Turbidimeter

Abstract

The turbidimeter is characterized in that an optical system of the turbidimeter comprises a light source I, a collimating lens I, a beam splitter prism, a converging lens, a 90-degree receiver, a tested sample, a plane mirror, a forward scattering receiver, a forward transmission receiver, a light source II and a collimating lens II, the turbidimeter can meet the measurement requirements of the USEPA180.1 turbidity standard and the ISO 7027 turbidity standard at the same time, and has a wider application range; meanwhile, a full LED lamp source is adopted, so that the instrument is small in heat emission, long in service life, free of preheating, high in measurement speed and higher in stability and repeatability.

Description

Technical Field

[0001] The utility model belongs to the technical field of material analysis instruments, and specifically relates to a turbidimeter, which can measure and analyze the turbidity of substances according to two different turbidity standards of USEPA180.1 and ISO7027. Background Art

[0002] A turbidimeter is an instrument for measuring the turbidity of water samples. Its basic principle is that when light passes through a sample bottle containing a suspended sample, the ratio of the 90° scattered light signal generated to the sum of the forward transmitted light and the forward scattered light signal changes with the turbidity. Currently, turbidimeters are widely used in power plants, pure water plants, tap water plants, domestic sewage treatment plants, beverage plants, petrochemical industry, food departments, environmental protection departments, industrial water, wine-making industry, pharmaceutical industry, epidemic prevention departments, hospitals and other departments.

[0003] There are two currently popular turbidity measurement standards: one is the USEPA180.1 turbidity standard promulgated by the US Environmental Protection Agency in 1992, which uses a halogen tungsten lamp with a peak wavelength of 400 - 600nm as the light source. Because the scattering effect is more sensitive to blue light in visible light, selecting cyan blue light with a peak wavelength in 400 - 600nm can obtain better sensitivity. However, in this measurement method, the background light and colored organic substances in the measured water sample will have a greater impact on the visible light band, resulting in a significant decrease in measurement accuracy. Therefore, it cannot be used to measure colored water samples. The other is the ISO7027 turbidity standard promulgated by the International Organization for Standardization (ISO) in 1990, which uses an infrared LED with a peak wavelength near 860nm as the light source. Because infrared light can better eliminate the influence of chromaticity in the water sample, but its wavelength is relatively long, resulting in lower sensitivity to small particles.

[0004] According to the two different turbidity standards of USEPA180.1 and ISO7027, the turbidimeters sold on the market can generally be divided into two categories: one is the turbidimeter based on a halogen tungsten lamp, and the other is the turbidimeter based on an infrared LED. Among them, the turbidimeter based on a halogen tungsten lamp has high scattering intensity and good resolution; it is more sensitive to smaller particles, and the lower limit of detected turbidity is low. However, this kind of turbidimeter is greatly affected by chromaticity, cannot be used to measure colored water samples, has poor luminous stability, requires a good dimming and voltage regulating system, and requires a complex optical system. The turbidimeter based on an infrared LED is not affected by chromaticity, can be used to measure colored water samples, has good luminous stability, does not require a complex optical system, but its light intensity is weak and requires more precise signal processing, and it is not sensitive to smaller particles. Summary of the Utility Model

[0005] The object of the present utility model is to address the defect that when measuring the turbidity of substances, two types of turbidimeters based on different standards require different standard turbidimeters for different substances. A turbidimeter is provided that can measure and analyze the turbidity of substances according to two different turbidity standards, namely USEPA180.1 and ISO7027, with accurate measurement accuracy.

