CN110231311A - A kind of portable fiber-optic turbidity detection device - Google Patents

Abstract

The invention provides a portable optical fiber turbidity detection device, which includes a core board control module, a transmitting module, a probe, a receiving module and a temperature sensor. The core board control module controls the transmitting module to emit light signals, and the transmitting module and the receiving module are respectively connected through plastic optical fibers. The probe and the receiving module receive optical signal conditioning and transmit it to the core board control module. The temperature sensor detects the temperature of the water body to be measured and transmits it to the core board control module. The core board control module performs temperature compensation on the received data and supports it according to the fitting function. Vector regression calculation, the turbidity value of the water body to be measured is obtained and transmitted to the smart terminal through the Bluetooth module. The beneficial effect of the present invention: when detecting the turbidity of water body, the probe can be directly immersed in the water body, and the data transmission and real-time display can be controlled by APP. The turbidity detection device is not easy to carry, high cost, low accuracy and other problems.

Description

A portable optical fiber turbidity detection device

technical field

The invention relates to the technical field of water environment monitoring, in particular to a portable optical fiber turbidity detection device.

Background technique

As people pay more and more attention to life, health and sustainable development of the natural environment, water quality monitoring issues are getting more and more attention. Turbidity is the most direct standard to measure water quality, therefore, turbidity detection is very important. However, some turbidimeters on the market are generally expensive and bulky, which is inconvenient for field investigations. Some of them also need to be equipped with cleaning devices, and the equipment structure is complicated. These are costly and impractical for water quality monitoring in large-scale water areas, or for daily life applications, so there is a demand for low-cost, portable, and easy-to-operate turbidity sensors. The readings of the existing turbidity instruments are relatively fixed, and some need to install specific software on the computer, and the installation process is complicated, and the application is also troublesome. At the same time, most turbidity instruments can only be used to detect the collected sample solution, the process is cumbersome and easily affected.

In addition, the data processing method of the commonly used turbidity instrument: polynomial interpolation method, the accuracy is greatly affected by the sample points, and the selected sample points will also have a great impact on the measurement results; the look-up table method is very simple, but To be specific to each instrument, if multiple instruments use the same table, it may cause deviation; piecewise linearity is to divide the measurement curve into multiple segments, and calculate the slope of the broken line between the points through the calibrated points, so that Get the calculation formula of each section. When measuring data, first judge which section it is in, and then use the calculation formula of this section to calculate the turbidity value. If the standard point produces an error, it will also affect a certain section near it, but for accurate Accuracy will produce a certain error within a specific range, which will make the overall error larger.

Contents of the invention

In view of this, the embodiment of the present invention provides a portable optical fiber turbidity detection device.

An embodiment of the present invention provides a portable optical fiber turbidity detection device, including a core board control module, a transmitting module, a probe, a receiving module and a temperature sensor, the transmitting module includes a first transmitter and a second transmitter, the receiving The module includes a first receiver, a second receiver and a signal conditioning circuit. The probe is provided with a 3D printing ring, and the 3D printing ring is uniformly provided with a first interface, a second interface, a third interface and a third interface. Four interfaces, the first interface, the second interface, the third interface and the fourth interface are inserted and connected with a plastic optical fiber, and the first transmitter is connected to the first transmitter through a plastic optical fiber. An interface, the second transmitter is connected to the second interface through a plastic optical fiber, the first receiver is connected to the third interface through a plastic optical fiber, and the second receiver is connected to the third interface through a plastic optical fiber The plastic optical fiber is connected to the fourth interface, the first receiver and the second receiver are both connected to the signal conditioning circuit, the signal conditioning circuit and the temperature sensor are both connected to the core board control module, The core board control module is respectively connected to the first transmitter and the second transmitter, and the core board control module controls the first transmitter and the second transmitter to transmit optical signals in time division, and the The first receiver is used to receive the first transmitted light signal sent by the first transmitter and the second scattered light signal sent by the second transmitter and convert the received signal into a first transmitted voltage signal and a second transmitted light signal. The scattered voltage signal transmits the first transmitted voltage signal and the second scattered voltage signal to the signal conditioning circuit at the same time, and the second receiver is used for receiving the second transmitted light signal and the first transmitted light signal sent by the second transmitter. A transmitter sends out a first scattered light signal and converts the received signal into a second transmitted voltage signal and a first scattered voltage signal, and simultaneously transmits the second transmitted voltage signal and the first scattered voltage signal to the signal conditioning circuit, the signal conditioning circuit is used to condition the received two transmitted voltage signals and two scattered voltage signals and transmit them to the core board control module, and the temperature sensor is used to detect the temperature of the water body to be measured and transmit the temperature data to the The core board control module, the core board control module carries out temperature compensation to the voltage signal after the first transmission voltage signal, the second transmission voltage signal, the first scattering voltage signal, and the second scattering voltage signal conditioning, and the core board control The module calculates the ratio of the voltage signal after temperature compensation, calculates the ratio of the first transmission voltage signal and the first scattering voltage signal as the first ratio, calculates the ratio of the second transmission voltage signal and the second scattering voltage signal as the second ratio, and After temperature compensation, the first transmission voltage signal, the second transmission voltage signal, the first scattering voltage signal, the second scattering voltage signal, the first ratio and the second ratio are substituted into the fitting function for support vector regression calculation, and the water body to be tested is obtained Turbidity value.

