CN109060888A

CN109060888A - A kind of sampling method and device

Info

Publication number: CN109060888A
Application number: CN201810798642.9A
Authority: CN
Inventors: 刁心玺; 周潇; 胡淼龙
Original assignee: ZHEJIANG WINS WIRELESS NETWORK TECHNOLOGY Co Ltd
Current assignee: ZHEJIANG WINS WIRELESS NETWORK TECHNOLOGY Co Ltd
Priority date: 2018-07-19
Filing date: 2018-07-19
Publication date: 2018-12-21

Abstract

The present invention provides a kind of sampling method and device, which comprises carries out water quality on-line checking, or receives water body sampling instruction from network side；Sampling module is controlled according to water quality on-line checking result or water body sampling instruction；Sampling is sent to network side to complete or sample unsuccessfully to indicate information.Can review on-line monitoring as a result, and review the time it is flexible, it is not necessary to immediately enter monitoring field, reduce operator monitoring amount, have practicability.

Description

Sampling method and device

Technical Field

The invention relates to the field of inspection and detection, in particular to a sampling method and a sampling device.

Background

The water quality on-line monitoring system uses a line analysis instrument and a laboratory analysis instrument to detect water quality, and realizes on-line automatic monitoring of samples by collecting samples with representativeness, timeliness and reliability. The automatic monitoring system generally comprises a sampling system, a preprocessing system, a data acquisition and control system, an online monitoring and analysis instrument, a data processing and transmission system and a remote data management center, wherein the subsystems form a system and cooperate with each other to complete the continuous and reliable operation of the whole online automatic monitoring system.

Currently, common manufacturers of online water quality analyzers include: HACH, SERES, Germany WTW, E + H, KUNTZE, Japan Shimadzu, Horiba, Austrian SCAN, etc., USA. The following types of online water quality analyzers are classified according to measured parameters: PH, dissolved oxygen, conductivity, turbidity, chlorophyll, cyanobacteria, permanganate index, chemical oxygen demand, biological oxygen demand, ammonia nitrogen, nitrate nitrogen, nitrite nitrogen, total phosphorus, phosphate, total nitrogen, and the like.

Since 1998, 100 national surface water quality automatic monitoring stations have been established in 10 key drainage basins of seven water systems in China, and more than 400 local surface water quality automatic monitoring stations are established in each place according to the requirement of environmental management, so that the automatic water quality monitoring weekly report is realized. The current automatic water quality monitoring device can not meet the requirement of rapidly developed water quality monitoring in manufacturing, so that the domestic automatic monitoring device has wide development prospect and potential sale market.

The multi-parameter water quality on-line automatic monitoring system is suitable for: monitoring a water source area, an environment-friendly monitoring station, a municipal water treatment process, municipal pipe network water quality supervision and rural tap water monitoring; the method comprises the following fields of circulating cooling water, swimming pool water operation management, industrial water source recycling, industrial aquaculture and the like.

The software architecture of the water quality on-line monitoring system can be expanded to hundreds of monitoring nodes, and each node can be provided with a plurality of sensors. According to the actual operation condition, the parameters of the tested water quality can be increased, such as: the user can select conventional parameters of the water, such as turbidity, conductivity, oxidation-reduction potential, total organic carbon, ammonia nitrogen, COD, various organics, free chlorine, total fluorine, PH, flow, pressure, temperature, etc., to be monitored by conventional sensors, while selectively monitoring various chemical contaminants based on local water resource conditions and past pollution events.

The water quality on-line monitoring system can quickly and accurately extract important water quality data and present the data in a clear report format. The report of one standard includes the following information: water general indicator, maximum, minimum, average, system status.

The water quality on-line analysis instrument is generally divided into an electrode method and a photometric method according to the measurement mode.

The following types of online water quality analyzers are classified according to measured parameters:

the water intaking system is designed mainly aiming at satisfying representativeness, reliability and continuity of water sample, and the main components of the system are as follows: the water sampling device comprises a water sampling head, a water sampling pump, a water sample conveying pipeline and a flow velocity and flow regulation part. The division according to the water intaking mode mainly includes two types, namely a direct intaking type and a floating cylinder type, wherein the direct intaking type is mainly used for environments with small water level changes, such as sewage plants, pollution sources and tap water culvert pipes for intaking water, and the floating cylinder type is mainly used for environments with large water level changes, such as surface water.