[0006] Technical solution

[0007] To achieve the above technical object, the present utility model provides a turbidimeter, characterized in that: the optical system of the turbidimeter includes a first light source, a first collimating lens, a beam splitting prism, a converging lens, a 90° receiver, a measured sample, a plane mirror, a forward scattering receiver, a forward transmission receiver, a second light source and a second collimating lens;

[0008] A first collimating lens is arranged on the light exit path of the first light source. The light emitted by the first light source becomes parallel light after passing through the first collimating lens and is then split into two beams of light by the beam splitting prism on the light exit path of the first collimating lens, namely the main light path and the split light path. The main light path is converged by the converging lens on the light exit path of the beam splitting prism and irradiates the center of the measured sample. The light emitted from the sample is divided into forward transmitted light, forward scattered light and 90° scattered light. The forward transmitted light is reflected by the plane mirror and received by the forward transmission receiver, the forward scattered light is directly received by the forward scattering receiver, and the 90° scattered light is directly received by the 90° receiver;

[0009] A second collimating lens is arranged on the light exit path of the second light source. The light emitted by the second light source becomes parallel light after passing through the second collimating lens. The beam splitting prism is also located on the light exit path of the second collimating lens. The light emitted by the second light source becomes parallel light after passing through the second collimating lens and is also incident on the beam splitting prism on the light exit path of the second collimating lens.

[0010] Further, the first light source is a white light LED light source.

[0011] Further, the second collimating lens is an infrared LED light source.

[0012] Beneficial effects

[0013] The present utility model provides a turbidimeter. The optical system of the turbidimeter includes a first light source, a first collimating lens, a beam splitting prism, a converging lens, a 90° receiver, a measured sample, a plane mirror, a forward scattering receiver, a forward transmission receiver, a second light source and a second collimating lens; this turbidimeter can simultaneously meet the measurements of the USEPA180.1 turbidity standard and the ISO7027 turbidity standard, and has a wider application range; at the same time, an all-LED light source is adopted, the instrument has less heat generation, a long service life, does not require preheating, has a fast measurement speed, and has higher stability and repeatability. Description of the drawings

[0014] Appended Figure 1 is the optical path diagram of the embodiment of the present utility model; Specific embodiments

[0015] The following uses specific specific examples to illustrate the implementation manners of the present utility model. Those skilled in the art can easily understand other advantages and effects of the present utility model from the content disclosed in this specification. The present utility model can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present utility model.

[0016] It should be noted that the structures, ratios, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those skilled in this technology to understand and read, and are not used to limit the limited conditions under which the present utility model can be implemented. Therefore, they do not have technical essential meanings. Any modification of the structure, change of the proportional relationship, or adjustment of the size, without affecting the effects that the present utility model can produce and the purposes that can be achieved, should still fall within the scope that can be covered by the technical content disclosed in the present utility model. At the same time, the terms such as "upper", "lower", "left", "right", "middle", and "one" cited in this specification are only for the convenience of clear narration and are not used to limit the scope under which the present utility model can be implemented. The change or adjustment of their relative relationships, without substantial change in the technical content, should also be regarded as the scope within which the present utility model can be implemented.

[0017] Embodiment

[0018] As shown in the appended Figure 1 As shown, in this embodiment, a turbidimeter is provided, which is characterized in that: the optical system of the turbidimeter includes a first light source 1, a first collimating lens 2, a beam splitting prism 3, a converging lens 4, a 90° receiver 5, a measured sample 6, a plane mirror 7, a forward scattering receiver 8, a forward transmission receiver 9, a second light source 10, and a second collimating lens 11.

[0019] When using the USEPA180.1 turbidity standard, a first collimating lens 2 is arranged on the outgoing optical path of the first light source 1. In this embodiment, the first light source 1 is a white light LED light source. The light emitted by the first light source 1 is turned into parallel light by the beam splitting prism 3 and then divided into two paths of light by the beam splitting prism 3 on the outgoing optical path of the first collimating lens 2, namely the main optical path and the split optical path. The main optical path is converged by the converging lens 4 on the outgoing optical path of the beam splitting prism 3 and irradiates the center of the measured sample 6. The light emitted from the sample is divided into forward transmitted light, forward scattered light, and 90° scattered light. The forward transmitted light is received by the forward transmission receiver 9 after being reflected by the plane mirror 7, the forward scattered light is directly received by the forward scattering receiver 8, and the 90° scattered light is directly received by the 90° receiver 5; the split optical path does not play a role in this embodiment.

