light intensity signals output from the plurality of sensor elements, it is output from the transmitted light intensity detector and the incident light intensity for the sample cell that Toru Based on the optical path length of the light intensity and the sample cell is calculated turbidity, and samples from the those calculated scattered light equivalent particle size distribution, turbidity and, the relationship between the scattering coefficient and the grain size obtained in advance It is characterized in that it is configured to calculate the density.
[0007]
[0008]
According to the present invention, on the occasion to measure the concentration of the sample, light is irradiated to the sample in the sample cell, and the intensity distribution of the scattered light generated at that time, based on the transmitted light intensity and the optical path length and the incident light intensity And turbidity calculated at the same time. By calculating the particle size distribution from the scattered light intensity distribution, a scattered light equivalent particle size distribution of the sample can be obtained. By using the scattered light equivalent particle size distribution and turbidity, and the relationship between the scattering coefficient and the particle size determined in advance, without using a calibration curve of concentration and turbidity, and even if the particle size changes The sample concentration can be obtained.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiments of the present invention will be described with reference to the drawings. 1 to 3 show one embodiment of the present invention. First, FIG. 1 shows an example become (also referred to as the particle size distribution) laser diffraction particle size distribution measuring equipment of the concentration measuring apparatus of the present invention, in this figure, the following member by A measuring unit Consists of That is, reference numeral 1 denotes a dispersion bus, in which a stirring blade 3 rotated by a motor 2 is provided, and an ultrasonic vibrator 4 vibrated by an oscillator (not shown) is provided outside the bottom surface 1a. . Reference numeral 5 denotes a tank containing a dispersion medium 6 containing sample particles, and reference numeral 7 denotes a dispersion medium supply pipe, which is provided with an on-off valve 8 such as an electromagnetic valve, and is openly connected to the opening of the dispersion bath 1.
[0010]
Reference numeral 9 denotes a flow cell as a sample cell to be filled with the suspension, which is connected to the dispersion bus 1 by a circulation path 12 having a pump 10 and a switching valve 11. Reference numeral 13 denotes a laser light source provided on one side of the flow cell 9. The laser light emitted from the laser light source 13 reaches the beam expander 15 via the reflecting mirrors 14a and 14b, and becomes parallel light having a predetermined beam diameter. Irradiation is performed on the flow cell 9.
[0011]
Reference numeral 16 denotes a condensing lens provided on the other side of the flow cell 9, and an array of detectors 17 is disposed at a focal position behind the condensing lens. As shown in FIG. 2, the arrayed detector 17 includes a transmitted light intensity detector 17A that detects light transmitted through the flow cell 9, and a semi-ring shape having different radii from the transmitted light intensity detector 17A. And a scattered light intensity detector 17B in which a plurality of sensor elements 17b having a light receiving surface are concentrically arranged.
[0012]
In FIG. 1, B is a signal processing unit, which is composed of the following members. That is, 18 is a signal switching circuit including an amplifier and a multiplexer, and 19 is an AD converter. Reference numeral 20 denotes a signal operation unit composed of, for example, a CPU, which performs various controls on each unit of the apparatus, and converts a signal of the detector 17 input via the AD converter 19 based on a program or data stored in the ROM 21. Then, a particle size distribution (particle size distribution) calculation and a turbidity calculation are performed, and the calculation result is stored in the RAM 22. Reference numeral 23 denotes a display operation unit provided with various function keys 23b around a display screen 23a formed of a CRT or the like, and reference numeral 24 denotes a printer that outputs a calculation result.
[0013]
In the laser diffraction type particle size distribution measuring apparatus having the above-described configuration, a laser beam is emitted from the laser light source 13 to the flow cell 9 while the suspension is being supplied to the flow cell 9. A part of the laser light applied to the flow cell 9 passes through the suspension and does not hit the sample particles, and is transmitted to the opposite side of the flow cell 9. This transmitted light enters the transmitted light intensity detector 17A in the detector 17 via the condenser lens 16. A light intensity signal is output from the transmitted light intensity detector 17A based on the incidence of the transmitted light, sent to the AD converter via the signal switching circuit 18, and taken into the signal operation unit 20.
[0014]
