Novel ultra-low silicon content testing system

Abstract

The invention discloses a novel ultra-low silicon content test system, which relates to the technical field of analysis and test, and comprises a control unit, a power supply, a test unit, a pump set, a colorimetric pool, an overflow pool and a pressure release valve, the pump set comprises three standard peristaltic pumps and is used for conveying water samples and reagents; the colorimetric pool adopts a special structure, and a metal pipe is connected with a peek pipeline and is matched with an optical fiber for use; the test unit is provided with a specific photodiode and a light-emitting diode to eliminate interference; acquiring a detection signal through a specific operation process, and calculating the content of the silicon element according to a preset formula; the metal tube cuvette is used to realize long optical path and low reagent consumption, a double-lamp three-PD optical configuration scheme is matched with a compensation formula to effectively eliminate bubble interference and electrical drift, and ultralow silicon content can be measured more accurately.

Description

Technical Field

[0001] The present invention relates to the technical field of analytical testing, and specifically to a new ultra-low silicon content testing system. Background Art

[0002] In the fields of modern industrial production and scientific research experiments, the quality control of ultrapure water is of crucial importance. As a key indicator for measuring the purification ability of ultrapure water machines, the accurate measurement of the silicon content in water is the core link to ensure that ultrapure water meets various usage requirements. In some advanced scientific research experiment scenarios such as semiconductor manufacturing and high-end electronic equipment production, the control of the silicon content in ultrapure water is particularly important, and even a slight deviation may lead to the failure of the experiment.

[0003] In recent years, with the continuous improvement of the requirements for the purity of ultrapure water in various industries, the difficulty of measuring low levels of silicon in ultrapure water has become increasingly prominent. Currently, the wet chemical method is generally used to measure the silicon content in water. When facing low silicon content, especially when the silicon content is at an extremely low level, the absorbance value is extremely small, and it is difficult to accurately obtain data using this traditional measurement method.

[0004] To address this problem, the industry has proposed two main solutions. The first solution is to concentrate the sample water first, then use the wet chemical method for measurement, and finally calculate the original silicon content of the sample water according to a multiple. In this solution, the concentration unit is not only large in volume, occupying a large amount of space, but also high in cost, which undoubtedly greatly increases the detection cost and limits its wide application in actual production and scientific research. The second solution is to increase the size of the cuvette and the optical path to improve the accuracy of absorbance measurement, but the large cuvette leads to a sharp increase in reagent consumption, and reagents need to be added frequently. This not only increases the complexity of the operation and labor costs, but also easily affects the measurement progress and accuracy due to problems such as untimely reagent addition. Therefore, there is an urgent need to develop a new ultra-low silicon content testing system to solve the above problems. Summary of the Invention

[0005] The purpose of the present invention is to provide a new ultra-low silicon content testing system to solve the problems raised in the prior art.

[0006] To achieve the above purpose, the present invention provides the following technical solution: A new ultra-low silicon content testing system, the testing system includes: a control unit, a power supply, a testing unit, a pump group, a colorimetric cell, a mixing cell, an overflow cell, and a pressure relief valve;

[0007] The testing unit is connected to the colorimetric cell; the pump group is respectively connected to the mixing cell, the overflow cell, and the pressure relief valve; the colorimetric cell is connected to the mixing cell; the overflow cell is respectively connected to the pressure relief valve.

[0008] Further, the pump set includes three standard peristaltic pumps. Among them, the main hose of the first standard peristaltic pump is connected to the first end of the liquid mixing tank, and the auxiliary hose of the first standard peristaltic pump is connected to the pressure relief valve; the main hose of the second standard peristaltic pump is connected to the second port of the liquid mixing tank, and the auxiliary hose of the second standard peristaltic pump is connected to the pressure relief valve; the main hose of the third standard peristaltic pump is connected to the third end of the liquid mixing tank, and the auxiliary hose of the third standard peristaltic pump is connected to the overflow tank.

[0009] Further, the colorimetric cell includes a first PEEK pipeline, a second PEEK pipeline, a first optical fiber, a second optical fiber, and a metal tube. Among them, the first end of the first optical fiber is connected to the first end of the first PEEK pipeline; the first end of the second optical fiber is connected to the first end of the second PEEK pipeline; the metal tube connects the second ends of the first PEEK pipeline and the second PEEK pipeline.

