System for testing turbidity in water by laser method

Abstract

The invention discloses a system for testing turbidity in water by a laser method, which comprises a measuring cell, a laser source, an image collector and a computer, the measuring cell is made of a transparent material, a liquid inlet pipe and a liquid discharge pipe are arranged on the measuring cell, and a flow meter is arranged on the liquid discharge pipe and is used for calculating the water flow volume V in the measuring cell in unit time; the laser source and the image collector are oppositely arranged on the two sides of the measuring cell, the laser source is used for emitting a laser beam towards the measuring cell, and the image collector is used for collecting a particle image in test water in the measuring cell; the computer is in signal connection with the image so as to obtain the particle count m and the particle equivalent volume v in the water in unit time, the density rho of the tested water is defined, and the turbidity is equal to mrho v / V. According to the system for testing the turbidity in the water by the laser method, the testing process is simplified, the complexity and the complexity of preparing a standard solution are reduced, the health risk is effectively reduced, and the system has relatively high testing accuracy.

Description

Technical Field

[0001] The invention relates to the technical field of turbidity testing, and in particular to a laser method turbidity testing system in water. Background Art

[0002] In the existing water turbidity testing technology, spectrophotometers or turbidity meters are generally used for measurement based on the scattered light principle, relying on the configuration of standard solutions (such as formazin or hydrazine sulfate and hexamethylenetetrahydrazine polymerization). However, this traditional method has many disadvantages, including complex and cumbersome standard solution configuration, strong carcinogenic risk, and test accuracy depends on the standard solution, resulting in the difference between the actual solution and the standard solution affecting the test accuracy. Summary of the invention

[0003] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0004] To this end, an embodiment of the present invention provides a laser-based water turbidity testing system.

[0005] The laser method water turbidity testing system of the embodiment of the present invention includes a measuring cell, a laser source, an image collector and a computer. The measuring cell is made of a transparent material. The measuring cell is provided with an inlet pipe and a discharge pipe. The inlet pipe is used to transport test water into the measuring cell, and the discharge pipe is used to discharge the test water after measurement. The discharge pipe is provided with a flow meter for calculating the water flow volume V per unit time in the measuring cell. The laser source and the image collector are arranged on two sides of the measuring cell relatively to each other. The laser source is used to emit a laser beam toward the measuring cell, and the image collector is used to collect images of particles in the test water in the measuring cell. The computer is connected to the image signal and is used to process the data collected by the image collector to obtain the particle count m and the particle equivalent volume v in the water per unit time. The density of the test water is defined as ρ, where turbidity = mρv / V.

[0006] In some embodiments, the laser source includes a laser emitter and a collimating lens, the laser emitter is used to emit multiple laser beams toward the collimating lens, and the multiple laser beams are refracted by the collimating lens to form multiple parallel light beams that are vertically irradiated on the side wall of the measuring cell.

[0007] In some embodiments, the laser water turbidity testing system of the embodiment of the present invention also includes a stirring tank, which has a liquid inlet and a liquid outlet. The liquid inlet is used for test water to enter the stirring tank for stirring, and the liquid outlet is connected to the liquid inlet pipe so that the stirred test water can enter the measuring tank.

[0008] The laser water turbidity testing system of the embodiment of the present invention also includes a stirring shaft, a stirring impeller and a motor. The stirring shaft is rotatably arranged on the top wall of the stirring pool and one end extends into the stirring pool. The motor is arranged outside the stirring pool and connected to the stirring shaft. The stirring impeller is arranged in the stirring pool and connected to the stirring shaft.

[0009] The laser method water turbidity testing system of the embodiment of the present invention further comprises a water pump, the water inlet of the water pump is used for the sample liquid to enter, and the water outlet of the water pump is connected to the liquid inlet of the stirring tank.

[0010] In some embodiments, a water pipe is provided on the water inlet of the water pump, the water pipe is used to communicate with the test water, and a first opening and closing valve is provided on the water pipe.

[0011] In some embodiments, a cleaning pipe is provided on the water pipe, and the cleaning pipe is located between the first on-off valve and the water pump. The cleaning pipe is used to transport cleaning liquid into the first water pipe to clean the pipeline of the laser water turbidity testing system.

[0012] In some embodiments, the laser water turbidity testing system of the embodiment of the present invention further includes a cleaning bottle, in which a cleaning liquid is provided, and one end of the cleaning tube extends into the cleaning bottle.

[0013] In some embodiments, a second opening and closing valve is provided on the cleaning pipe.