On the other hand, another part of the laser light irradiated to the flow cell 9 becomes light scattered by the sample particles contained in the suspension. This scattered light enters the scattered light intensity detector 17B of the detector 17 at each scattering angle via the condenser lens 16. In this case, the light having the same scattering angle as the light scattered by the sample particles enters the position of the same radius on the scattered light intensity detector 17B by the action of the condenser lens 16. Therefore, light incident on the same sensor element 17b of the scattered light intensity detector 17 B, the scattering light is only very close optical output signal from each sensor element 17b represents a light intensity signal for each scattering angle, each sensor A scattered light intensity distribution is obtained from the output signal of each element 17b, sent to the AD converter 19 via the signal switching circuit 18, and taken into the signal operation unit 20.
[0015]
By the way, the attenuation of transmitted light due to powder or colloid in the cell is expressed by the following equation (1).
τT = ln (I 0 / I) / L (1)
Here, I and I 0 are the intensity of the incident light and the transmitted light, respectively, L is the optical path length of the cell, and τT is the turbidity.
[0016]
Therefore, the signal operation unit 20 can obtain the turbidity τT of the suspension by using the above equation (1), the incident light intensity of the laser light, the transmitted light intensity, and the optical path length of the cell 9. .
[0017]
Further, in the signal calculation unit 20, the particle size distribution is calculated all at once by a calculation using a preset conversion coefficient matrix for converting the intensity distribution of the scattered light into a particle size distribution (particle size distribution). Note that a conversion coefficient matrix is prepared for each relative refractive index of the target sample.
[0018]
Next, a procedure for obtaining the density will be described. Assuming that the scattering coefficient of light per particle is Kext, the particle volume concentration is Φ, and the particle diameter is a, the turbidity τT / Φ per unit volume is
τT / Φ = (3π / 4a) · Kext (2)
It becomes.
[0019]
Therefore, the particle volume concentration Φ is
Φ = {4a / (3πLKext)} · ln (I 0 / I) (3)
It can be expressed as.
[0020]
The scattering coefficient Kext of light per particle can be theoretically obtained from Mie's scattering equation when the particles are uniform and spherical. FIG. 3 is a diagram showing an example of the relationship between the scattering coefficient and the particle diameter, and the symbol A indicates the scattering cross section (or light shielding efficiency).
[0021]
In this case, when the cell used for the measurement (the flow cell 9 in this example) and the sample are constant, the optical path length L of the cell, the light scattering coefficient Kext per particle, and the particle diameter a are constant. It is the same as the turbidity measurement method.
[0022]
If the particle diameter has a distribution, and the particle diameter distribution is f (a), the light scattering coefficient Kaext at that time can be expressed by the following equation (4).
[0023]
(Equation 1)
[0024]
In the above (4), a 0 is the minimum particle size, also, a n denotes the maximum particle size, respectively.
[0025]
Therefore, as described above, for a sample having a particle size distribution, Kaext is used instead of Kext in the equation (3).
[0026]
Then, the sample volume concentration is obtained by calculation from the scattering coefficient when there is a particle size distribution using the measured turbidity. The scattering coefficient is obtained in advance for each refractive index of the sample to be measured, and is stored.
[0027]
As can be understood from the above description, the concentration measuring method of the present invention can calculate the sample concentration from one piece of calibration data by calculation even if the particle size distribution and the type of the sample change. Is no longer required, and the measurement can be performed in a shorter time and more easily than in the conventional technique. In the concentration measurement method, the actual concentration of the sample to be measured can be obtained, and the concentration can be measured even in a sample measurement system in which the distribution of particles in the sample is not uniform and changes. Was.
[0028]
The present invention is not limited to the above-described embodiment, and can be implemented in various modifications. For example, in addition to powders and colloids dispersed in a liquid, Powder may be dispersed. When the sample is a powder or a colloid dispersed in a liquid, a cell 25 as shown in FIG.
[0029]
【The invention's effect】
According to the present invention, the actual concentration of the sample can be obtained in a short time and easily. Further, in the present invention, there is also an advantage can therefore be found to concentration using the apparatus for particle size distribution measurement.
[Brief description of the drawings]
1 is a diagram schematically showing a configuration of a density measurement apparatus of the present invention.
FIG. 2 is a diagram schematically showing an example of a detector used in the device.
FIG. 3 is a diagram illustrating an example of a relationship between a scattering coefficient and a particle diameter.
4 is a diagram schematically showing another configuration of the concentration measurement apparatus of the present invention.
[Explanation of symbols]
A: measuring unit, B: signal processing unit, 9: sample cell, 13: light source , 17: detector, 17A: transmitted light intensity detector, 17B: scattered light intensity detector, 17b: sensor element.

