阅读说明：本技术 浊度检测方法 (Turbidity detection method ) 是由 周文杰 付聪 许涛 邵晨佳 朱伟健 徐风宁 万永杰 廖昌义 唐怀武 于 2021-07-21 设计创作，主要内容包括：本发明提供了一种浊度检测方法,所述浊度检测方法包括以下步骤：(A1)光源发出的测量光进入样品池内,测量光在待测液体中散射；(A2)环绕所述样品池的多个探测器接收散射光信号A-(i),i＝1,2···N,N为大于2的整数；(A3)判断所述散射光信号是否处于设定范围内；如结果为是,进入下一步骤,如为否,返回到步骤(A2)；(A4)判断单个或若干组散射光信号的偏差和误差是否小于阈值；如结果为是,进入下一步骤,如为否,返回到步骤(A2)；(A5)获得单次检测中所有散射光信号A-(i)的平均值；(A6)根据所述平均值以及映射关系获得待测液体的浊度。本发明具有准确性好等优点。(The invention provides a turbidity detection method, which comprises the following steps: (A1) measuring light emitted by the light source enters the sample cell and is scattered in the liquid to be measured; (A2) receiving scattered light signals A by a plurality of detectors surrounding the sample cell i N is an integer greater than 2; (A3) judging whether the scattered light signal is in a set range; if yes, entering the next step, if no, returning to the step (A2); (A4) judging whether the deviation and the error of a single or a plurality of groups of scattered light signals are smaller than a threshold value; if yes, entering the next step, if no, returning to the step (A2); (A5) obtaining all scattered light signals A in a single detection i Average value of (d); (A6) and obtaining the turbidity of the liquid to be measured according to the average value and the mapping relation. The method has the advantages of good accuracy and the like.)

1. A turbidity detection method, comprising the steps of:

(A1) measuring light emitted by the light source enters the sample cell and is scattered in the liquid to be measured;

(A2) receiving scattered light signals A by a plurality of detectors surrounding the sample cell_iN is an integer greater than 2;

(A3) judging whether the scattered light signal is in a set range;

if yes, entering the next step, if no, returning to the step (A2);

(A4) judging whether the deviation and the error of a single or a plurality of groups of scattered light signals are smaller than a threshold value;

if yes, entering the next step, if no, returning to the step (A2);

(A5) obtaining all scattered light signals A in a single detection_iAverage value of (d);

(A6) and obtaining the turbidity of the liquid to be measured according to the average value and the mapping relation.

2. A turbidity detecting method according to claim 1, wherein the liquid to be measured is introduced into said sample cell from the bottom up.

3. A turbidity detecting method according to claim 1, wherein in the step (a4), the judgment of the deviation and the error comprises the steps of:

(B1) determining each scattered light signal A_iIs less than a first threshold;

if yes, entering the next step, if no, returning to the step (A2);

(B2) averagely grouping the detectors, wherein the number of each group is P, judging whether the relative standard of the sum of the scattered light signals of each group is smaller than a second threshold value or not, and the number of the detectors corresponding to the scattered light signals of each group is the same;

if yes, entering the next step, if no, returning to the step (A2);

(B3) judging whether the relative error of each group of scattered light signals is smaller than a threshold value or not, wherein the number of detectors corresponding to each group of scattered light signals is the same;

if the results are both yes, the next step is entered, if no appears in the results, the step is returned to (A2).

4. A method of turbidity measurement according to claim 3, wherein step (B3) is specifically:

(C1) judging whether the relative error of each scattered light signal in each group of scattered light signals is smaller than a third threshold value;

if yes, entering the next step, if no, returning to the step (A2);

(C2) averagely grouping the detectors, wherein the number of each group is Q, and P is less than Q, and judging whether the relative error of the sum of the scattered light signals of each group is less than a fourth threshold value or not;

if the results are both yes, the next step is entered, if no appears in the results, the step is returned to (A2).

5. A turbidity assay according to claim 4, wherein P-2 and the detectors are two detectors which are centrosymmetric with respect to the measurement light.

6. A turbidity detecting method according to claim 1, wherein in the step (a6), a plurality of average values detected a plurality of times in one measurement period are obtained, the maximum value and the minimum value thereof are removed, and the average value of the remaining values is calculated.

7. A method according to claim 6, wherein if the number of remaining averages is less than a fifth threshold, an indication is made that the number of bubbles in the liquid being measured is out of specification.

8. A method of turbidity measurement according to claim 1, wherein N-8, the detector uniformly surrounds the measurement light.

9. A turbidity detection method according to claim 1, wherein said mapping relationship is:

C＝0.000006A²+0.00003A-0.004, C is the haze value and A is the mean value.

