Turbidity sensor calibration tool and low-range turbidity sensor

Abstract

The utility model relates to the technical field of turbidity sensors, and provides a turbidity sensor calibration tool and a low-range turbidity sensor.The turbidity sensor calibration tool comprises a calibration barrel, a standard liquid bag and a hanging plate, the calibration barrel is suitable for being detachably connected with a detection module of the turbidity sensor, the standard liquid bag is communicated with the calibration barrel through a pipe body, and the hanging plate is arranged on the calibration barrel. The tube body is provided with an on-off unit used for controlling the on-off of a standard liquid flow path on the tube body, the hanging plate is provided with a first fixing position and a second fixing position, when the standard liquid bag is connected to the first fixing position, standard liquid in the standard liquid bag is suitable for flowing to the calibration barrel, and when the standard liquid bag is connected to the second fixing position, the standard liquid in the standard liquid bag is suitable for flowing to the calibration barrel. And the standard liquid in the calibration barrel is suitable for flowing to the standard liquid bag, so that the problems that the standard liquid is easy to splash and the operation is difficult due to the mode that the turbidity standard liquid is injected into the low-range turbidity sensor flow cell to calibrate the low-range turbidity sensor in the existing low-range turbidity sensor can be effectively solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of turbidity sensors, in particular to a turbidity sensor calibration tool and a low-range turbidity sensor. BACKGROUND

[0002] The low-range turbidity sensor adopts a high-performance laser light source, a light-avoiding flow cell, and a defoaming design, and is suitable for long-term stable operation in industrial sites. Application fields: tap water, secondary water supply, pipe network terminal water, direct drinking water, membrane filtration water, swimming pools, surface water, etc. The low-range turbidity sensor can be used alone or integrated in a multi-parameter monitor case.

[0003] The low-range turbidity sensor is widely used in monitoring occasions with high requirements for water quality, and can realize accurate detection and control of low-turbidity water quality. The water quality turbidity index can reflect the physical condition of the water quality, and can directly reflect the transparency and clarity of the water. High turbidity may mean that the water contains more silt, algae, microorganisms or other particulate matter, and high turbidity will affect the disinfection effect of tap water. Suspended particles can shield microorganisms, reduce the bactericidal effect of chlorine or other disinfectants, and increase the survival risk of pathogens such as bacteria and viruses.

[0004] The drinking water standards of various countries usually make clear provisions for turbidity. By controlling turbidity, the water plant can ensure that the water meets health standards, reduce the health risks of consumers, and the monitoring of turbidity can also help the water supply plant to find problems in the water treatment system, such as filter failure, excessive pipe sediment, etc., so as to maintain and optimize the water treatment process in a timely manner. Through monitoring and controlling the turbidity of tap water, the quality and safety of residents' drinking water can be effectively guaranteed.

[0005] The low-range turbidity sensor is an optical sensor, and in order to ensure the reliability of the sensor, it needs to be regularly maintained and calibrated. At present, in the process of field use calibration and maintenance of the low-range turbidity sensor, the low-range turbidity sensor is calibrated by injecting turbidity standard solution into the flow cell of the low-range turbidity sensor. There are the following problems: it is inconvenient to inject turbidity standard solution into the flow cell, the flow cell is usually fixed in a cabinet or wall-mounted, connected with several pipelines at the bottom, and inconvenient to disassemble, when several hundred milliliters of turbidity standard solution need to be injected, the standard solution is easy to splash, and the operation is difficult. For example, the prior art disclosed in Chinese Patent No. CN 219266268 U, a low-turbidity sensor batch calibration device, needs to be equipped with a special low-turbidity sensor batch calibration device, which is not suitable for product operation and maintenance stage, and is not suitable for rapid calibration of a single low-range turbidity sensor in actual field. SUMMARY

[0006] The present application aims to at least solve one of the technical problems in the related art. To this end, the present application proposes a turbidity sensor calibration tool and a low-range turbidity sensor, which can effectively solve the problem of easy splashing of the standard solution and difficult operation caused by the current low-range turbidity sensor calibration method of injecting the standard solution into the low-range turbidity sensor flow cell.