[0014] In some embodiments, the measuring cell is made of optical glass.

[0015] The laser method water turbidity test system of the embodiment of the present invention does not need to rely on standard solutions for testing, thereby simplifying the test process and reducing the complexity and cumbersomeness of configuring standard solutions. In traditional turbidity test methods, the standard solutions used, such as formazine, have a strong carcinogenic risk. The present invention adopts a laser method and does not need to use such harmful substances, effectively reducing health risks. Since the present invention directly measures the image of particles in water, it is not affected by the difference between the standard solution and the actual solution, and therefore has a higher test accuracy. The present invention can realize real-time monitoring of turbidity changes in water, which provides convenience for water quality control and pollution monitoring. The system has a simple structure and a wide range of applications, and can be applied to water quality detection fields in industries such as environmental monitoring, industrial production, and medical treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of a laser water turbidity testing system according to an embodiment of the present invention.

[0017] Reference numerals:

[0018] 100. Laser method for testing turbidity in water; 1. Measuring cell; 2. Liquid inlet pipe; 3. Liquid discharge pipe; 4. Laser source; 401. Laser transmitter; 402. Collimating lens; 5. Image acquisition device; 6. Computer; 7. Stirring cell; 701. Liquid inlet; 702. Liquid outlet; 8. Stirring shaft; 9. Stirring impeller; 10. Motor; 11. Water pump; 12. Water pipe; 13. First on-off valve; 14. Cleaning pipe; 15. Cleaning bottle; 16. Second on-off valve. DETAILED DESCRIPTION

[0019] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0020] like Figure 1 As shown, the laser method water turbidity test system 100 of the embodiment of the present invention includes a measuring pool 1, a laser source 4, an image acquisition device 5 and a computer 6. The measuring pool 1 is made of a transparent material, and is provided with a liquid inlet pipe 2 and a liquid discharge pipe 3. The liquid inlet pipe 2 is used to transport the test water into the measuring pool 1, and the liquid discharge pipe 3 is used to discharge the test water after measurement. The liquid discharge pipe 3 is provided with a flow meter for calculating the water flow volume V per unit time in the measuring pool 1.

[0021] The laser source 4 and the image collector 5 are arranged on both sides of the measuring pool 1. The laser source 4 is used to emit a laser beam toward the measuring pool 1, and the image collector 5 is used to collect images of particles in the test water in the measuring pool 1. The computer 6 is connected to the image signal and is used to process the data collected by the image collector 5 to obtain the particle count m and the particle equivalent volume v in the water per unit time. The density of the test water is defined as ρ, where turbidity = mρv / V.

[0022] When the laser method water turbidity test system 100 of the embodiment of the present invention is used, the measuring pool 1 is made of transparent material to ensure that the laser beam can pass smoothly. At the same time, a liquid inlet pipe 2 and a liquid outlet pipe 3 are provided to transport the test water into the measuring pool 1 and discharge the test water after measurement. The laser source 4 emits a laser beam, and the laser beam passes through the test water in the measuring pool 1. When the laser beam encounters particles in the water, a scattering phenomenon will occur. The intensity and direction of the scattered light are related to the size, shape and number of the particles. The image collector 5 is located on the other side of the measuring pool 1, and is used to collect images of the particles in the test water in real time. These images contain the number, size and distribution information of the particles. The computer 6 is connected to the image collector 5, receives and processes the collected image data, and the computer 6 analyzes the image to calculate the particle count m and the particle equivalent volume v per unit time. According to the formula turbidity = mρv / V, the computer 6 calculates the turbidity of the test water. Among them, ρ is the density of the test water, and V is the volume of water flowing per unit time in the measuring pool 1.

[0023] The laser method water turbidity test system 100 of the embodiment of the present invention does not need to rely on standard solutions for testing, thereby simplifying the test process and reducing the complexity and cumbersomeness of configuring standard solutions. In traditional turbidity test methods, the standard solutions used, such as formazine, have a strong carcinogenic risk. The present invention adopts a laser method and does not need to use such harmful substances, effectively reducing health risks. Since the present invention directly measures the image of particles in water, it is not affected by the difference between the standard solution and the actual solution, and therefore has a higher test accuracy. The present invention can realize real-time monitoring of turbidity changes in water, which provides convenience for water quality control and pollution monitoring. The system has a simple structure and a wide range of applications, and can be applied to water quality detection fields in industries such as environmental monitoring, industrial production, and medical treatment.