10. A method of turbidity detection according to claim 1, wherein the normal of the light-sensitive surface of said probe is perpendicular to said measuring light.

Technical Field

The invention relates to liquid detection, in particular to a turbidity detection method.

Background

The measurement of low-range turbidity belongs to the field of difficult water quality measurement, particularly below 1 NTU. For low-range turbidity detection, the main measurement method is to emit light by a light source, the light is irradiated on a turbidity substance to be scattered and then scattered on a detector, and the signal value detected by the detector is in direct proportion to the turbidity. The difficulty of low-range turbidity measurement mainly lies in that when the turbidity in a water body is very small, the measurement is particularly interfered greatly, and the main interference factor is air bubbles in the water. A small bubble can scatter the light, with consequent large variations in the measured values. At present, the international low-range mainstream products include:

a 1720E low range turbidity analyser from HACH company, the solution to the bubble problem is: the measuring cell is enlarged to remove bubbles, some bubbles can be removed to a certain extent, but all bubbles, especially small bubbles, are difficult to remove;

a low range turbidity analyzer from SWAN corporation, the solution to the bubble problem is: this method is also unreliable by changing the water pressure and flow rate in an attempt to flush out the bubbles.

Disclosure of Invention

In order to overcome the defects in the prior art, the invention provides a turbidity detection method.

The purpose of the invention is realized by the following technical scheme:

a turbidity detection method, comprising the steps of:

(A1) measuring light emitted by the light source enters the sample cell and is scattered in the liquid to be measured;

(A2) receiving scattered light signals A by a plurality of detectors surrounding the sample cell_iN is an integer greater than 2;

(A3) judging whether the scattered light signal is in a set range;

if yes, entering the next step, if no, returning to the step (A2);

(A4) judging whether the deviation and the error of a single or a plurality of groups of scattered light signals are smaller than a threshold value;

if yes, entering the next step, if no, returning to the step (A2);

(A5) obtaining all scattered light signals A in a single detection_iAverage value of (d);

(A6) and obtaining the turbidity of the liquid to be measured according to the average value and the mapping relation.

Compared with the prior art, the invention has the beneficial effects that:

1. low-range detection is realized;

the interference of bubbles in the liquid to be detected is eliminated by utilizing a plurality of detectors surrounding the measuring light and a data processing mode based on the detectors, for example, the group of data is abandoned or the data is detected again, so that the detection sensitivity is improved, and the low-range detection is realized;

2. the detection precision is high;

the provision of the mapping relation further improves the detection accuracy and realizes low-range detection;

the liquid to be measured enters the sample cell from bottom to top, so that the generation of bubbles is remarkably reduced.

Drawings

The disclosure of the present invention will become more readily understood with reference to the accompanying drawings. As is readily understood by those skilled in the art: these drawings are only for illustrating the technical solutions of the present invention and are not intended to limit the scope of the present invention. In the figure:

FIG. 1 is a flow chart of a turbidity detection method according to an embodiment of the present invention.

Detailed Description

Fig. 1 and the following description depict alternative embodiments of the invention to teach those skilled in the art how to make and reproduce the invention. Some conventional aspects have been simplified or omitted for the purpose of teaching the present invention. Those skilled in the art will appreciate that variations or substitutions from these embodiments will be within the scope of the invention. Those skilled in the art will appreciate that the features described below can be combined in various ways to form multiple variations of the invention. Thus, the present invention is not limited to the following alternative embodiments, but is only limited by the claims and their equivalents.

Example 1:

fig. 1 schematically shows a flow chart of a turbidity detecting method according to an embodiment of the present invention, which includes the following steps, as shown in fig. 1:

(A1) measuring light emitted by the light source enters the sample cell and is scattered in the liquid to be measured;

(A2) receiving scattered light signals A by a plurality of detectors surrounding the sample cell_iN is an integer greater than 2;

(A3) judging whether the scattered light signal is in a set range;

if yes, entering the next step, if no, returning to the step (A2);

(A4) judging whether the deviation and the error of a single or a plurality of groups of scattered light signals are smaller than a threshold value;

if yes, entering the next step, if no, returning to the step (A2);

(A5) obtaining all scattered light signals A in a single detection_iAverage value of (d);

(A6) and obtaining the turbidity of the liquid to be measured according to the average value and the mapping relation.

In order to reduce the generation of bubbles, the liquid to be measured further enters the sample cell from bottom to top.