[0007] According to the first aspect of the present application, a turbidity sensor calibration tool is provided, comprising:

[0008] A calibration barrel adapted to be detachably connected to a detection module of a turbidity sensor;

[0009] A standard solution bag in communication with the calibration barrel through a pipe body, wherein the pipe body is provided with an on-off unit for controlling the on-off of a standard solution flow path on the pipe body;

[0010] A hanging plate provided with a first fixing position and a second fixing position, and the standard solution bag is selectively detachably connected to one of the first fixing position and the second fixing position;

[0011] When the standard solution bag is connected to the first fixing position, the standard solution in the standard solution bag is adapted to flow to the calibration barrel;

[0012] When the standard solution bag is connected to the second fixing position, the standard solution in the calibration barrel is adapted to flow to the standard solution bag.

[0013] It can be understood that the turbidity sensor calibration tool according to the first aspect of the present application is applied to a turbidity sensor (more specifically, a low-range turbidity sensor, but it should be noted that even if it is a turbidity sensor of other types except for low-range, the application of the turbidity sensor calibration tool according to the present application is also considered to fall within the protection scope of the present application), and the specific working principle is as follows:

[0014] S1: Injecting standard solution: the operator suspends and fixes the calibration barrel and the standard solution bag on the hanging plate, and the vertical height of the standard solution bag is higher than the A point (i.e. the first fixing position) of the calibration barrel. Connect the standard solution bag with the calibration barrel by a pipe body (preferably a hose), open the on-off unit to conduct the standard solution flow path (preferably a clamp valve), slowly squeeze the standard solution bag, and the standard solution slowly flows into the calibration barrel through the pipe body.

[0015] S2: Calibration process: remove the detection module of the low-range turbidity sensor and install it on the calibration barrel. After the detection signal value is stable, collect the signal, input the standard solution concentration value at the controller end, and confirm the calibration parameters. Then install the detection module back to the low-range turbidity sensor.

[0016] S3: Recycle the standard solution: Re-hang the standard solution bag, and make it vertically higher than the B point of the calibration tank (i.e. the second fixed position). Turn on the on-off unit to open the standard solution flow path (preferably a clamp valve), and the standard solution in the calibration tank flows back to the standard solution bag under the action of gravity.

[0017] At this point, the calibration of one point is completed, and the above steps are repeated to use other concentrations of standard solution to complete the multi-point calibration of the low-range turbidity sensor.

[0018] The turbidity sensor calibration tool of the first aspect embodiment of the present application can produce the following technical effects:

[0019] The structure of the turbidity sensor calibration tool of the present application is simple, and rapid calibration can be achieved. One person can operate it. Compared with the existing flow cell that injects standard solution into the turbidity sensor, the operation of injecting the turbidity standard solution into the calibration tank in the embodiment of the present application is more convenient, and it is not easy to appear bubble interference measurement, and the completed calibration standard solution can be recycled from the calibration tank to the standard solution bag to realize secondary use.

[0020] It can also be understood that the turbidity standard solution can also be completely recycled from the flow cell, avoiding the influence of standard solution residue discharge on the environment while realizing the secondary use of recycled turbidity standard solution.

[0021] Specifically, the calibration tank is used as a container for the standard solution used when calibrating the low-range turbidity sensor, and a container for the light source and detection signal emitted by the detection module of the low-range turbidity sensor. In order to ensure signal consistency, the calibration tank and the flow cell of the low-range turbidity sensor are made of the same material.

[0022] According to the turbidity sensor calibration tool provided by the embodiment, when the standard solution bag is connected to the first fixed position, the bottom of the standard solution cavity in the standard solution bag is higher than the highest liquid level of the standard solution cavity in the calibration tank, so that the standard solution in the standard solution bag is suitable for flowing to the calibration tank. When the highest liquid level of the standard solution cavity in the calibration tank is the standard solution in the standard solution bag completely flows into the calibration tank, the liquid level of the standard solution in the calibration tank;

[0023] When the standard solution bag is connected to the second fixed position, the highest liquid level of the standard solution cavity in the standard solution bag is lower than the bottom of the standard solution cavity in the calibration tank, so that the standard solution in the calibration tank is suitable for flowing to the standard solution bag. When the highest liquid level of the standard solution cavity in the standard solution bag is the standard solution in the calibration tank completely flows into the standard solution bag, the liquid level of the standard solution in the standard solution bag.

[0024] It can be understood that the embodiment utilizes the siphon principle to realize the directional and rapid flow of the standard solution between the standard solution bag and the calibration tank, without the need for additional pump body, and the structure is simpler.

[0025] According to the turbidity sensor calibration tool provided in the embodiment, the pipe body is a hose, the material of the hose is transparent silica gel, and the on-off unit comprises a clamp valve.

