Bacterial turbidimeter

Abstract

The bacterial turbidimeter comprises a main circuit board, a driving circuit, a lamp, an analog-to-digital conversion circuit, a first photodiode, a diaphragm, a first convex lens, a second photodiode and a second convex lens, the main circuit board is connected with the lamp through a driving circuit; the first convex lens is parallel to the light path of the lamp, the diaphragm comprises a hole, the hole is formed in the focus position of the first convex lens, and the connecting line of the center position of the hole and the center point of the first convex lens is perpendicular to the light path of the lamp; the first photodiode is arranged on the side, away from the first convex lens, of the diaphragm, and the first photodiode is arranged at the hole; the center point of the second convex lens is located on the light path of the lamp. The second photodiode is arranged at the focus of the second convex lens. The first photodiode and the second photodiode are connected to the main circuit board through an analog-to-digital conversion circuit. The bacterial turbidimeter can improve the detection accuracy. The device can be widely applied to the technical field of instruments and equipment.

Description

Technical Field

[0001] The utility model relates to the technical field of instruments and equipment, in particular to a bacterial turbidity meter. Background Art

[0002] A bacterial turbidimeter is an instrument used to measure the microbial content of water or liquids. It detects the turbidity of the liquid to infer the number of bacteria, algae or other microorganisms in it. Turbidity is the degree to which a liquid becomes cloudy due to the presence of these tiny organisms. Bacterial turbidimeters usually use the principle of light scattering. When light is irradiated onto a liquid sample, microorganisms scatter the light. By measuring the intensity of the scattered light, the turbidity can be determined and the bacterial concentration can be indirectly estimated. This equipment is often used in water quality monitoring, sewage treatment, food and beverage industries, and scientific research.

[0003] In the related technology, the bacterial turbidity meters on the market mainly use the scattering measurement principle, and believe that the relationship curve between the bacterial turbidity measured by the scattering method and the scattered light intensity received by the sensor end is a linear relationship. However, in actual measurements, the light beam from the light source to the scattering area of ​​the bacterial liquid to be measured and the scattered light generated by the area during measurement to the photocell will pass through a certain distance of the bacterial liquid to be measured, and will therefore be attenuated. Therefore, if the bacterial turbidity is directly measured by the scattering method calibrated by the sensor reading, there will be a certain error in the measured value and the accuracy is low.

[0004] In summary, the problems existing in the relevant technologies need to be solved urgently. Utility Model Content

[0005] The purpose of the utility model is to solve one of the technical problems existing in the related art to at least a certain extent.

[0006] Therefore, one object of the utility model is to provide a bacterial turbidity meter.

[0007] In order to achieve the above technical objectives, the technical solutions adopted by the utility model include:

[0008] On the one hand, the present invention provides a bacterial turbidity meter, comprising:

[0009] A main circuit board, a driving circuit, a lamp, an analog-to-digital conversion circuit, a first photodiode, a light barrier, a first convex lens, a second photodiode, and a second convex lens; the first convex lens and the second convex lens are of the same model;

[0010] The main circuit board is connected to the lamp through the driving circuit; the first convex lens and the optical path of the lamp are arranged in parallel, the light bar is arranged on the side of the first convex lens away from the optical path of the lamp, the light bar includes a hole, the hole is arranged at the focal position of the first convex lens, and the line connecting the center position of the hole and the center point of the first convex lens is perpendicular to the optical path of the lamp; the first photodiode is arranged on the side of the light bar away from the first convex lens, and the first photodiode is arranged at the hole;

[0011] The center point of the second convex lens is located on the light path of the lamp, the second photodiode is arranged on a side of the second convex lens away from the second convex lens, and the second photodiode is arranged at the focus of the second convex lens;

[0012] The first photodiode and the second photodiode are connected to the main circuit board through the analog-to-digital conversion circuit.

[0013] In addition, a bacterial turbidity meter according to the above embodiment of the utility model may also have the following additional technical features:

[0014] Furthermore, in an embodiment of the present invention, the lamp is an LED lamp.

[0015] Furthermore, in an embodiment of the present invention, the first photodiode is a square photodiode with a side length of 4 mm.

[0016] Furthermore, in an embodiment of the present invention, the size of the holes on the light barrier is greater than or equal to 4 mm.

[0017] Furthermore, in an embodiment of the present invention, the second photodiode is a square photodiode with a side length of 10 mm.

[0018] Furthermore, in an embodiment of the present invention, the driving circuit includes a constant current source.

[0019] Furthermore, in an embodiment of the present utility model, the bacterial turbidity meter further comprises a sample positioning chamber, the sample positioning chamber is used for placing the sample, and the sample positioning chamber is arranged between the lamp and the second convex lens.