The pretreatment system of the water quality on-line monitoring system is mainly used for eliminating factors which interfere with the analysis of the instrument and influence the use of the instrument and cannot lose the representativeness of a water sample. The pretreatment means generally includes natural sedimentation, physical filtration, permeation and the like. The level of pretreatment is generally determined by the purity of the water sample. Some analytical instruments have been designed with sample pretreatment taken into consideration, and need to be used in combination with the system during system integration.

The water quality on-line monitoring system mainly comprises a PLC, an on-site industrial personal computer, a central station computer, a transmitter, an actuating mechanism and the like, and has the following functions:

(1) controlling the automatic operation of the whole online monitoring system, wherein the automatic operation is mainly completed after a program is written in by a PLC;

(2) the data analyzed by the instrument is collected, stored and transmitted, and the data is mainly completed by the cooperation of the field industrial personal computer and the data collecting and transmitting module.

The integrated auxiliary system of the water quality on-line monitoring system is mainly used for guaranteeing the continuous and stable operation of the on-line monitoring system, and the integrated auxiliary system needs to be adjusted correspondingly according to the change of the field condition. In general, the following aspects need to be noted:

(1) cleaning a pipeline: because the remaining dirt in the pipeline and therefore the algae that propagates can cause the pollution to the water sample, so need carry out regularly quantitative washing to the pipeline, the abluent mode and content are various, and the target is in order to guarantee authenticity and the representativeness of water sample.

(2) And (3) electric power guarantee: the stability of the electric power is directly related to the accuracy and continuity of the instrument analysis, so that a stable alternating current power grid is selected as far as possible for access; secondly, before the alternating current enters the automatic monitoring system, the current needs to be rectified again so as to deal with the occurrence of sudden current instability; finally, if necessary, a back-up power supply may be provided to allow for proper operation of the on-line monitoring system in the event of a power outage.

(3) Lightning stroke prevention: the lightning protection is mainly divided into station room lightning protection, power supply lightning protection and communication lightning protection, and when the station room is struck by lightning, the lightning protection device is firstly punctured by current so as to achieve the purpose of protecting instruments and system equipment. This is particularly important in areas with high thunderstorms, where workers need to check the state of the lightning protection device as soon as possible after a thunderstorm occurs, and need to replace the lightning protection device in time if the lightning protection device is damaged.

(4) Temperature and humidity adjustment: the proper temperature and humidity are also important for the stable operation of the instrument, and the part of the function is mainly realized by the air conditioning and dehumidifying equipment.

The probes of the existing electrode type multi-parameter water quality monitor (such as DCT-MWQ-5100/5101) can be freely combined and independently replaced, and can be plugged and used and remotely controlled; and (3) expandability: monitoring multiple factors simultaneously, and installing 2-12 sensors; various applications: long-term online work, on-site rapid determination, emergency monitoring, underground water monitoring and self-contained batteries; firm shell: the POM material (acetaldehyde polymer) resists seawater corrosion and can normally work under 200 meters of water; the structure is compact: the diameter is 76mm, and the device can be installed in occasions with smaller size.

The existing water quality five-parameter sensor adopts advanced modular design and advanced digital communication technology, and consists of a universal controller and sensors, wherein one universal controller can be simultaneously connected with five sensors of pH, dissolved oxygen, conductivity, water temperature and turbidity, and can realize on-screen display.Wherein the turbidity sensor is provided with an ultrasonic cleaning module insideAnd the stability and accuracy of long-time work are ensured.

In the field of patent applications, the following conductivity measurement techniques have emerged:

the utility model has the application number of CN201721555968.6, the invention name is "a conductivity measuring instrument", including conductivity sensor, still include the excitation signal generating circuit who provides the excitation source for conductivity sensor, the amplification shaping circuit that amplifies the shaping is carried out to conductivity sensor's output signal, direct current converting circuit, analog-to-digital conversion circuit and controller, excitation signal generating circuit includes square wave excitation source and filter circuit, square wave excitation source, filter circuit, conductivity sensor, the amplification shaping circuit, direct current converting circuit, analog-to-digital conversion circuit and controller connect gradually, the controller is connected with square wave excitation source and provides clock signal for square wave excitation source, conductivity measuring instrument still includes temperature compensation circuit, temperature compensation circuit passes through analog-to-digital conversion circuit and is connected with the controller.