In order to reduce the influence of the bubbles, further, in the step (a4), the error determination includes the steps of:

(B1) determining each scattered light signal A_iIs less than a first threshold;

if yes, entering the next step, if no, returning to the step (A2);

(B2) averagely grouping the detectors, wherein the number of each group is P, judging whether the relative standard of the sum of the scattered light signals of each group is smaller than a second threshold value or not, and the number of the detectors corresponding to the scattered light signals of each group is the same;

if yes, entering the next step, if no, returning to the step (A2);

(B3) judging whether the relative error of each group of scattered light signals is smaller than a threshold value or not, wherein the number of detectors corresponding to each group of scattered light signals is the same;

if the results are both yes, the next step is entered, if no appears in the results, the step is returned to (A2).

In order to further reduce the influence of the bubbles on the detection, further, the step (B3) is specifically:

(C1) judging whether the relative error of each scattered light signal in each group of scattered light signals is smaller than a third threshold value;

if yes, entering the next step, if no, returning to the step (A2);

(C2) averagely grouping the detectors, wherein the number of each group is Q, and P is less than Q, and judging whether the relative error of the sum of the scattered light signals of each group is less than a fourth threshold value or not;

if the results are both yes, the next step is entered, if no appears in the results, the step is returned to (A2).

In order to increase the detection sensitivity, P is 2, and the detectors are two detectors that are symmetrical with respect to the measurement light.

In order to improve the detection accuracy, further, in step (a6), a plurality of average values obtained by a plurality of detections in one measurement period are obtained, the maximum value and the minimum value are removed, and the average value of the remaining values is calculated.

In order to accurately judge whether the bubbles in the liquid to be detected exceed the standard, further, if the number of the remaining average values is smaller than a fifth threshold, the number of the bubbles in the liquid to be detected is prompted to exceed the standard.

In order to reduce the influence of external light, further, the normal of the light sensing surface of the detector is perpendicular to the measuring light.

Example 2:

an example of the application of the turbidity measuring method of example 1 of the present invention to water quality analysis.

In this application example, the turbidity detection method includes the steps of:

(A1) the liquid to be measured enters the sample cell from bottom to top, the measuring light emitted by the light source enters the sample cell, and the measuring light is scattered in the liquid to be measured;

(A2) receiving scattered light signals A by 8 detectors uniformly surrounding the sample cell_iN is an integer greater than 2, and a normal of a light sensing surface of the detector is perpendicular to the measuring light;

(A3) judging whether the 8 scattered light signals are all in a set range, such as the set range is more than 100 and less than 6000;

if yes, entering the next step, if no, returning to the step (A2);

(A4) judging whether the deviation and the error of the single or a plurality of groups of scattered light signals are smaller than a threshold value, wherein the judgment of the deviation and the error is as follows:

(B1) judging 8 scattered light signals A_iIs less than a first threshold value: 50 percent;

if yes, entering the next step, if no, returning to the step (A2);

(B2) averagely grouping the detectors, wherein two detectors which are centrosymmetric about the measuring light are in one group, and dividing into 4 groups in total, namely the number of each group is P-2, and judging whether the relative standard of the sum of the scattered light signals of each group is less than a second threshold value: 30%, the number of detectors corresponding to each group of scattered light signals is the same;

if yes, entering the next step, if no, returning to the step (A2);

(B3) judging whether the relative error of the 4 groups of scattered light signals is smaller than a threshold value, wherein the number of detectors corresponding to each group of scattered light signals is the same, and the specific judgment mode is as follows:

(C1) judging whether the relative error of each scattered light signal in the 4 groups of scattered light signals is smaller than a third threshold value: 20 percent;

if yes, entering the next step, if no, returning to the step (A2);

(C2) averagely grouping the detectors, wherein 4 detectors are a group, the number of the detectors in each group is 2, Q is 4, P is less than Q, and judging whether the relative error of the sum of the 2 groups of scattered light signals is less than a fourth threshold value: 15 percent;

if yes, entering the next step, if no, returning to the step (A2);

(A5) obtaining all scattered light signals A in a single detection_iAverage value of (d);

(A6) obtaining the turbidity of the liquid to be measured according to the average value and the mapping relation in a specific mode that:

obtaining a plurality of average values obtained by a plurality of detections in a measurement period, removing the maximum value and the minimum value, and calculating to obtain the average value of the rest values;

in this embodiment, a measurement period is 1 minute, data is collected every 4 seconds, that is, 15 sets of data are obtained in one measurement period, data satisfying the step (A3) (a4) is obtained, the number of average values in the step (a5) is not higher than 15, two maximum values and two minimum values of the average values are removed, if the number of average values of remaining values (i.e., remaining 11 average values) is smaller than a fifth threshold, it is suggested that the number of bubbles in the liquid to be measured exceeds a standard, and if the number of remaining average values is not smaller than the fifth threshold, the average value of the remaining values is obtained, and the turbidity of the liquid to be measured is obtained according to the following mapping relationship:

C＝0.000006A²+0.00003A-0.004, C is the haze value and A is the average of the remaining values.