[0020] Furthermore, in an embodiment of the present invention, the main circuit board includes a single-chip microcomputer chip.

[0021] Furthermore, in one embodiment of the present invention, the single-chip microcomputer chip is a STC12 series single-chip microcomputer chip or a STM32 series single-chip microcomputer chip.

[0022] The advantages and beneficial effects of the present invention will be partially given in the following description, partially become apparent from the following description, or be understood through the practice of the present invention:

[0023] The present application discloses a bacterial turbidity meter, comprising a main circuit board, a driving circuit, a lamp, an analog-to-digital conversion circuit, a first photodiode, a light bar, a first convex lens, a second photodiode and a second convex lens; the first convex lens and the second convex lens are of the same model; the main circuit board is connected to the lamp through the driving circuit; the optical paths of the first convex lens and the lamp are arranged in parallel, the light bar is arranged on the side of the first convex lens away from the optical path of the lamp, the light bar includes a hole, the hole is arranged at the focal position of the first convex lens, and the line connecting the center position of the hole and the center point of the first convex lens is perpendicular to the optical path of the lamp; the first photodiode is arranged on the side of the light bar away from the first convex lens, and the first photodiode is arranged at the hole; the center point of the second convex lens is located on the optical path of the lamp, the second photodiode is arranged on the side of the second convex lens away from the second convex lens, and the second photodiode is arranged at the focus of the second convex lens; the first photodiode and the second photodiode are connected to the main circuit board through the analog-to-digital conversion circuit. The bacterial turbidity meter can improve the accuracy of detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic structural diagram of a bacterial turbidity meter provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0025] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0026] In the description of the present utility model, it is necessary to understand that the terms "length", "upper", "lower", "front", "back", "left", "right", "top", "inner", "outer", "axial", "radial", "circumferential" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, unless otherwise specified, "multiple" means two or more.

[0027] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] A bacterial turbidimeter is an instrument used to measure the microbial content of water or liquids. It detects the turbidity of the liquid to infer the number of bacteria, algae or other microorganisms in it. Turbidity is the degree to which a liquid becomes cloudy due to the presence of these tiny organisms. Bacterial turbidimeters usually use the principle of light scattering. When light is irradiated onto a liquid sample, microorganisms scatter the light. By measuring the intensity of the scattered light, the turbidity can be determined and the bacterial concentration can be indirectly estimated. This equipment is often used in water quality monitoring, sewage treatment, food and beverage industries, and scientific research.

[0029] In the related technology, the bacterial turbidity meters on the market mainly use the scattering measurement principle, and believe that the relationship curve between the bacterial turbidity measured by the scattering method and the scattered light intensity received by the sensor end is a linear relationship. However, in actual measurements, the light beam from the light source to the scattering area of ​​the bacterial liquid to be measured and the scattered light generated by the area during measurement to the photocell will pass through a certain distance of the bacterial liquid to be measured, and will therefore be attenuated. Therefore, if the bacterial turbidity is directly measured by the scattering method calibrated by the sensor reading, there will be a certain error in the measured value and the accuracy is low.

[0030] In view of this, a bacterial turbidity meter is provided in an embodiment of the present application, comprising a main circuit board, a driving circuit, a lamp, an analog-to-digital conversion circuit, a first photodiode, a light bar, a first convex lens, a second photodiode and a second convex lens; the main circuit board is connected to the lamp through the driving circuit; the optical paths of the first convex lens and the lamp are arranged in parallel, the light bar is arranged on the side of the first convex lens away from the optical path of the lamp, the light bar includes a hole, and the line connecting the center position of the hole and the focus of the first convex lens is perpendicular to the optical path of the lamp; the first photodiode is arranged on the side of the light bar away from the first convex lens, and the first photodiode is arranged at the hole; the focus of the second convex lens is located on the optical path of the lamp, and the second photodiode is arranged on the side of the second convex lens away from the second convex lens; the first photodiode and the second photodiode are connected to the main circuit board through the analog-to-digital conversion circuit. The bacterial turbidity meter can improve the accuracy of detection.

[0031] Below, in conjunction with specific drawings, a bacterial turbidity meter provided in an embodiment of the present application is described in detail.