Further, the signal conditioning circuit includes a first programmable gain amplifier circuit, a second programmable gain amplifier circuit, a multiplex switch, a first amplifier circuit, a second amplifier circuit, a first bandpass filter, a second bandpass filter pass filter, a first effective value conversion circuit, a second effective value conversion circuit, a first AD conversion circuit, and a second AD conversion circuit, the first receiver is connected to the first programmable gain amplifier circuit, and the first A programmable gain amplification circuit is connected to the multiplexer, the multiplexer is connected to the first amplifying circuit, the first amplifying circuit is connected to the first bandpass filter, and the first bandpass The filter is connected to the first effective value conversion circuit, the first effective value conversion circuit is connected to the first AD conversion circuit, and the first AD conversion circuit is connected to the core board control module; the second receiver Connect the second programmable gain amplifier circuit, the second programmable gain amplifier circuit is connected to the multiplexer switch, the multiplexer switch is connected to the second amplifier circuit, and the second amplifier circuit is connected to the The second bandpass filter, the second bandpass filter is connected to the second effective value conversion circuit, the second effective value conversion circuit is connected to the second AD conversion circuit, and the second AD conversion circuit The core board control module is connected, and the core board control module respectively controls the first programmable gain amplifier circuit, the second programmable gain amplifier circuit and the multiplexer switch.

Further, both the first receiver and the second receiver are OPT101 modules, and the OPT101 module is used for optical signal reception and IV conversion.

Further, the fitting function is the data collected by the control module of the core board according to the international standard solutions with different turbidity values, and the temperature-compensated first transmission voltage signal and the second transmission voltage signal by using the support vector machine , the first scattering voltage signal, the second scattering voltage signal, the first ratio, and the second ratio are trained to establish a model.

Further, the core board control module drives the first emitter and the second emitter to emit optical signals in time-division, specifically, the core board control module drives the first emitter within the first 0.5 seconds. The emitter emits an optical signal, and the second emitter is driven to emit an optical signal within a second 0.5 second.

Further, both the first programmable gain amplifier circuit and the second programmable gain amplifier circuit adopt PGA103 chip, and the first programmable gain amplifier circuit and the second programmable gain amplifier circuit are capable of scatter voltage signal The gain is 100, and the gain of the first programmable gain amplifying circuit and the second programmable gain amplifying circuit is 1 for the transmission voltage signal.

Further, it includes an SD card storage module and a Bluetooth module, the SD card storage module and the Bluetooth module are connected to the core board control module, the SD card storage module is used for system storage and retrieval of detection data, and the The core board control module is wirelessly connected to the intelligent terminal through the Bluetooth module and transmits detection data to the intelligent terminal. The intelligent terminal is provided with a human-computer interaction APP, and the APP is used to control data transmission and view the detection data in real time.