The invention has the application number of CN201710270275.0, and is named as a measuring device and a method for detecting the conductivity and resistivity of water, and the device comprises a measuring circuit, a subtraction circuit, an AD conversion circuit and a main chip which are connected in sequence; the measuring circuit is connected with the main chip; the method comprises the following steps: the measuring circuit is excited by positive pulse square waves from the main chip, different voltages are loaded to two ends of the electrode, so that alternating forward and reverse currents are generated in water, and the alternating forward and reverse currents are amplified and detected to obtain signal voltages V1 and V2; the subtracting circuit subtracts the signal voltages V1 and V2 to obtain a measurement signal Vout; the AD conversion circuit performs AD conversion on the measurement signal Vout; the main chip calculates the conductivity or resistivity of the water from the measurement signal Vout after AD conversion. The invention adopts positive pulse square wave to excite the solution to be detected, and the excitation amplifying circuit is arranged, so that the conductivity cell has positive and negative direction current flowing when the positive pulse square wave is excited, and the polarization effect is resisted.

The application number is CN201611172938.7, the invention name is a water resource conductivity measuring circuit with temperature compensation, a processor module is in signal connection with an excitation source circuit, the excitation source circuit is in signal connection with a conductivity probe, the conductivity probe is in signal connection with a range switching circuit, the range switching circuit is in signal connection with a true effective value conversion circuit, the true effective value conversion circuit is in signal connection with an analog-to-digital conversion circuit, the analog-to-digital conversion circuit is in signal connection with the processor module, a temperature value probe is in signal connection with a signal conditioning circuit, the signal conditioning circuit is in signal connection with the analog-to-digital conversion circuit, and a power supply module is connected with power supplies of other modules. The invention has the functions and characteristics of automatic temperature compensation, manual range adjustment, high-precision analog acquisition and the like.

The invention is a conductivity measuring method, a circuit and a conductivity measuring instrument, with application number CN201610583932.2, and the invention name "the conductivity measuring method comprises the following steps: generating an alternating-current square wave signal; amplifying the alternating square wave signal; connecting the amplified square wave signal with one end of an electrode through a lead wire to generate an alternating electric field in an electrolyte solution; detecting weak alternating current signals generated at two ends of the electrodes of the conductivity meter in the alternating electric field by the other end of the electrode; the weak alternating current signal is converted into an alternating voltage signal; rectifying and filtering to obtain a stable direct current voltage signal; the dc voltage signal is converted to a corresponding conductivity display.

The application number is CN201520679587.3, the invention name is "a high-precision conductivity measuring system", disclose a high-precision conductivity measuring system, including the quadrupole conductivity sensor used for measuring the conductivity of liquid medium, the test voltage generating module is connected with the quadrupole conductivity sensor, and produce the test voltage signal to transmit to the test polar plate and produce the reference voltage signal to transmit to the reference polar plate under the control of the control module; the current sampling module is used for sampling a current signal generated by the quadrupole conductivity sensor, the current signal is amplified by the pre-amplification module and the secondary amplification module and then output to the control module, and the control module obtains a conductivity value through calculation and displays data information through the display module. Adopt the technical scheme of the utility model, through multirange automatic switch-over, can select suitable range of measurement according to the test environment of difference, adopt quadrupole conductivity sensor simultaneously, can realize automatic compensation according to reference electrode automatically regulated test voltage to measurement accuracy is provided.

The liquid conductivity measuring electrode is provided with application number CN201410828826.7 and is named as a liquid conductivity measuring electrode with a micro water pump, and consists of two electrodes, namely a first electrode, a second electrode and the micro water pump; the two electrodes, namely the first electrode and the second electrode, are cylindrical straight cylinders with unequal diameters and equal heights, the first electrode is a cylindrical straight cylinder with a bottom surface, and the second electrode is a cylindrical straight cylinder without a bottom surface; the second electrode is coaxial with the first electrode and is arranged in an end face alignment manner to form two aligned electrode end faces, wherein the end face corresponding to the bottom face of the first electrode is called a first aligned electrode end face, the other end face is called a second aligned electrode end face, the second electrode surrounds the first electrode, a uniform gap is reserved between the cylindrical side walls of the two electrodes, and the first aligned electrode end face is coaxially connected with the water outlet end of the micro water pump. The innovation point of the technical scheme is that the surface of the electrode can not be gathered and the ions are attached to form a stable double electric layer, so that the polarization of the electrode is avoided.