[0032] The present application provides a bacterial turbidity meter which can be applied to the technical field of instrumentation. Figure 1 , a bacterial turbidity meter provided in the embodiment of the present application mainly comprises:

[0033] Main circuit board, driving circuit, lamp 4, analog-to-digital conversion circuit, first photodiode 1, light barrier 2, first convex lens 3, second photodiode 6 and second convex lens 5;

[0034] The main circuit board is connected to the lamp 4 through the driving circuit; the first convex lens 3 and the optical path of the lamp 4 are arranged in parallel, the light bar 2 is arranged on the side of the first convex lens 3 away from the optical path of the lamp 4, the light bar 2 includes a hole, the hole is arranged at the focal position of the first convex lens 3, and the line connecting the center position of the hole and the center point of the first convex lens 3 is perpendicular to the optical path of the lamp 4; the first photodiode 1 is arranged on the side of the light bar 2 away from the first convex lens 3, and the first photodiode 1 is arranged at the hole;

[0035] The center point of the second convex lens 5 is located on the light path of the lamp 4, the second photodiode 6 is arranged on a side of the second convex lens 5 away from the second convex lens 5, and the second photodiode 6 is arranged at the focus of the second convex lens 5;

[0036] The first photodiode 1 and the second photodiode 6 are connected to the main circuit board through the analog-to-digital conversion circuit.

[0037] In an embodiment of the present application, a bacterial turbidity meter is provided, which supports the adjustment of the height of the water injection rod, which is beneficial to reduce the probability of splashing liquid and improve the accuracy of dilution.

[0038] Specifically, the bacterial turbidity meter in the embodiment of the present application includes a main circuit board, a driving circuit, a lamp 4, an analog-to-digital conversion circuit, a first photodiode 1, a light bar 2, a first convex lens 3, a second photodiode 6, and a second convex lens 5. Among them, the main circuit board is the main processing device. For example, in some embodiments, the main circuit board may include any one or more processor chips including MCU single-chip microcomputer, PLC (programmable logic controller), FPGA, CPLD, DSP, ARM, etc. For example, the single-chip microcomputer chip can be set to STC12 series single-chip microcomputer chip or STM32 series single-chip microcomputer chip. Of course, the specific chip selection can be flexibly adjusted as needed, and this is not limited in the embodiment of the present application. In the embodiment of the present application, the driving circuit is used to drive the lamp 4, and the main circuit board can be connected to the lamp 4 through the driving circuit, so as to realize the switch control of the lamp 4. Specifically, the driving circuit can include a constant current source with a controllable output current size, and the main circuit board can transmit a related electrical signal to the driving circuit, thereby controlling the driving circuit to output currents of different sizes, so that the brightness of the light emitted by the lamp 4 can be flexibly adjusted, which is conducive to the detection of various samples.

[0039] In the embodiment of the present application, a lamp 4, two convex lenses, denoted as a first convex lens 3 and a second convex lens 5, and two photodiodes, denoted as a first photodiode 1 and a second photodiode 6, can be provided in the bacterial turbidity meter. Among them, the lamp 4 can use an LED lamp, the first convex lens 3 and the first photodiode 1 are used in combination, the second convex lens 5 and the second photodiode 6 are used in combination, and the first convex lens 3 and the second convex lens 5 are of the same model. Specifically, in the embodiment of the present application, the optical paths of the first convex lens 3 and the lamp 4 are arranged in parallel, that is, the first convex lens 3 is placed in a direction perpendicular to the optical path in a manner parallel to the optical path. The first convex lens 3 can be used to collect scattered light during sample measurement. In the embodiment of the present application, the bacterial turbidity meter is also provided with a light bar 2, and the light bar 2 includes a hole, the hole is arranged at the focal position of the first convex lens 3, and the line connecting the center position of the hole and the center point of the first convex lens 3 is perpendicular to the optical path of the lamp 4, so that the scattered light can be gathered to the hole through the first convex lens 3, thereby reducing the interference of other optical signals. In the embodiment of the present application, a first photodiode 1 may be disposed behind the hole of the light barrier 2. The first photodiode 1 is disposed on the side of the light barrier 2 away from the first convex lens 3, and it may be used to receive scattered light signals from the sample during measurement. In some embodiments, the first photodiode 1 may be a square photodiode with a side length of 4 mm. In this case, the size of the hole included in the light barrier 2 may be set to a side length of 4 mm, or may be set to be greater than 4 mm, and the present application does not impose any limitation on this.

[0040] In the embodiment of the present application, the center point of the second convex lens 5 is located on the light path of the lamp 4, and the second photodiode 6 is arranged on the side of the second convex lens 5 away from the second convex lens 5, and is located at the focus of the second convex lens 5. After the light path passes through the second convex lens 5, it can be received by the second photodiode 6. In the embodiment of the present application, the second convex lens 5 can be used to converge the direct light during the sample measurement, and the converged direct light is received by the second photodiode 6. In some embodiments, the second photodiode 6 can be a square photodiode with a side length of 10 mm.