The beneficial effects brought by the technical solution provided by the embodiments of the present invention are: a portable optical fiber turbidity detection device of the present invention, when detecting the turbidity of water body, the probe is directly immersed in the water body, and the core board control module controls the emission module Transmit optical signal, the optical signal sent by the transmitting module is transmitted to the interface by the plastic optical fiber, and then injected into the water body, the optical signal receiving module receives the optical signal transmitted and scattered by the water body, and adjusts the received optical signal The optical signal is sent to the core board control module for data processing. Data processing includes temperature compensation and support vector regression (SVR), thereby obtaining the turbidity data of the test water body. The core board control module is connected with an SD card storage module module. The detection data is stored and taken out by the system; the core board control module is wirelessly connected to the smart terminal through the Bluetooth module, and can transmit the detection data to the smart terminal. The smart terminal is equipped with a supporting human-computer interaction APP, and the APP is used to control data transmission And view the detection data of the device in real time. The whole device is small in size, convenient and quick to use, stable in circuit operation, and accurate in detection data, which solves the problems of the existing turbidity detection devices that are not easy to carry, high in cost, and low in accuracy.

Description of drawings

Fig. 1 is a working principle block diagram of a portable optical fiber turbidity detection device of the present invention.

FIG. 2 is a schematic diagram of the connection between the probe 3 and the transmitting module 2 and receiving module 4 in FIG. 1 .

FIG. 3 is a block diagram of the working principle of the receiving module 4 in FIG. 1 .

In the figure: 1-core board control module, 2-transmission module, 21-first transmitter, 22-second transmitter, 3-probe, 31-first interface, 32-second interface, 33-third interface , 34-the fourth interface, 35-3D printing ring, 36-optical fiber, 4-receiving module, 41-the first receiver, 41a-the first programmable gain amplifier circuit, 41b-the first amplifier circuit, 41c-the first Band-pass filter, 41d-the first effective value conversion circuit, 41e-the first AD conversion circuit, 42-the second receiver, 42a-the second programmable gain amplifier circuit, 42b-the second amplifier circuit, 42c-the first Two band-pass filters, 42d-the second RMS conversion circuit, 42e-the second AD conversion circuit, 43-multiplexing switch, 5-power supply module, 6-temperature sensor, 7-intelligent terminal, 8-Bluetooth module, 9-SD card storage module.

Detailed ways

In order to make the purpose, technical solution and advantages of the present invention clearer, the embodiments of the present invention will be further described below in conjunction with the accompanying drawings.

Please refer to Figure 1 and Figure 2, the embodiment of the present invention provides a portable optical fiber turbidity detection device, including a core board control module 1, a transmitting module 2, a probe 3, a receiving module 4, a power module 5, a temperature sensor 6, Smart terminal 7, bluetooth module 8 and SD card storage module 9.

The emission module 2 includes a first emitter 21 and a second emitter 22, the first emitter 21 and the second emitter 22 are near-infrared light emitting tubes of 850nm, and the first emitter 21 and the second transmitter 22 are respectively connected to the core board control module 1, the main control chip adopted by the core board control module 1 is STM32F103RCT6, and the first transmitter 21 and the second transmitter 22 are all composed of The control module 1 of the core board drives and emits optical signals in time division. In this embodiment, the core board control module 1 drives the first emitter 21 and the second emitter 22 to emit light signals. In the previous 0.5 seconds, the core board control module 1 drives the The first emitter 21 emits an optical signal, and within the next 0.5 seconds, the core board control module 1 drives the second emitter 22 to emit an optical signal. This time-sharing driving is to avoid the interference of the light source signal, and two light sources are used. The signal is detected to increase the accuracy of the data. At the same time, the temperature compensation is used to reduce the influence of the ambient temperature on the detection device and improve the anti-interference ability.