[0010] Further, the test unit includes a photodiode PD1, a photodiode PD2, a photodiode PD3, a light-emitting diode LED1, and a light-emitting diode LED2. Among them, the photodiode PD2 and the photodiode PD3 are connected to the second end of the first optical fiber; the photodiode PD3, the light-emitting diode LED1, and the light-emitting diode LED2 are connected to the second end of the second optical fiber;

[0011] The light of the above-mentioned light-emitting diode LED1 and light-emitting diode LED2 is transmitted through the second optical fiber into the metal tube, and then the first optical fiber transmits the light to the photodiode PD2 and the photodiode PD3.

[0012] Further, the photodiode PD1 is used to eliminate the change in light intensity; the photodiode PD2 is used to eliminate the bubble interference;

[0013] Because tiny bubbles will continuously appear in normal water samples, the photodiode PD2 is used to eliminate the interference of bubbles.

[0014] Further, after the pump set is started, the water sample is injected into the metal tube, the light-emitting diode LED1 is lit, the photodiode PD1 measures the signal a1, the photodiode PD2 measures the signal b1, and the photodiode PD3 measures the signal c1; the light-emitting diode LED1 is turned off, the light-emitting diode LED2 is turned on, the photodiode PD1 measures the signal a2, the photodiode PD2 measures the signal b2, and the photodiode PD3 measures the signal c2.

[0015] Further, after the pump group starts, the water sample-reagent mixture is injected into the metal tube, the light-emitting diode LED1 is lit, and the signals measured by the photodiodes PD1, PD2, and PD3 are a3, b3, and c3 respectively; the light-emitting diode LED1 is turned off, the light-emitting diode LED2 is turned on, and the signals measured by the photodiodes PD1, PD2, and PD3 are a4, b4, and c4 respectively.

[0016] Further, the test system calculates the silicon element content according to a preset formula, and the calculation formula is as follows:

[0017] ABS 650 =LOG 10 (b2 / b4 * a4 / a2);

[0018] ABS 850 =LOG 10 (c1 / c3 * α3 / a1);

[0019] ABS = ABS 850 +K * ABS 650 ;

[0020] Si = SLOPE * ABS + INTERCEPT;

[0021] Among them, a2 is the light intensity of LED2 detected when measuring the water sample; a4 is the light intensity of the light-emitting diode LED2 detected when measuring the water sample-reagent mixture; b2 is the light intensity of the light-emitting diode LED2 passing through the metal tube when measuring the water sample; b4 is the light intensity of the light-emitting diode LED2 passing through the metal tube when measuring the water sample-reagent mixture; a4 / a2 represents the change in the light intensity of the light-emitting diode LED2 during the two measurements; LOG(b2 / b4) represents the absorbance of the water sample-reagent mixture relative to the water sample;

[0022] Among them, a1 is the light intensity of the light-emitting diode LED1 detected when measuring the water sample; a4 is the light intensity of the light-emitting diode LED1 detected when measuring the water sample-reagent mixture; b2 is the light intensity of the light-emitting diode LED1 passing through the metal tube when measuring the water sample; b4 is the light intensity of the light-emitting diode LED1 passing through the metal tube when measuring the water sample-reagent mixture; a3 / a1 represents the change in the light intensity of the light-emitting diode LED2 during the two measurements; LOG(c1 / c3) represents the absorbance of the water sample-reagent mixture relative to the water sample; Si represents the silicon element content;

[0023] Due to the drift of LED light, when measuring ultra-low absorbance, the absorbance calculation formula needs to be changed from ABS = LOG(water sample / mixed solution) to ABS = LOG(water sample / mixed solution * light intensity change); according to the absorption spectrum, Si (silicon) in the water after the reaction of the water sample and the reagent has a relatively high absorption rate at 850 nm, while the absorption rate at 650 nm is relatively low. Below 10 ppb of Si (silicon) content, there is no absorbance contribution at 650 nm, and the absorbance at 650 nm only comes from the background absorption of the reagent. After the reagent is determined, its background absorption is a fixed value.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] 1. The metal tube cuvette used in the present invention simultaneously realizes a long optical path and low reagent consumption;