The method for measuring the conductivity, which is provided by the invention name of "method for measuring the conductivity and system for measuring the conductivity using the method", and which is under the application number CN201310560258.2, comprises the following steps: acquiring a conductivity cell constant of a conductivity cell by using a conductivity standard solution; injecting a solution desired to be measured into the conductivity cell and applying a predetermined direct voltage to electrodes provided in the conductivity cell in such a manner that the predetermined direct voltage is changed in stages at respective preset times t; obtaining the resistance of the solution as a slope from a linear relationship between the voltage and a peak current, wherein the peak current is measured for each voltage; and calculating the conductivity of the solution using the conductivity cell constant and the resistance of the solution.

Although the existing conductivity measuring device can keep better performance in a light polluted water area, in a heavy polluted water area, long-time online detection can cause the defects that a conductivity measuring electrode is easy to corrode, the conductivity measuring precision is influenced by the surface sediments of the electrode, and the water temperature measurement increases the complexity of a watertight structure, and particularly, the existing conductivity measuring device cannot automatically sample and store over-standard sewage and cannot perform retest on online monitoring results.

The invention provides a liquid sampling container, which is used for overcoming at least one of the defects that the prior conductivity measurement technology can not automatically sample and store over-standard sewage and can not re-test an online monitoring result.

Disclosure of Invention

The invention provides a sampling method and a sampling device, which are used for overcoming at least one of the defects that the existing conductivity measurement technology cannot automatically sample and store the overproof sewage and cannot re-test the online monitoring result.

The invention provides a sampling method, which comprises the following steps:

step S110, carrying out water quality on-line detection, or receiving a water body sampling instruction from a network side;

step S120, controlling a sampling module according to a water quality online detection result or a water body sampling instruction;

step S130, sending sampling completion or sampling failure indication information to the network side.

The invention provides a sampling device, which comprises the following modules:

a water quality detection module 230, a communication module 220, a sampling module 240, and a sampling control module 210; wherein,

the water quality detection module 230 is used for online detection of water quality and comprises a detection electrode and a detection circuit;

the communication module 220 is used for sending sampling completion indication information or sampling failure indication information to the network side or receiving a water body sampling instruction from the network side, and comprises a wired transmission sub-module or a wireless transmission sub-module;

the sampling module 240 is used for sampling the water body and comprises a water pump and a water body storage container;

the sampling control module 210 controls the sampling module according to the water quality detection result or the water sampling instruction, and comprises a water quality detection result or water sampling instruction processing module.

The method and the device provided by the embodiment of the invention can overcome at least one of the defects that the existing conductance measurement technology cannot automatically sample and store the overproof sewage and cannot re-test the online monitoring result. Low cost and practicability.

Additional features and advantages of the invention will be set forth in the description which follows.

Drawings

FIG. 1 is a flow chart of a sampling method according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a sampling device according to an embodiment of the present invention;

fig. 3 is a schematic composition diagram of a liquid conductivity measurement module according to an embodiment of the present invention.

Examples of the invention

The invention provides a device for sampling monitored liquid at a monitoring site and for subsequent detection or assay of the sample.

The device provided by the invention comprises a liquid storage cavity and a memory capable of storing information such as field measurement data, sampling time, sampling place and the like; the storage of the information can avoid confusion among sample liquids obtained from different fields, and can conveniently compare the field initial detection result with the subsequent detection or assay result of the sample.

By sampling the monitored liquid on site, the liquid can be sampled and stored after the online detection device arranged on site detects the liquid abnormality, so as to prepare for subsequent offline recheck, and workers can arrive at the scene of the incident without being required. The liquid state monitoring mode for sampling and standby inspection can avoid the sudden attendance of workers in sewage monitoring and avoid the day and night duty of the workers.

In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that the embodiments and features of the embodiments in the present application may be arbitrarily combined with each other without conflict.

The following describes an example and a system of the position detection method provided by the present invention with reference to the drawings.

Example A sampling method

Referring to fig. 1, an embodiment of a sampling method provided by the present invention includes the following steps:

Specifically, the online detection of water quality refers to arranging a water quality detection electrode or a photometric module on the site of the detected water body.