Claims (1)

  1. A light source that irradiates the sample cell with light , and a light intensity detector that detects transmitted light transmitted through the sample cell when the light from the light source irradiates the sample cell, and a plurality of sensor elements are arranged. a measuring unit having a detector consisting of a scattered light intensity detector for detecting scattered light scattered by the sample particles of the sample cell, light intensity signals output from the two light intensity detectors in the detector input And a signal processing unit that performs a predetermined operation based on the signal processing unit .
    The signal processing unit, while you calculating the scattered light equivalent particle size distribution based on the scattered light intensity distribution by the scattered light of the light intensity signals output from the plurality of sensor elements of the scattered light intensity detector, with respect to the sample cell The turbidity is calculated based on the incident light intensity, the transmitted light intensity output from the transmitted light intensity detector, and the optical path length of the sample cell , and the calculated scattered light equivalent particle size distribution, turbidity, and concentration measuring apparatus and a relationship between the scattering coefficient and the grain size had been determined and characterized by having a signal calculator for calculating the sample concentration.
JP28772897A 1997-10-04 1997-10-04 Concentration measuring device Expired - Fee Related JP3566840B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP28772897A JP3566840B2 (en) 1997-10-04 1997-10-04 Concentration measuring device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP28772897A JP3566840B2 (en) 1997-10-04 1997-10-04 Concentration measuring device

Publications (2)

Publication Number Publication Date
JPH11108822A JPH11108822A (en) 1999-04-23
JP3566840B2 true JP3566840B2 (en) 2004-09-15

Family

ID=17720990

Family Applications (1)

Application Number Title Priority Date Filing Date
JP28772897A Expired - Fee Related JP3566840B2 (en) 1997-10-04 1997-10-04 Concentration measuring device

Country Status (1)

Country Link
JP (1) JP3566840B2 (en)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5277432B2 (en) * 2007-07-17 2013-08-28 学校法人日本大学 Suspended matter analysis method
JP5891936B2 (en) * 2011-05-10 2016-03-23 三菱化学株式会社 Apparatus and method for measuring solvent insoluble content of coal tar or coal tar pitches
EP2863206A4 (en) * 2012-06-14 2016-05-11 Nanjing Tuozhu Pharmaceutical & Tech Co Ltd Endotoxin detection systems and detection methods thereof
CN104422640B (en) * 2013-09-06 2017-01-25 重庆大学 Laser-scattering-based air quality detecting system
CN104833624A (en) * 2015-05-20 2015-08-12 浙江科技学院 Fiber-based turbidity measuring method and apparatus
JP6872558B2 (en) * 2016-11-16 2021-05-19 株式会社堀場製作所 Particle size distribution measuring device, particle size distribution measuring method, and program for particle size distribution measuring device

Also Published As

Publication number Publication date
JPH11108822A (en) 1999-04-23

Similar Documents

Publication Publication Date Title
JP2771206B2 (en) Portable particle analyzer
US6417920B1 (en) Particle size analyzer based on laser diffraction method
EP0167272B1 (en) Particle size measuring apparatus
US4140395A (en) Electro-optical method and system for in situ measurements of particle size and distribution
US4027973A (en) Detector apparatus for laser light scattering photometers
US6252658B1 (en) Particle size distribution measuring apparatus
JP3566840B2 (en) Concentration measuring device
EP0956496B1 (en) Method and apparatus for detecting an object
JP3446410B2 (en) Laser diffraction particle size distribution analyzer
JP2006010353A (en) Fine particle measuring instrument
US6104491A (en) System for determining small particle size distribution in high particle concentrations
JP2910596B2 (en) Particle size distribution analyzer
US6104490A (en) Multiple pathlength sensor for determining small particle size distribution in high particle concentrations
JP3531557B2 (en) Laser diffraction / scattering particle size distribution analyzer
JP3151036B2 (en) Method and apparatus for detecting submicron particles
US5126581A (en) Particle measurement method and apparatus for determining corrected particle diameter
JP3058571B2 (en) Particle size distribution analysis method
Bunkin et al. Small-angle scattering of laser radiation by stable micron particles in twice-distilled water
JPH03154850A (en) Specimen inspecting device
JP3235554B2 (en) Laser diffraction / scattering particle size distribution analyzer
JP2000002644A (en) Laser diffraction/scattering type grain size distribution- measuring device
JP2803296B2 (en) Particle size distribution analyzer
CN108844866B (en) Nanoparticle tracking device
Schwarz et al. Investigations on the Capability of the Statistical Extinction Method for the Determination of Mean Particle Sizes in Concentrated Particle Systems
JP4294384B2 (en) Particle size distribution measuring device

Legal Events

Date Code Title Description
A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20040120

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20040312

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20040608

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20040611

R150 Certificate of patent or registration of utility model

Free format text: JAPANESE INTERMEDIATE CODE: R150

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20100618

Year of fee payment: 6

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20100618

Year of fee payment: 6

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20110618

Year of fee payment: 7

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20110618

Year of fee payment: 7

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20120618

Year of fee payment: 8

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20120618

Year of fee payment: 8

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20120618

Year of fee payment: 8

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20130618

Year of fee payment: 9

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20130618

Year of fee payment: 9

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20130618

Year of fee payment: 9

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

LAPS Cancellation because of no payment of annual fees