Please refer to Fig. 1, Fig. 2 and Fig. 3, described receiving module 4 comprises first receiver 41, second receiver 42 and signal conditioning circuit, and described signal conditioning circuit comprises first programmable gain amplifying circuit 41a, second Programmable gain amplifying circuit 42a, multiplex switch 43, first amplifying circuit 41b, second amplifying circuit 42b, first bandpass filter 41c, second bandpass filter 42c, first effective value conversion circuit 41d, the second Two effective value conversion circuits 42d, a first AD conversion circuit 41e and a second AD conversion circuit 42e, the first receiver 41 is connected to the first programmable gain amplifier circuit 41a, and the first programmable gain amplifier circuit 41a Connect the multiplex switch 43, the multiplex switch 43 is connected to the first amplifying circuit 41b, the first amplifying circuit 41b is connected to the first bandpass filter 41c, and the first bandpass filter The device 41c is connected to the first effective value conversion circuit 41d, the first effective value conversion circuit 41d is connected to the first AD conversion circuit 41e, and the first AD conversion circuit 41e is connected to the core board control module 1; The second receiver 42 is connected to the second programmable gain amplifying circuit 42a, the second programmable gain amplifying circuit 42a is connected to the multiplexer 43, and the multiplexer 43 is connected to the second amplifying circuit 42b, the second amplifying circuit 42b is connected to the second bandpass filter 42c, the second bandpass filter 42c is connected to the second effective value conversion circuit 42d, and the second effective value conversion circuit 42d The second AD conversion circuit 42e is connected, and the second AD conversion circuit 42e is connected to the core board control module 1 .

Both the first optical signal receiver 41 and the second optical signal receiver 42 are OPT101 modules, the OPT101 module is used for optical signal reception and IV conversion, the first optical signal receiver 41 and the The second optical signal receivers 42 are used to convert the received optical signal into a current signal first, and then convert the current signal into a voltage signal by IV conversion.

The first receiver 41 is used to receive the first transmitted light signal transmitted by the first transmitter 21 straight through the water body to be measured in the previous 0.5s and the vertical light signal sent by the second transmitter 22 in the next 0.5s. The second scattered light signal transmitted through the water body to be measured in the transmission direction is converted into a first transmission voltage signal and a second scattering voltage signal, and at the same time, the first transmission voltage signal and the second scattering voltage signal are transmitted to the first possible Programming gain amplification circuit 41a, the second receiver 42 is used to receive the second transmitted light signal of the second transmitter 22 linearly transmitted through the water body to be measured in the next 0.5s and the first transmitted light signal in the previous 0.5s. Transmitter 21 transmits the first scattered light signal that passes through the water body to be measured perpendicular to the transmission direction and converts it into a second transmission voltage signal and a first scattering voltage signal, and simultaneously transmits the second transmission voltage signal and the first scattering voltage signal To the second programmable gain amplifying circuit 42a, the first programmable gain amplifying circuit 41a and the second programmable gain amplifying circuit 42a are used to convert the received second scatter voltage signal and the first scatter voltage signal amplified and sent to the multi-way switch 43, the multi-way switch 43 is used to separately receive the first transmission voltage signal, the first scattering signal amplified by the second programmable gain amplification circuit 42a The voltage signal and the second transmission voltage signal, and the second scattered voltage signal amplified by the first programmable gain amplifier circuit 41a are time-divisionally output, and then transmitted to the first amplifier circuit 41b and the second amplifier circuit 42b, The first band-pass filter 41c and the second band-pass filter 42c are used to filter the voltage signal to filter out noises other than 1KHz, the first effective value conversion circuit 41d and the second The effective value conversion circuit 42d is used to take the effective value of the filtered voltage signal and output it to the first AD conversion circuit 41e and the second AD conversion circuit 42e, and the first AD conversion circuit 41e and the second AD conversion circuit 41e The conversion circuit 42e is used to convert the analog signals input by the first effective value conversion circuit 41d and the second effective value conversion circuit 42d into digital signals, and send them to the core board control module 1 .

The probe 3 is provided with a 3D printing ring 35, and the 3D printing ring 35 is evenly provided with a first interface 31, a second interface 32, a third interface 33 and a fourth interface 34, and the first interface 31 , the second interface 32, the third interface 33 and the fourth interface 34 are respectively provided with a plastic optical fiber 36, and the first transmitter 21 is connected to the first interface 32 through a plastic optical fiber 36, The second transmitter 22 is connected to the second interface 33 through a plastic optical fiber 36, the first receiver 41 is connected to the third interface 34 through a plastic optical fiber 36, and the second receiver 42 is connected to the fourth interface 35 through a plastic optical fiber 36 .