[0041] In the embodiment of the present application, when light propagates in a uniform medium, the light absorption law is: 测 =I0e -αL I0 is the original light intensity, I 测 is the light intensity after passing through a distance of length L (the sample to be tested and the convex lens), and α is the absorption coefficient. It can be seen that when the thickness of the absorption layer increases in arithmetic progression, the power density of the light decreases in geometric progression. The absorption rate of a substance depends on the properties of the substance and is related to the wavelength, but has nothing to do with the power density of the incident light and the thickness of the substance. When the light passes through the sample and the second convex lens 5 and is directly incident on the second photodiode 6, the absorbance value of the light after passing through the sample can be expressed as:

[0042]

[0043] In the formula, A 直射 It indicates the absorbance value after direct light passes through the sample, I 0直射 represents the light intensity detected by the second photodiode 6 when there is no sample (or the sample chamber is pure water), I 直射 It represents the light intensity detected by the second photodiode 6 when there is a sample.

[0044] Similarly, when light passes through the sample and the first convex lens 3 and is scattered on the first photodiode 1, the absorbance value can be expressed as:

[0045]

[0046] In the formula, A 散射 It represents the absorbance value of scattered light after passing through the sample, I 0散射 Represents the actual scattered light intensity, I 散射 It represents the light intensity detected by the first photodiode 1 when there is a sample.

[0047] Since the first convex lens 3 and the second convex lens 5 in the embodiment of the present application are of the same model, during the detection, the medium path of the direct light and the scattered light is the same (both are the sample to be tested and the convex lens), therefore, it can be considered that A 直射 and A 散射 Therefore, in the embodiment of the present application, when using the bacterial turbidity meter, the relevant light intensity can be read out by the first photodiode 1 and the second photodiode 6, and then the real scattered light intensity can be calculated based on the read data. According to the theory, the relationship curve between the real scattered light intensity and the bacterial turbidity is a linear relationship, and then the accurate bacterial turbidity value can be obtained.

[0048] In the embodiment of the present application, the bacterial turbidity meter may further include a sample positioning chamber, which is used to place the sample, and the sample positioning chamber is arranged between the lamp 4 and the second convex lens 5. Specifically, the sample positioning chamber can be arranged on a side close to the lamp 4. After the sample is placed in, the light irradiated by the lamp 4 will pass through the sample, and the scattered light will enter the first convex lens 3, and the direct light will enter the second convex lens 5.

[0049] In the description of this specification, the description with reference to the terms "one embodiment", "another embodiment" or "certain embodiments" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0050] Although the embodiments of the present invention have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A bacterial turbidity meter, characterized in that: include: A main circuit board, a driving circuit, a lamp, an analog-to-digital conversion circuit, a first photodiode, a light barrier, a first convex lens, a second photodiode, and a second convex lens; the first convex lens and the second convex lens are of the same model; The main circuit board is connected to the lamp through the driving circuit; the first convex lens and the optical path of the lamp are arranged in parallel, the light bar is arranged on the side of the first convex lens away from the optical path of the lamp, the light bar includes a hole, the hole is arranged at the focal position of the first convex lens, and the line connecting the center position of the hole and the center point of the first convex lens is perpendicular to the optical path of the lamp; the first photodiode is arranged on the side of the light bar away from the first convex lens, and the first photodiode is arranged at the hole; The center point of the second convex lens is located on the light path of the lamp, the second photodiode is arranged on a side of the second convex lens away from the second convex lens, and the second photodiode is arranged at the focus of the second convex lens; The first photodiode and the second photodiode are connected to the main circuit board through the analog-to-digital conversion circuit.

2. A bacterial turbidity meter according to claim 1, characterized in that: The lamp adopts LED lamp.

3. A bacterial turbidity meter according to claim 1, characterized in that: The first photodiode is a square photodiode with a side length of 4 mm.

4. A bacterial turbidity meter according to claim 3, characterized in that: The size of the hole on the light barrier is greater than or equal to 4 mm.

5. A bacterial turbidity meter according to claim 1, characterized in that: The second photodiode is a square photodiode with a side length of 10 mm.

6. A bacterial turbidity meter according to claim 1, characterized in that: The driving circuit includes a constant current source.

7. A bacterial turbidity meter according to claim 1, characterized in that: The bacterial turbidity meter further comprises a sample positioning chamber, which is used for placing a sample and is arranged between the lamp and the second convex lens.

8. A bacterial turbidity meter according to claim 1, characterized in that: The main circuit board includes a single-chip microcomputer chip.

9. A bacterial turbidity meter according to claim 8, characterized in that: The single-chip microcomputer chip is a STC12 series single-chip microcomputer chip or a STM32 series single-chip microcomputer chip.

Images