[0026] It can be understood that, in the embodiment, the pipe body is further selected as a hose, so that the hose can be flexibly bent and does not interfere with the movement of the standard solution bag during switching of the standard solution bag between the first fixing position and the second fixing position.

[0027] In other embodiments, the clamp valve can also be replaced by a large syringe. Compared with the clamp valve, the cost of the large syringe is much higher.

[0028] According to the turbidity sensor calibration tool provided in the embodiment, the side of the calibration barrel is hollow to form a hidden storage groove, and the brush body can be stored in the hidden storage groove.

[0029] According to the turbidity sensor calibration tool provided in the embodiment, the brush body is a sponge brush, the diameter of the sponge brush is greater than the hole diameter of the flow cell internal pipe hole of the turbidity sensor, the sponge brush can be deeply inserted into the flow cell internal pipe hole of the turbidity sensor to clean the flow cell internal pipe hole of the turbidity sensor, and the diameter of the sponge brush is 4 mm greater than the hole diameter of the flow cell internal pipe hole of the turbidity sensor.

[0030] Specifically, the hole diameter of the flow cell internal pipe hole of the turbidity sensor is φ8 mm, and the diameter of the sponge brush is 12 mm.

[0031] It can be understood that the hidden sponge brush is easy to clean the flow cell, the diameter of the sponge brush is slightly greater than the diameter of the flow cell internal pipe hole, the sponge brush can clean without dead angle, deposition of stains is prevented, and normal operation of the sensor is ensured.

[0032] After long-time use, stains may be deposited on the inner wall of the flow cell. It can be understood that the sponge brush can also be used to clean the inner wall of the flow cell of the low-range turbidity sensor.

[0033] According to the turbidity sensor calibration tool provided in the embodiment, the standard solution bag is selectively detachably connected to one of the first fixing position and the second fixing position in a hanging manner through a hanging device.

[0034] According to the turbidity sensor calibration tool provided in the embodiment, the standard solution cavity in the calibration barrel is greater than the standard solution bag filled with standard solution, so that the standard solution bag can be placed in the standard solution cavity in the calibration barrel for sealed storage after being filled with standard solution.

[0035] According to the turbidity sensor calibration tool provided in the embodiment,

[0036] The size of the calibration barrel is 140mm*130mm*112mm, the material is black POM, and / or

[0037] The size of the calibration liquid bag is 200mm*140mm*50mm, the material is transparent PP, the calibration liquid bag can be put into the calibration barrel after being filled with calibration liquid, sealed and stored, and convenient for transportation, and / or

[0038] The diameter of the pipe body is φ8mm, the length is 0.7m, and the material is transparent silica gel pipe. The material is stable and does not react with the calibration liquid.

[0039] According to the second aspect of the present application, a low-range turbidity sensor is provided, which comprises any one of the turbidity sensor calibration tools provided in the first aspect of the present application.

[0040] The turbidity sensor is provided with a flow cell and a detection module, and the detection module is selectively detachably connected to the flow cell and the calibration barrel.

[0041] According to the low-range turbidity sensor provided in the present embodiment, the detection module is adapted to emit a light source and detect a signal to detect the turbidity of the calibration liquid in the flow cell and the calibration barrel.

[0042] Additional aspects and advantages of the present application will be given in part in the following description, and will become apparent from the following description, or will be understood by those skilled in the art through practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related art, the following will briefly introduce the drawings needed to be used in the embodiment or related art description. Obviously, the drawings in the following description are only some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0044] Fig. 1 is a structure schematic diagram of the normal online measurement state of the low-range turbidity sensor provided in the present application;

[0045] Fig. 2 is a structure schematic diagram of the low-range turbidity sensor provided in the present application injecting calibration liquid and calibrating;

[0046] Fig. 3 is a structure schematic diagram of the low-range turbidity sensor provided in the present application after calibration is completed and the calibration liquid is recovered;

[0047] Reference signs:

[0048] 1, calibration barrel; 2, calibration liquid bag; 3, hose; 4, clamp valve; 5, hidden storage groove; 6, sponge brush; 7, low-range turbidity sensor; 8, detection module; 9, flow cell. DETAILED DESCRIPTION

[0049] In order to make the purpose, technical scheme and advantages of the present application clearer, the technical scheme of the present application will be described clearly and completely below in combination with the drawings in the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0050] The technical scheme of the present application will be described below in combination with Figs. 1-3 The turbidity sensor calibration tool and low-range turbidity sensor provided by the present application can effectively solve the problem of easy splashing of calibration liquid and difficult operation caused by the current low-range turbidity sensor calibration method of injecting calibration liquid into the low-range turbidity sensor flow cell.