The method of the present embodiment, wherein,

the online detection of water quality comprises the following steps:

acquiring initial measurement parameters of water quality;

determining water quality on-line detection parameters by using the initial water quality measurement parameters; or

Sending the initial water quality measurement parameters to a network side, and determining water quality on-line detection parameters by the network side;

the water quality initial measurement parameters comprise initial measurement parameters used for calculating at least one of the following water quality parameters:

PH, dissolved oxygen, conductivity, turbidity, chlorophyll, cyanobacteria, permanganate index, chemical oxygen demand, biological oxygen demand, ammonia nitrogen, nitrate nitrogen, nitrite nitrogen, total phosphorus, phosphate, total nitrogen, and total nitrogen.

Specifically, the water quality initial measurement parameter is an electrical parameter obtained by direct measurement using a water quality measurement module or a module combination deployed on a detected water body site, for example, in order to measure the conductivity, a sine wave signal is applied to a capacitance electrode placed in a water body and the amplitude of the sine wave signal subjected to water body partial pressure is measured, the amplitude of the signal is the water quality initial measurement parameter, the resistance value of the water body calculated through voltage is a derived parameter of the water quality initial measurement parameter, and the conductivity of the water body calculated through the resistance value is a derived parameter of the initial measurement parameter; specifically, the water quality on-line detection parameter is a derived parameter of a water quality initial measurement parameter.

Specifically, the measured value of the water temperature is an initial water quality measurement parameter, the water quality parameter is normalized by using the measured value of the water temperature to obtain a water quality parameter without temperature influence, and the water quality parameter without temperature influence is also a derived parameter of the initial water quality measurement parameter.

Different water quality parameters need to adopt different online measurement methods, and generally, parameters such as pH value, dissolved oxygen, conductivity, turbidity, chlorophyll, blue algae, chemical oxygen demand, biological oxygen demand, ammonia nitrogen, nitrate nitrogen and nitrite nitrogen are measured by using an electrode method; permanganate index, total phosphorus, phosphate and total nitrogen were measured photometrically.

The method of the present embodiment, wherein,

the water quality initial measurement parameters specifically comprise: an initial measured parameter for calculating conductivity.

The method of the present embodiment, wherein,

the receiving of the water sampling instruction from the network side comprises:

and receiving a water body sampling instruction from a communication node or a water quality monitoring server on the network side.

The communication node or the water quality monitoring server at the slave network side receives a water body sampling instruction, and automatic triggering or manual triggering of a background on site sampling actions is realized;

generally, the initial water quality measurement parameters are further processed through the background to obtain derived parameters of the initial water quality measurement parameters, and the derived parameters can obtain more accurate physical results than the initial water quality measurement parameters are processed on site, so that a water body sampling instruction is sent to a sampling device on the site of the monitored water body on the basis of further processing of the initial water quality measurement parameters through the background, and more accurate and more flexible sampling control results can be obtained.

The water body sampling instruction comprises at least one of the following information:

indicating information for water body sampling operation;

specific time information for water body sampling operation is carried out;

carrying out water body sampling operation mode information; and

and (4) carrying out water quality parameter threshold information of water body sampling.

Specifically, the indication information for performing the water body sampling operation includes indication information for starting a sampling module to work;

the specific time information for carrying out the water body sampling operation comprises specific time for carrying out sampling within one day or one week or time interval for carrying out sampling;

the information of the mode for carrying out the water body sampling operation comprises indication information of a water body sampling instruction triggering sampling action or an online measurement quantity triggering sampling action;

further, the indication information that the line measurement triggers the sampling action includes indication information that the sampling action is triggered by a water quality initial measurement parameter or a derived parameter of the water quality initial measurement parameter.

The water quality parameter threshold information for sampling the water body comprises a threshold of an initial measurement parameter or a threshold of a derived parameter of the initial water quality measurement parameter.

The method of the present embodiment, wherein,

according to online testing result of quality of water or water sampling instruction control sampling module, include:

and after the water quality on-line detection result exceeds the standard or after the water sampling starting information contained in the water sampling instruction is received, triggering the water sampling module to enter a water sampling process.

Specifically, the determining that the online detection result of the water quality exceeds the standard comprises:

comparing the current water quality measurement parameter with a preset parameter threshold, and judging that the water quality online detection result exceeds the standard when the current water quality measurement parameter is greater than the preset parameter threshold; otherwise, judging that the water quality on-line detection result does not exceed the standard.

And when the water quality on-line detection result is judged not to exceed the standard, the water body sampling module is not triggered to enter the water body sampling process.