[0026] 2. The dual-lamp three-PD optical configuration scheme adopted in the present invention, combined with a unique compensation formula, effectively eliminates bubble interference and electrical drift. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the system structure of a novel ultra-low silicon content testing system of the present invention;

[0028] Figure 2 It is a cross-sectional view of the cuvette of a novel ultra-low silicon content testing system of the present invention;

[0029] Figure 3 It is a schematic diagram of the optical fiber structure of a novel ultra-low silicon content testing system of the present invention;

[0030] Figure 4 It is a schematic diagram of the working process of a novel ultra-low silicon content testing system of the present invention;

[0031] Figure 5 It is a schematic diagram of a traditional colorimetric dish of a novel ultra-low silicon content testing system of the present invention.

[0032] In the figure: 1. Control unit; 2. Power supply; 3. Testing unit; 4. Pump group; 5. Cuvette; 6. Mixed solution pool; 7. Overflow pool; 8. Hydraulic valve; a. Outlet of the first peek pipeline; b. Inlet of the second peek pipeline; c. Metal tube; d. First optical fiber; e. Second optical fiber. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0033] Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0034] Example: As Figures 1 - 5As shown in the figure, the present invention provides a technical solution, a novel ultra-low silicon content testing system, and the testing system includes: a control unit 1, a power supply 2, a testing unit 3, a pump set 4, a colorimetric cell 5, a mixing cell 6, an overflow cell 7, and a pressure relief valve 8;

[0035] Referring to Figure 1 , the testing unit 3 is connected to the colorimetric cell 5; the pump set 4 is respectively connected to the mixing cell 6, the overflow cell 7, and the pressure relief valve 8; the colorimetric cell 5 is connected to the mixing cell 6; the overflow cell 7 is connected to the pressure relief valve 8;

[0036] Among them, the pump set 4 includes three standard peristaltic pumps; among them, the main hose of the first standard peristaltic pump is connected to the first end of the mixing cell 6, and the auxiliary hose of the first standard peristaltic pump is connected to the pressure relief valve 8; the main hose of the second standard peristaltic pump is connected to the second port of the mixing cell 6, and the auxiliary hose of the second standard peristaltic pump is connected to the pressure relief valve 8; the main hose of the third standard peristaltic pump is connected to the third end of the mixing cell 6, and the auxiliary hose of the third standard peristaltic pump is connected to the overflow cell 7;

[0037] Referring to Figure 2 , among them, the colorimetric cell 5 includes a first PEEK pipeline, a second PEEK pipeline, a first optical fiber, a second optical fiber, and a metal tube; among them, the first end of the first optical fiber is connected to the first end of the first PEEK pipeline; the first end of the second optical fiber is connected to the first end of the second PEEK pipeline; the metal tube connects the second ends of the first PEEK pipeline and the second PEEK pipeline;

[0038] In an embodiment of the present invention, the outer diameter of the metal tube is 3 mm, the inner diameter is 1 mm, and the length is 50 mm;

[0039] Referring to Figure 3 , among them, the testing unit 3 includes a photodiode PD1, a photodiode PD2, a photodiode PD3, a light-emitting diode LED1, and a light-emitting diode LED2; among them, the photodiode PD2 and the photodiode PD3 are connected to the second end of the first optical fiber; the photodiode PD3, the light-emitting diode LED1, and the light-emitting diode LED2 are connected to the second end of the second optical fiber;

[0040] In an embodiment of the present invention, the emission wavelength of the light-emitting diode LED1 is 850 nm, and the emission wavelength of the light-emitting diode LED2 is 650 nm; the photodiodes PD1, PD2, and PD3 are all photodiodes of the same manufacturer and the same batch, and there is no filter in front of the photodiode PD1, a 650 nm (±5 nm) band-pass filter is installed in front of the photodiode PD2, and an 850 (±5 nm) band-pass filter is installed in front of the photodiode PD3;