The temperature sensor 6 is a DS18B20 digital temperature sensor, and the temperature sensor 6 is used to detect the temperature of the water body to be measured and transmit the temperature data to the core board control module 1 .

The core board control module 1 calculates a first ratio for the ratio of the first transmission voltage signal and the first scattering voltage signal, and the core board control module 1 calculates a second ratio for the ratio of the second transmission voltage signal and the second scattering voltage signal. Ratio, and the temperature compensation of the first transmission voltage signal, the second transmission voltage signal, the first scattering voltage signal, the second scattering voltage signal, the first ratio, and the second ratio are substituted into the fitting function for support vector regression calculation, The turbidity value of the water body to be measured is obtained, and the fitting function is the data collected by the core board control module 1 according to the detection of international standard solutions with different turbidity values, and the first transmission after temperature compensation is utilized by a support vector machine. The voltage signal, the second transmission voltage signal, the first scattering voltage signal, the second scattering voltage signal, the first ratio, and the second ratio are trained to establish a model.

Both the core board control module 1 and the receiving module 4 are connected to a power module 5, and the power module 5 is a rechargeable 12V lithium battery.

The core board control module 1 is also connected to the bluetooth module 8 and the SD card storage module 9 respectively, and the bluetooth module 8 is a master-slave integrated bluetooth serial port module for transmitting the turbidity data of the water body to be measured to the intelligent terminal 7, The bluetooth module 8 is wirelessly connected with the intelligent terminal 7, and transmits the turbidity data of the water body to be measured to the intelligent terminal 7, the intelligent terminal 7 is a mobile phone or a computer, and the intelligent terminal 7 is provided with a human-computer interaction APP , the APP is used to control the bluetooth module 8 and display the turbidity data of the water body to be tested, and the SD card storage module 9 is used for system storage of detection data including turbidity data.

In this article, the orientation words such as front, rear, upper, and lower involved are defined by the parts in the drawings and the positions between the parts in the drawings, just for the clarity and convenience of expressing the technical solution. It should be understood that the use of the location words should not limit the scope of protection claimed in this application.

In the case of no conflict, the above-mentioned embodiments and features in the embodiments herein may be combined with each other.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection of the present invention. within range.

Claims (7)

1. a kind of portable fiber-optic turbidity detection device, it is characterised in that: including core board control module, transmitting module, probe, Receiving module and temperature sensor, the transmitting module include first transmitter and second transmitter, and the receiving module includes First receiver, second receiver and signal conditioning circuit, the probe is equipped with 3D printing annulus, on the 3D printing annulus It is uniformly provided with first interface, second interface, third interface and the 4th interface, the first interface, the second interface, described Insertion is connected with a plastic optical fiber on three interfaces and the 4th interface, and the first transmitter passes through a plastic optical fiber The first interface is connected, the second transmitter connects the second interface by a plastic optical fiber, and described first connects It receives device and the third interface is connected by a plastic optical fiber, the second receiver connects institute by a plastic optical fiber The 4th interface is stated, first receiver and the second receiver are all connected with the signal conditioning circuit, the signal condition Circuit and the temperature sensor are all connected with the core board control module, and the core board control module is separately connected described One transmitter and the second transmitter, first transmitter described in the core board control module Time-sharing control and second hair Emitter emits optical signal, and first receiver is used to receive the first optical signal transmissive that the first transmitter issues and described Second scattered light signal of second transmitter sending simultaneously converts the first transmissive voltage signal and second for received signal Voltage signal is scattered, while the first transmissive voltage signal and the second scattering voltage signal are transmitted to the signal conditioning circuit, The second receiver is used to receive the second optical signal transmissive that the second transmitter issues and the first transmitter issues The first scattered light signal and by received signal be converted into the second transmissive voltage signal and first scattering voltage signal, together When by the second transmissive voltage signal and first scattering voltage signal be transmitted to the signal conditioning circuit, the signal conditioning circuit It is described for improving the two transmissive voltage signals received and two scattering voltage signals and being transmitted to the core board control module Temperature sensor is for detecting water temperature to be measured and transmitting the temperature data to the core board control module, the core board Control module is to the first transmissive voltage signal, the second transmissive voltage signal, the first scattering voltage signal, the second scattering voltage signal Voltage signal after conditioning carries out temperature-compensating, and the core board control module makees radiometer to the voltage signal after temperature-compensating It calculates, calculating the first transmissive voltage signal and the first scattering voltage signal ratio is the first ratio, calculates the second transmissive voltage signal It is the second ratio with the second scattering voltage signal ratio, and by the first transmissive voltage signal, the second transmissive voltage after temperature-compensating Signal, the first scattering voltage signal, the second scattering voltage signal, the first ratio and the second ratio are substituted into fitting function and are supported Vector regression calculates, and obtains the turbidity value of water body to be measured.