[0024] In some embodiments, the laser source 4 includes a laser emitter 401 and a collimating lens 402 . The laser emitter 401 is used to emit multiple laser beams toward the collimating lens 402 . The multiple laser beams are refracted by the collimating lens 402 to form multiple parallel light beams that are vertically irradiated on the side wall of the measuring cell 1 .

[0025] The laser emitter 401 is used to emit multiple laser beams, which start from the emitter and propagate toward the collimating lens 402. The collimating lens 402 is located on the path of the laser emitter 401, and is used to refract the multiple laser beams and form multiple parallel light beams. The design of the collimating lens 402 ensures that the laser beams remain parallel after passing through the lens. The multiple parallel light beams refracted by the collimating lens 402 are vertically irradiated on the side wall of the measuring cell 1. This design enables the laser beam to produce a uniform scattering effect in the water, which is conducive to the image collector 5 to capture more accurate particle images, improve the uniformity of the laser beam, thereby making the measurement of scattered light more accurate, enhancing the stability and repeatability of the measurement system, and reducing the measurement error caused by the non-parallel laser beam.

[0026] In some embodiments, the laser water turbidity testing system 100 of the embodiment of the present invention also includes a stirring tank 7, the stirring tank 7 has a liquid inlet 701 and a liquid outlet 702, the liquid inlet 701 is used for the test water to enter the stirring tank 7 for stirring, and the liquid outlet 702 is connected to the liquid inlet pipe 2 so that the stirred test water enters the measuring tank 1.

[0027] When the test water enters the stirring tank 7 through the liquid inlet 701, the stirring device starts to work to ensure that the particles in the water are evenly mixed. The stirred test water flows out through the liquid outlet 702 and flows into the measuring tank 1. Through stirring, the particles in the test water are more evenly distributed, thereby improving the accuracy of the measurement results. The stirring process reduces the measurement error caused by local aggregation of particles. The stirring tank 7 ensures the consistency of each test condition and enhances the repeatability of the test. This design can be applied to different types of test water, especially those samples with uneven particle distribution.

[0028] In some embodiments, the laser method water turbidity testing system 100 of the embodiment of the present invention further includes a stirring shaft 8, a stirring impeller 9 and a motor 10. The stirring shaft 8 is rotatably arranged on the top wall of the stirring tank 7 and one end thereof extends into the stirring tank 7, the motor 10 is arranged outside the stirring tank 7 and connected to the stirring shaft 8, and the stirring impeller 9 is arranged inside the stirring tank 7 and connected to the stirring shaft 8.

[0029] After the motor 10 is started, the stirring shaft 8 rotates to drive the stirring impeller 9 to rotate. When the stirring impeller 9 rotates in the stirring tank 7, the water is stirred, thereby achieving uniform distribution of the particles. Through the combination of the stirring shaft 8, the stirring impeller 9 and the motor 10, the system can quickly achieve uniform distribution of particles in the test water. Uniformly distributed particles contribute to laser scattering measurement, thereby improving the accuracy of turbidity testing. The design of the stirring device ensures that the stirring conditions are consistent for each test, thereby enhancing the repeatability and reliability of the test results. The stirring device is located at the top of the stirring tank 7 for easy maintenance and operation.

[0030] In some embodiments, the laser water turbidity testing system 100 of the embodiment of the present invention further includes a water pump 11 , the water inlet of the water pump 11 is used for sample liquid to enter, and the water outlet of the water pump 11 is connected to the liquid inlet 701 of the stirring tank 7 .

[0031] When the system is started, the water pump 11 sucks the sample liquid through the water inlet, and the sample liquid flows into the liquid inlet 701 of the stirring tank 7 through the water outlet under the pressure of the water pump 11. In the stirring tank 7, the stirring device (such as the aforementioned stirring shaft 8, stirring impeller 9 and motor 10) stirs the sample liquid to ensure uniform distribution of particles. The stirred sample liquid flows into the measuring tank 1 through the liquid outlet 702 of the stirring tank 7 for use in the laser turbidity test.

[0032] The flow rate of the water pump 11 can be adjusted to control the flow rate of the sample liquid entering the stirring tank 7, ensuring that the liquid in the stirring tank 7 is evenly mixed. By adjusting the flow rate and pressure of the water pump 11, the stirring effect can be optimized and the uniform distribution of the particles can be improved. The addition of the water pump 11 automates the transportation and stirring process of the sample liquid, reduces manual operation, and improves the test efficiency. The water pump 11 can adjust the flow rate according to different test requirements and is suitable for sample liquids with different viscosities and fluidities.