[0041] Among them, the photodiode PD1 is used to eliminate the change in light intensity; the photodiode PD2 is used to eliminate the bubble interference;

[0042] Refer to Figure 4 , where, after the pump group 4 is started, the water sample is injected into the metal tube, the light-emitting diode LED1 is lit, the photodiode PD1 measures the signal a1, the photodiode PD2 measures the signal b1, and the photodiode PD3 measures the signal c1; the light-emitting diode LED1 is turned off, the light-emitting diode LED2 is turned on, the photodiode PD1 measures the signal a2, the photodiode PD2 measures the signal b2, and the photodiode PD3 measures the signal c2;

[0043] Refer to Figure 4 , where, after the pump group 4 is started, the water sample-reagent mixture is injected into the metal tube, the light-emitting diode LED1 is lit, and the signals measured by the photodiode PD1, the photodiode PD2, and the photodiode PD3 are a3, b3, and c3 respectively; the light-emitting diode LED1 is turned off, the light-emitting diode LED2 is turned on, and the signals measured by the photodiode PD1, the photodiode PD2, and the photodiode PD3 are a4, b4, and c4 respectively;

[0044] In the embodiment of the present invention, the reagent is added according to the volume ratio of the cuvette (such as Figure 2 ), the reagent addition amount is calculated as V = L * PI * R * R = 5 * 3.1415 * 0.05 * 0.05 = 0.078 ml; the traditional cuvette is as Figure 5 shown, with a length, width, and height of 5 cm * 1 cm * 1 cm. Therefore, the reagent addition amount of the traditional cuvette is V = L * W * H = 5 * 1 * 1 = 5 ml. So, the reagent addition amount of the present invention is significantly lower than that of the traditional cuvette;

[0045] Among them, the test system calculates the silicon element content according to a preset formula, and the calculation formula is as follows:

[0046] ABS 650 = LOG 10 (b2 / b4 * a4 / α2);

[0047] ABS 850 = LOG 10 (c1 / c3 * α3 / a1);

[0048] ABS = ABS 850 + K * ABS 650 ;

[0049] Si = SLOPE * ABS + INTERCEPT;

[0050] Among them, a2 is the light intensity of LED2 detected when measuring the water sample; a4 is the light intensity of the light-emitting diode LED2 detected when measuring the water sample-reagent mixture; b2 is the light intensity of the light-emitting diode LED2 passing through the metal tube when measuring the water sample; b4 is the light intensity of the light-emitting diode LED2 passing through the metal tube when measuring the water sample-reagent mixture; a4 / a2 represents the change in the light intensity of the light-emitting diode LED2 during the two measurements; LOG(b2 / b4) represents the absorbance of the water sample-reagent mixture relative to the water sample;

[0051] Among them, a1 is the light intensity of the light-emitting diode LED1 detected when measuring the water sample; a4 is the light intensity of the light-emitting diode LED1 detected when measuring the water sample-reagent mixture; b2 is the light intensity of the light-emitting diode LED1 passing through the metal tube when measuring the water sample; b4 is the light intensity of the light-emitting diode LED1 passing through the metal tube when measuring the water sample-reagent mixture; a3 / a1 represents the change in the light intensity of the light-emitting diode LED2 during the two measurements; LOG(c1 / c3) represents the absorbance of the water sample-reagent mixture relative to the water sample; Si represents the silicon element content.

[0052] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A novel ultra-low silicon content testing system, characterized in that: The described test system includes: a control unit (1), a power supply (2), a test unit (3), a pump set (4), a colorimetric cell (5), a mixing cell (6), an overflow cell (7), and a pressure relief valve (8); The test unit (3) is connected to the colorimetric cell (5); the pump set (4) is respectively connected to the mixing cell (6), the overflow cell (7), and the pressure relief valve (8); the colorimetric cell (5) is connected to the mixing cell (6); the overflow cell (7) is connected to the pressure relief valve (8).