[0020] When the ISO7027 turbidity standard is adopted, a collimating lens II 11 is arranged on the outgoing light path of the light source II 10. The light emitted by the light source II 10 is collimated by the collimating lens II 11 into parallel light. The beam splitting prism 3 is also located on the outgoing light path of the collimating lens II 11. The light emitted by the light source II 10 is collimated by the collimating lens II 11 into parallel light and then also hits the beam splitting prism 3 on the outgoing light path of the collimating lens II 11 and is split into two beams of light, namely the main light path and the split light path. The main light path is converged by the converging lens 4 on the outgoing light path of the beam splitting prism 3 and irradiates the center of the measured sample 6. The light emitted from the sample is divided into forward transmitted light, forward scattered light and 90° scattered light. The forward transmitted light is reflected by the plane mirror 7 and received by the forward transmission receiver 9. The forward scattered light is directly received by the forward scattering receiver 8. The 90° scattered light is directly received by the 90° receiver 5. The split light path does not function in this embodiment.

[0021] In this embodiment, the mutual switching between the light source I 1 and the light source II 10 is realized through software control. According to the 90° scattered light signal received by the 90° receiver 5, the forward transmitted light signal received by the forward transmission receiver 9, and the forward scattered light signal received by the forward scattering receiver 8, the turbidity T is calculated by combining the following formula

[0022]

[0023] It should be noted that the above 90° scattered light signal, forward transmitted light signal, and forward scattered light signal all refer to the intensity of the signal.

[0024] In this embodiment, the calibration specimens adopt the formazine standard substances with turbidity of 400 degrees (NTU, FTU) and 4000 degrees (NTU, FTU) promulgated by the National Bureau of Technical Supervision, with a certified uncertainty of ±3% and a valid use period of 1 year.

[0025] The formazine standard solutions with different turbidity values are obtained by accurately diluting the formazine turbidity standard substances in proportion with zero-turbidity water and calibrated volumetric instruments. The calibration specimens are as follows.

[0026]

[0027] Accurately prepare calibration specimens corresponding to the measuring range, calibrate them in ascending order from low to high. After all points are calibrated, a standard line is generated for measuring the turbidity of the sample.

[0028] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as falling within the scope described in this specification.

[0029] The above-described embodiments merely represent several implementation manners of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent of the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the appended claims.

Claims

1. A turbidity meter, characterized in that: The optical system of the turbidity meter comprises a light source 1 (1), a collimating lens 1 (2), a beam splitter prism (3), a converging lens (4), a 90° receiver (5), a sample to be measured (6), a plane reflector (7), a forward scattering receiver (8), a forward transmission receiver (9), a light source 2 (10) and a collimating lens 2 (11); A collimating lens (2) is arranged on the outgoing light path of the light source (1). The light emitted by the light source (1) is converted into parallel light by the collimating lens (2) and then divided into two light paths by a beam splitter (3) on the outgoing light path of the collimating lens (2), namely a main light path and a beam splitter (3). The main light path is converged by a converging lens (4) on the outgoing light path of the beam splitter (3) and irradiated onto the center of the sample (6) to be measured. The light emitted from the sample is divided into forward transmission light, forward scattered light and 90° scattered light. The forward transmission light is reflected by a plane reflector (7) and then received by a forward transmission receiver (9). The forward scattered light is directly received by a forward scattering receiver (8). The 90° scattered light is directly received by a 90° receiver (5). A collimating lens 2 (11) is arranged on the outgoing light path of the second light source (10). The light emitted by the second light source (10) is converted into parallel light by the collimating lens 2 (11). The beam splitter prism (3) is also located on the outgoing light path of the second collimating lens (11). The light emitted by the second light source (10) is converted into parallel light by the second collimating lens (11) and is also incident on the beam splitter prism (3) on the outgoing light path of the second collimating lens (11).

2. A turbidity meter as claimed in claim 1, characterized in that: The light source one (1) is a white light LED light source.

3. A turbidity meter as claimed in claim 1, characterized in that: The collimating lens 2 (11) is an infrared LED light source.

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