[0033] In some embodiments, a water pipe 12 is provided on the water inlet of the water pump 11 . The water pipe 12 is used to communicate with the test water. A first opening and closing valve 13 is provided on the water pipe 12 .

[0034] The connection between the water pipe 12 and the test water can accurately control the flow and pressure of the test water, thereby ensuring the stability and accuracy of the water pressure under the test conditions, which is crucial for conducting a water seal and watertightness test. The setting of the first on-off valve 13 allows the operator to open or close the water flow according to the test requirements, increases the water flow control during the test process, and improves the controllability of the system. When the water pump 11, the water pipe 12 or other components need to be repaired or replaced, the first on-off valve 13 can easily cut off the water flow, providing convenience for maintenance work.

[0035] When performing a hydraulic pressure test, if an emergency occurs, the first on-off valve 13 can be quickly closed to stop the water flow, thereby ensuring the safety of personnel and equipment. The first on-off valve 13 can adjust the opening as needed to match the working conditions of the water pump 11, thereby improving the working efficiency of the water pump 11.

[0036] In some embodiments, a cleaning pipe 14 is provided on the water pipe 12 . The cleaning pipe 14 is located between the first on-off valve 13 and the water pump 11 . The cleaning pipe 14 is used to transport cleaning liquid into the first water pipe 12 to clean the pipeline of the laser water turbidity testing system 100 .

[0037] The design of the cleaning pipe 14 makes it easy to inject cleaning fluid into the water pipe 12, which is used to clean the system pipeline before the test, thereby maintaining the cleanliness of the system. It can ensure that there are no suspended matter and sediment in the pipeline that affect the accuracy of the laser method water turbidity test, and ensure that the test results are true and reliable. The cleaning fluid can remove corrosive substances and sediments in the pipeline, reduce corrosion to the pipeline material, and thus extend the service life of the pipeline and related equipment.

[0038] In some embodiments, the laser water turbidity testing system 100 of the embodiment of the present invention further includes a cleaning bottle 15 , in which cleaning liquid is provided, and one end of the cleaning tube 14 extends into the cleaning bottle 15 .

[0039] The cleaning bottle 15 is a container for storing cleaning liquid, which helps to centrally manage and use the cleaning liquid, which is convenient and quick. The design of the cleaning bottle 15 makes it easy to replace the cleaning liquid. You only need to replace the cleaning liquid in the bottle without complicated operating steps. Since the cleaning liquid is stored in the cleaning bottle 15 and isolated from the outside world, it can reduce the contamination of the cleaning liquid by external pollutants and maintain the purity of the cleaning liquid. The cleaning tube 14 extends into the cleaning bottle 15, and the flow rate of the cleaning liquid can be adjusted by controlling the opening size of the cleaning tube 14 or using a control valve to ensure the effectiveness of the cleaning process. The cleaning bottle 15 can be integrated with the control unit of the test system to realize the automatic cleaning function and improve the intelligence level of the system. The cleaning tube 14 directly transports the cleaning liquid into the pipeline, which can quickly and evenly clean the entire test system and improve the cleaning efficiency.

[0040] In some embodiments, a second on-off valve 16 is disposed on the cleaning pipe 14 .

[0041] The setting of the second opening and closing valve 16 increases the control over the flow of the cleaning liquid, and the flow of the cleaning liquid can be opened or closed when necessary, thereby improving the controllability of the cleaning process. When performing the cleaning operation, if an emergency occurs, the second opening and closing valve 16 can be quickly closed to immediately stop the flow of the cleaning liquid to prevent accidents. By controlling the second opening and closing valve 16, the flow rate and usage of the cleaning liquid can be adjusted according to actual needs, unnecessary waste can be avoided, and the purpose of saving resources can be achieved. When the cleaning pipe 14 needs maintenance or replacement, the second opening and closing valve 16 can be closed to cut off the supply of the cleaning liquid, which is convenient for maintenance operations. The second opening and closing valve 16 can be used to control the timing and duration of the flow of the cleaning liquid, which helps to optimize the cleaning process and improve the cleaning efficiency.

[0042] In some embodiments, the measuring cell 1 is made of optical glass.