2. The novel ultra-low silicon content testing system according to claim 1, wherein: The pump set (4) includes three standard peristaltic pumps; among them, the main hose of the first standard peristaltic pump is connected to the first end of the mixing cell (6), and the auxiliary hose of the first standard peristaltic pump is connected to the pressure relief valve (8); the main hose of the second standard peristaltic pump is connected to the second port of the mixing cell (6), and the auxiliary hose of the second standard peristaltic pump is connected to the pressure relief valve (8); the main hose of the third standard peristaltic pump is connected to the third end of the mixing cell (6), and the auxiliary hose of the third standard peristaltic pump is connected to the overflow cell (7).

3. A novel ultra-low silicon content testing system according to claim 1, characterized in that: The colorimetric cell (5) includes a first PEEK pipeline, a second PEEK pipeline, a first optical fiber, a second optical fiber, and a metal pipe; among them, the first end of the first optical fiber is connected to the first end of the first PEEK pipeline; the first end of the second optical fiber is connected to the first end of the second PEEK pipeline; the metal pipe connects the second ends of the first PEEK pipeline and the second PEEK pipeline.

4. A novel ultra-low silicon content testing system according to claim 3, characterized in that: The test unit (3) includes a photodiode PD1, a photodiode PD2, a photodiode PD3, a light-emitting diode LED1, and a light-emitting diode LED2; among them, the photodiode PD2 and the photodiode PD3 are connected to the second end of the first optical fiber; the photodiode PD3, the light-emitting diode LED1, and the light-emitting diode LED2 are connected to the second end of the second optical fiber.

5. The novel ultra-low silicon content testing system according to claim 4, characterized in that: The photodiode PD1 is used to eliminate the change in light intensity; the photodiode PD2 is used to eliminate bubble interference.

6. A novel ultra-low silicon content testing system according to claim 1, characterized in that: After the pump set (4) is started, water samples are injected into the metal pipe, the light-emitting diode LED1 is lit, the photodiode PD1 measures signal a1, the photodiode PD2 measures signal b1, and the photodiode PD3 measures signal c1; the light-emitting diode LED1 is turned off, the light-emitting diode LED2 is turned on, the photodiode PD1 measures signal a2, the photodiode PD2 measures signal b2, and the photodiode PD3 measures signal c2.

7. A novel ultra-low silicon content testing system according to claim 1, characterized in that: After the pump set (4) is started, a water sample-reagent mixture is injected into the metal pipe, the light-emitting diode LED1 is lit, and the signals measured by the photodiode PD1, the photodiode PD2, and the photodiode PD3 are a3, b3, and c3 respectively; the light-emitting diode LED1 is turned off, the light-emitting diode LED2 is turned on, and the signals measured by the photodiode PD1, the photodiode PD2, and the photodiode PD3 are a4, b4, and c4 respectively.

8. A novel ultra-low silicon content testing system according to claim 1, characterized in that: The test system calculates the silicon element content according to a preset formula, and the calculation formula is as follows: ABS 650 = LOG 10 (b2 / b4 * a4 / α2); ABS 850 =LOG 10 (c1 / c3*α3 / a1); ABS = ABS 850 + K * ABS 650 ; Si = SLOPE * ABS + NTERCEPT; Among them, a2 is the light intensity of LED2 detected when measuring the water sample; a4 is the light intensity of the light-emitting diode LED2 detected when measuring the water sample-reagent mixture; b2 is the light intensity of the light-emitting diode LED2 passing through the metal tube when measuring the water sample; b4 is the light intensity of the light-emitting diode LED2 passing through the metal tube when measuring the water sample-reagent mixture; a4 / a2 represents the change in the light intensity of the light-emitting diode LED2 during the two measurements; LOG(b2 / b4) represents the absorbance of the water sample-reagent mixture relative to the water sample; Among them, a1 is the light intensity of the light-emitting diode LED1 detected when measuring the water sample; a4 is the light intensity of the light-emitting diode LED1 detected when measuring the water sample-reagent mixture; b2 is the light intensity of the light-emitting diode LED1 passing through the metal tube when measuring the water sample; b4 is the light intensity of the light-emitting diode LED1 passing through the metal tube when measuring the water sample-reagent mixture; a3 / a1 represents the change in the light intensity of the light-emitting diode LED2 during the two measurements; LOG(c1 / c3) represents the absorbance of the water sample-reagent mixed solution relative to the water sample; Si represents the silicon element content.

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