2. a kind of portable fiber-optic turbidity detection device as described in claim 1, it is characterised in that: the signal conditioning circuit Including the first Programmable Gain Amplifier Circuit, the second Programmable Gain Amplifier Circuit, multicircuit switch, the first amplifying circuit, Second amplifying circuit, the first bandpass filter, the second bandpass filter, the first RMS-DC converter circuit, the second RMS-DC converter Circuit, the first A/D converter circuit, the second A/D converter circuit, first receiver connect the first programmable automation controller electricity Road, first Programmable Gain Amplifier Circuit connect the multicircuit switch, the multicircuit switch connection described the One amplifying circuit, first amplifying circuit connect first bandpass filter, described in the first bandpass filter connection First RMS-DC converter circuit, the first A/D converter circuit described in the first RMS-DC converter circuit connection, the first AD turn Change core board control module described in circuit connection；The second receiver connects second Programmable Gain Amplifier Circuit, institute It states the second Programmable Gain Amplifier Circuit and connects the multicircuit switch, multicircuit switch connection second amplification Circuit, second amplifying circuit connect second bandpass filter, and the second bandpass filter connection described second has Valid value conversion circuit, the second A/D converter circuit described in the second RMS-DC converter circuit connection, second A/D converter circuit Connect the core board control module, the core board control module control respectively first Programmable Gain Amplifier Circuit, Second Programmable Gain Amplifier Circuit and the multicircuit switch.

3. a kind of portable fiber-optic turbidity detection device as described in claim 1, it is characterised in that: first receiver and Second receiver is OPT101 module, reception and IV conversion of the OPT101 module for optical signal.

4. a kind of portable fiber-optic turbidity detection device as described in claim 1, it is characterised in that: the fitting function is institute Core board control module is stated according to the collected data of international standard solution for detecting different turbidity values, utilizes support vector machines pair The first transmissive voltage signal, the second transmissive voltage signal, the first scattering voltage signal, the second scattering voltage letter after temperature-compensating Number, the first ratio, the second ratio is trained to establish model and obtain.

5. a kind of portable fiber-optic turbidity detection device as described in claim 1, it is characterised in that: the core board controls mould Block timesharing drives the first transmitter and the second transmitter to emit optical signal, specifically, the core board control module The first transmitter transmitting optical signal is driven in 0.5 second at first, drives the second transmitter in 0.5 second at second Emit optical signal.

6. a kind of portable fiber-optic turbidity detection device as claimed in claim 2, it is characterised in that: the described first programmable increasing Beneficial amplifying circuit and second Programmable Gain Amplifier Circuit are all made of PGA103 chip, first programmable automation controller Circuit and second Programmable Gain Amplifier Circuit are 100 to the gain of scattering voltage signal, first programmable-gain Amplifying circuit and second Programmable Gain Amplifier Circuit are 1 to the gain of transmissive voltage signal.

7. a kind of portable fiber-optic turbidity detection device as described in claim 1, it is characterised in that: including SD card memory module And bluetooth module, the SD card memory module and the bluetooth module are all connected with the core board control module, the SD card is deposited Module is stored up for the system storage of detection data and is taken out, the core board control module is wirelessly connected by the bluetooth module Intelligent terminal simultaneously transmits detection data to the intelligent terminal, and the intelligent terminal is equipped with human-computer interaction APP, and the APP is used for Control detection data described in data transmission and real time inspection.