[0043] Optical glass has extremely high transparency, which can ensure that light can pass through unimpeded during the measurement process, thereby improving the measurement precision and accuracy. This is particularly important for experiments that require accurate measurement of optical properties. Optical glass usually has good chemical stability and thermal stability, can resist chemical corrosion and temperature changes, and ensure long-term reliability. Optical glass is required to have a high degree of uniformity during the manufacturing process, so as to avoid the influence of uneven internal stress or inconsistent optical properties on the measurement results. Optical glass can be processed with high precision, such as precision polishing and precision cutting, to ensure that the size and shape of the measuring cell 1 meet the requirements of accurate measurement. Optical glass has good mechanical strength and wear resistance, can withstand certain mechanical stress, and is not easy to be damaged, thereby ensuring the stability and durability of the measuring equipment. The surface of optical glass is smooth, not easy to adhere to dirt, and is relatively easy to clean, which helps to keep the measurement environment clean and the accuracy of the measurement results. Optical glass has a wide transmittance range for light of different wavelengths and is suitable for a variety of optical measurement needs, such as ultraviolet to near-infrared band measurements. The measuring cell 1 made of optical glass can reduce measurement interference caused by the characteristics of the material itself, such as light scattering, refractive index changes, etc.

[0044] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0045] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0046] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0047] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0048] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0049] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A laser method water turbidity test system, characterized in that: include: A measuring pool (1), wherein the measuring pool (1) is made of a transparent material, and is provided with a liquid inlet pipe (2) and a liquid discharge pipe (3), wherein the liquid inlet pipe (2) is used to transport test water into the measuring pool (1), and the liquid discharge pipe (3) is used to discharge the test water after measurement, and the liquid discharge pipe (3) is provided with a flow meter for calculating the water flow volume V per unit time in the measuring pool (1); A laser source (4) and an image collector (5), wherein the laser source (4) and the image collector (5) are arranged on two sides of the measuring pool (1) opposite to each other, the laser source (4) is used to emit a laser beam toward the measuring pool (1), and the image collector (5) is used to collect images of particles in the test water in the measuring pool (1); A computer (6) is connected to the image signal and is used to process the data collected by the image collector (5) to obtain the particle count m and particle equivalent volume v in the water per unit time, and the density of the test water is defined as ρ, where turbidity = mρv / V.

2. The laser method water turbidity testing system according to claim 1, characterized in that: The laser source (4) comprises a laser emitter (401) and a collimating lens (402), wherein the laser emitter (401) is used to emit multiple laser beams toward the collimating lens (402), and the multiple laser beams are refracted by the collimating lens (402) to form multiple beams of parallel light that are vertically irradiated on the side wall of the measuring cell (1).

3. The laser method water turbidity testing system according to claim 1, characterized in that: The invention also comprises a stirring tank (7), wherein the stirring tank (7) has a liquid inlet (701) and a liquid outlet (702), wherein the liquid inlet (701) is used for the test water to enter the stirring tank (7) for stirring, and the liquid outlet (702) is connected to the liquid inlet pipe (2) so that the stirred test water can enter the measuring tank (1).

4. The laser method water turbidity testing system according to claim 3, characterized in that: The stirring device further comprises a stirring shaft (8), a stirring impeller (9) and a motor (10); the stirring shaft (8) is rotatably arranged on the top wall of the stirring pool (7) and one end of the stirring shaft extends into the stirring pool (7); the motor (10) is arranged outside the stirring pool (7) and connected to the stirring shaft (8); the stirring impeller (9) is arranged inside the stirring pool (7) and connected to the stirring shaft (8).

5. The laser method water turbidity testing system according to claim 4, characterized in that: It also comprises a water pump (11), wherein the water inlet of the water pump (11) is used for the sample liquid to enter, and the water outlet of the water pump (11) is connected to the liquid inlet (701) of the stirring tank (7).

6. The laser method water turbidity testing system according to claim 5, characterized in that: A water delivery pipe (12) is provided on the water inlet of the water pump (11), and the water delivery pipe (12) is used to communicate with the test water. A first opening and closing valve (13) is provided on the water delivery pipe (12).

7. The laser method water turbidity testing system according to claim 6, characterized in that: The water pipe (12) is provided with a cleaning pipe (14), the cleaning pipe (14) being located between the first on-off valve (13) and the water pump (11), and the cleaning pipe (14) being used to transport cleaning liquid into the first water pipe (12) to clean the pipeline of the laser method water turbidity test system.

8. The laser method water turbidity testing system according to claim 7, characterized in that: It also comprises a cleaning bottle (15), in which cleaning liquid is arranged, and one end of the cleaning tube (14) extends into the cleaning bottle (15).

9. The laser method water turbidity testing system according to claim 8, characterized in that: The cleaning pipe (14) is provided with a second opening and closing valve (16).

10. The laser method water turbidity testing system according to claim 1, characterized in that: The measuring cell (1) is made of optical glass.

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