[0051] It should be noted that although the distribution and connection modes between the related technical features are shown in the structural schematic diagram, in some embodiments, the related technical features can be completed in different distribution and connection modes to achieve the methods shown or described.

[0052] According to the first aspect of the present application, a turbidity sensor 7 calibration tool comprises:

[0053] A calibration barrel 1, which is suitable for detachable connection with the detection module of the turbidity sensor 7;

[0054] A calibration liquid bag 2, which is in communication with the calibration barrel 1 through a pipe body, and the pipe body is provided with an on-off unit for controlling the on-off of the calibration liquid flow path on the pipe body;

[0055] A hanging plate, which is provided with a first fixing position and a second fixing position, and the calibration liquid bag 2 is selectively detachably connected to one of the first fixing position and the second fixing position:

[0056] When the calibration liquid bag 2 is connected to the first fixing position, the calibration liquid in the calibration liquid bag 2 is suitable to flow to the calibration barrel 1;

[0057] When the calibration liquid bag 2 is connected to the second fixing position, the calibration liquid in the calibration barrel 1 is suitable to flow to the calibration liquid bag 2.

[0058] It can be understood that the turbidity sensor 7 calibration tool of the first aspect of the present application is applied to a low-range turbidity sensor 7, and the specific working principle is: It can be understood that the turbidity sensor 7 calibration tool of the first aspect of the present application is applied to a low-range turbidity sensor 7, and the specific working principle is:

[0059] S1: inject the standard solution: the operator suspends and fixes the calibration barrel 1 and the standard solution bag 2 on the hanging plate, the vertical height of the standard solution bag 2 is higher than the A point (i.e. the first fixed position) of the calibration barrel 1. Connect the standard solution bag 2 with the calibration barrel 1 by the pipe body (preferably the hose 3), open the on-off unit to conduct the standard solution flow path (preferably the clamp valve 4), slowly squeeze the standard solution bag 2, and the standard solution slowly flows into the calibration barrel 1 through the pipe body.

[0060] S2: calibration process: remove the detection module of the low-range turbidity sensor 7 and install it on the calibration barrel 1. After the detection signal value is stable, collect the signal, input the standard solution concentration value at the controller end, and confirm the calibration parameters. Then install the detection module back to the low-range turbidity sensor 7.

[0061] S3: recover the standard solution: re-suspend the standard solution bag 2, so that its vertical height is lower than the B point (i.e. the second fixed position) of the calibration barrel 1. Open the on-off unit to conduct the standard solution flow path (preferably the clamp valve 4), and the standard solution in the calibration barrel 1 flows back to the standard solution bag 2 under the action of gravity.

[0062] At this point, the calibration of one point is completed, and by repeating the above steps and using other concentrations of standard solution, the low-range turbidity sensor 7 can be calibrated with multiple points of standard solution.

[0063] The turbidity sensor 7 calibration tool of the first aspect embodiment of the present application can produce the following technical effects:

[0064] The structure of the turbidity sensor 7 calibration tool of the present application is simple, and it can realize rapid calibration, which can be operated by a single person. Compared with the existing flow cell 9 that injects the standard solution into the turbidity sensor 7, the operation of injecting the turbidity standard solution into the calibration barrel 1 of the present embodiment is more convenient, and it is not easy to appear bubble interference measurement, and the calibrated standard solution can be recovered from the calibration barrel 1 to the standard solution bag 2 for secondary use.

[0065] It can also be understood that the turbidity standard solution can also be completely recovered from the flow cell 9, which can avoid the influence of standard solution residue discharge on the environment while realizing the secondary use of the recovered turbidity standard solution.

[0066] Specifically, the calibration barrel 1 is used as a container for the standard solution used in the calibration of the low-range turbidity sensor 7, and a container for the light source and detection signal emitted by the detection module of the low-range turbidity sensor 7. In order to ensure signal consistency, the calibration barrel 1 and the flow cell 9 of the low-range turbidity sensor 7 are made of the same material.

[0067] According to the turbidity sensor 7 calibration tool provided by the embodiment, when the standard solution bag 2 is connected to the first fixing position, the bottom of the standard solution cavity in the standard solution bag 2 is higher than the highest liquid level of the standard solution cavity in the standard barrel 1, so that the standard solution in the standard solution bag 2 is adapted to flow to the standard barrel 1, and when the highest liquid level of the standard solution cavity in the standard barrel 1 is equal to the complete flow of the standard solution in the standard solution bag 2 into the standard barrel 1, the liquid level of the standard solution in the standard barrel 1 is

[0068] According to the turbidity sensor 7 calibration tool provided by the embodiment, when the standard solution bag 2 is connected to the first fixing position, the bottom of the standard solution cavity in the standard solution bag 2 is higher than the highest liquid level of the standard solution cavity in the standard barrel 1, so that the standard solution in the standard solution bag 2 is adapted to flow to the standard barrel 1, and when the highest liquid level of the standard solution cavity in the standard barrel 1 is equal to the complete flow of the standard solution in the standard solution bag 2 into the standard barrel 1, the liquid level of the standard solution in the standard barrel 1 is

[0069] It can be understood that the embodiment utilizes the siphon principle to realize the directional and rapid flow of the standard solution between the standard solution bag 2 and the standard barrel 1, and does not need to additionally arrange a pump body, so that the structure is simpler.

[0070] According to the turbidity sensor 7 calibration tool provided by the embodiment, the pipe body is a soft tube 3, the material of the soft tube 3 is transparent silica gel, and the on-off unit comprises a clamp valve 4.

[0071] It can be understood that the pipe body is further selected as the soft tube 3 in the embodiment, so that the soft tube 3 can be flexibly bent and does not interfere with the movement of the standard solution bag 2 during the switching of the standard solution bag 2 between the first fixing position and the second fixing position.

[0072] In other embodiments, the clamp valve 4 can also be replaced by a large syringe. Compared with the clamp valve 4, the cost of the large syringe is much higher.

[0073] According to the turbidity sensor 7 calibration tool provided by the embodiment, the calibration tool further comprises a brush body, the side of the standard barrel 1 is hollow to form a hidden storage groove 5, and the brush body can be stored in the hidden storage groove 5.

[0074] According to the turbidity sensor 7 calibration tool provided by the embodiment, the brush body is a sponge brush 6, the diameter of the sponge brush 6 is greater than the inner tube hole diameter of the flow cell 9 of the turbidity sensor 7, the sponge brush 6 can be deeply inserted into the inner tube hole of the flow cell 9 of the turbidity sensor 7 to clean the inner tube hole of the flow cell 9 of the turbidity sensor 7, and the diameter of the sponge brush 6 is 4 mm greater than the inner tube hole diameter of the flow cell 9 of the turbidity sensor 7.

[0075] Specifically, the inner tube hole diameter of the flow cell 9 of the turbidity sensor 7 is φ8 mm, and the diameter of the sponge brush 6 is 12 mm.

[0076] It can be understood that the hidden sponge brush 6 is easy to clean the inside of the flow cell 9, and the sponge brush 6 is slightly larger than the diameter of the inner hole of the flow cell 9, so that it can be cleaned without dead angle, prevent the deposition of stains, and ensure the normal operation of the sensor.

[0077] And after a long time of use, the inner wall of the flow cell 9 may have stains deposited, and it can be understood that the sponge brush 6 can also be used to clean the inner wall of the flow cell 9 of the low-range turbidity sensor 7.

[0078] According to the turbidity sensor 7 calibration tool provided in the embodiment, the standard solution bag 2 is selectively detachably connected to one of the first fixing position and the second fixing position in a hanging manner through the hanging device.

[0079] According to the turbidity sensor 7 calibration tool provided in the embodiment, the standard solution cavity in the standard solution barrel 1 is larger than the standard solution bag 2 filled with standard solution, so that the standard solution bag 2 can be placed in the standard solution cavity in the standard solution barrel 1 for sealed preservation after being filled with standard solution.

[0080] According to the turbidity sensor 7 calibration tool provided in the embodiment,

[0081] The size of the standard solution barrel 1 is 140mm*130mm*112mm, and the material is black POM, and / or

[0082] The size of the standard solution bag 2 is 200mm*140mm*50mm, and the material is transparent PP. The standard solution bag 2 can be placed in the standard solution barrel 1 for sealed preservation after being filled with standard solution, which is convenient for transportation, and / or

[0083] The diameter of the hose 3 is φ8mm, the length is 0.7m, and the material is transparent silicone tube. The material is stable and does not react with the standard solution.

[0084] According to the second aspect of the application, a low-range turbidity sensor 7 is provided, which comprises the turbidity sensor 7 calibration tool provided in any one of the first aspect embodiments;

[0085] The turbidity sensor 7 is provided with a flow cell 9 and a detection module, and the detection module is selectively detachably connected to the flow cell 9 and the standard solution barrel 1.

[0086] According to the low-range turbidity sensor 7 provided in the embodiment, the detection module is adapted to emit a light source and detect a signal to detect the turbidity of the standard solution in the flow cell 9 and the standard solution barrel 1.

[0087] The device embodiments described above are merely illustrative, wherein the units illustrated as separate components can or can not be physically separate, and the components illustrated as units can or can not be physical units, i.e., can be located in one place, or can be distributed to multiple network units. Part or all of the modules can be selected to achieve the purposes of the embodiments according to actual needs. Those skilled in the art can understand and implement without creative labor.

[0088] Through the description of the above embodiments, those skilled in the art can clearly understand that the embodiments can be realized by means of software plus necessary general hardware platforms, and of course can also be realized by hardware. Based on such understanding, the above technical solutions, essentially or in other words, the part that contributes to the prior art, can be embodied in the form of a software product. The computer software product can be stored in a computer readable storage medium, such as a ROM / RAM, a magnetic disk, an optical disk, etc., and includes a plurality of instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) execute the methods of the various embodiments or some parts of the embodiments.

[0089] Finally, it should be noted that the above embodiments are only used to illustrate the present application, and are not intended to limit the present application. Although the present application is described in detail with reference to the embodiments, those skilled in the art should understand that various combinations, modifications or equivalent replacements of the technical solutions of the present application do not deviate from the spirit and scope of the present application, and should be covered in the scope of the claims of the present application.

Claims

1. A turbidity sensor calibration fixture, characterized by, The calibration tank is suitable for detachable connection with the detection module of the turbidity sensor. The calibration tank is suitable for detachable connection with the detection module of the turbidity sensor. The hanging plate is provided with a first fixing position and a second fixing position, and the calibration liquid bag is selectively detachably connected to one of the first fixing position and the second fixing position. When the calibration liquid bag is connected to the first fixing position, the calibration liquid in the calibration liquid bag is suitable for flowing to the calibration tank. When the calibration liquid bag is connected to the second fixing position, the calibration liquid in the calibration tank is suitable for flowing to the calibration liquid bag. When the calibration liquid bag is connected to the first fixing position, the bottom of the calibration liquid cavity in the calibration liquid bag is higher than the highest liquid level of the calibration liquid cavity in the calibration tank, so that the calibration liquid in the calibration liquid bag is suitable for flowing to the calibration tank.

2. The turbidity sensor calibration fixture of claim 1, wherein, When the calibration liquid bag is connected to the second fixing position, the highest liquid level of the calibration liquid cavity in the calibration liquid bag is lower than the bottom of the calibration liquid cavity in the calibration tank, so that the calibration liquid in the calibration tank is suitable for flowing to the calibration liquid bag. The pipe body is a flexible pipe, and the on-off unit includes a clamp valve.

3. The turbidity sensor calibration fixture of claim 1, wherein, The brush body is a sponge brush, and the diameter of the sponge brush is greater than the inner tube hole diameter of the flow cell of the turbidity sensor.

4. The turbidity sensor calibration fixture of claim 1, wherein, The calibration liquid bag is selectively detachably connected to one of the first fixing position and the second fixing position by a hanging device.

5. The turbidity sensor calibration fixture of claim 4, wherein, The calibration liquid cavity in the calibration tank is larger than the calibration liquid bag filled with calibration liquid, so that the calibration liquid bag can be placed in the calibration liquid cavity in the calibration tank for sealed preservation after being filled with calibration liquid.

6. The turbidity sensor calibration fixture of claim 5, wherein, 8. The turbidity sensor calibration tool according to any one of claims 1-7, wherein the size of the calibration tank is 140mm*130mm*112mm, the material is black POM, and / or the size of the calibration liquid bag is 200mm*140mm*50mm, the material is transparent PP, and / or the diameter of the pipe body is φ8mm, the length is 0.7m, and the material is transparent silicone tube.

7. The turbidity sensor calibration fixture of claim 1, wherein, The turbidity sensor calibration tool according to any one of claims 1-8 is included. The turbidity sensor is provided with a flow cell and a detection module, and the detection module is selectively detachably connected to the flow cell and the calibration tank. The detection module is suitable for emitting light source and detection signal to detect the turbidity of the calibration liquid in the flow cell and the calibration tank. ​ ​ 9. A low range turbidity sensor characterized by, ​ ​ 10. The low range turbidity sensor of claim 9, wherein, ​

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