The preset parameter threshold is an electric signal threshold corresponding to a specific water quality parameter;

specifically, the electric signal threshold corresponding to the specific water quality parameter includes a set value of at least one of resistance, conductance, voltage, current and frequency corresponding to the specific water quality parameter.

Specifically, in the conductivity measurement, the electrical signal threshold corresponding to a specific water quality parameter is a resistance value or a conductance value derived from a peak value of a sinusoidal signal.

In ammonia nitrogen electrode measurement, the relationship between ion concentration (activity) and electrode potential can be expressed by the following equation:

E=E0+(2.303RT/nF)×log(A)

where E is the total potential between the sensing electrode and the reference electrode (in mV) E0 is the characteristic constant for a particular ion-selective electrode/reference electrode pair. (it is the sum of all hydraulic contact potentials in the electrochemical cell);

2.303 is a factor by which natural numbers are converted to base 10 logarithms;

r is a gas parameter (8.314J/D/M);

t is the absolute temperature;

n is the ionic charge (including label) F is the Faraday constant (96500C/mol);

log (a) is the logarithm of the measured ion activity;

the factor 2.303RT/nF is known as the slope of the electrode (from the line plot of E versus log (a), i.e. the basis of the ion selective electrode correction graph). This should be a constant at ambient temperature that depends on the valence of the ion being measured. Under typical operating conditions, it can be found that this slope varies always between 50mV and 60mV for monovalent ions (25 mV to 30mV for divalent ions);

in the ammonia nitrogen electrode measurement, the predetermined parameter threshold is a predetermined value of the total potential E between the sensitive electrode and the reference electrode corresponding to the ammonia nitrogen ion concentration.

Specifically, the information for starting the water sampling included in the water sampling instruction includes at least one of indication information for starting the water sampling, time indication information for starting the water sampling, and mode indication information for starting the water sampling.

Specifically, triggering water sampling module gets into water sampling process, include:

sending an indication signal entering a sampling process to a water body sampling module; and

and receiving a sampling completion indication signal from the water body sampling module.

Further, after receiving the indication signal of entering the sampling process, the water body sampling module starts a water pump contained in the water body sampling module to extract sample water and injects the sample water into a water body sampling container; starting a sampling detection submodule contained in the water body sampling container to monitor the water level or water quantity in the water body sampling container;

and after the sampling detection sub-module monitors that the water level or the water quantity in the water body sampling container reaches a preset value, the sampling detection sub-module sends an indication signal of sampling completion to the sampling control module.

And if the indication signal of the sampling completion is not received from the water body sampling module within the specified time, judging that the water body sampling module is in failure or sampling fails.

The method of the present embodiment, wherein,

the sending of the sampling completion or sampling failure indication information to the network side includes:

sending sampling completion indication information to a communication node or a water quality monitoring server at a network side; or

And sending sampling failure indication information to a communication node or a water quality monitoring server on the network side.

Specifically, after the sampling control module receives the indication information that the water level or the water amount in the sampling container reaches a preset value, the sampling control module sends sampling completion indication information to a communication node or a water quality monitoring server on a network side through a wired or wireless channel; or

When the sampling control module does not receive the indication information that the water level or the water amount in the sampling container reaches the preset value within the specified time, the sampling control module sends sampling failure indication information to a communication node or a water quality monitoring server on the network side through a wired or wireless channel.

Taking the online measurement of the water conductivity parameter as an example, referring to fig. 3, the online measurement of the water conductivity parameter provided in this embodiment includes the following steps:

sending sine wave excitation signals with different frequencies to electrode a 310;

receiving coupled signals with different frequencies from electrode B311;

calculating voltage values corresponding to the coupling signals with different frequencies;

the electrical conductivity is calculated using the voltage values corresponding to the coupled signals at different frequencies.

Further, the sending of sine wave excitation signals with different frequencies to the electrode a includes:

the processor 320 controls the excitation signal generation module 330 to generate sine wave signals having first, second and third frequencies, which are sent to the electrode a310 through the excitation signal amplification module 331, and the electrode a310 injects the sine wave signals received by the electrode a into the liquid 300.

Specifically, the excitation signal generating module 330 includes a DDS (Direct Digital Synthesizer) sub-module, which generates sine wave signals of the first, second, and third frequencies, and the sine wave signals of the first, second, and third frequencies are amplified by the excitation signal amplifying module 331 and then sent to the electrode a 310.

Specifically, the excitation signal amplification module 331 performs power amplification on the sine wave signals of the first, second, and third frequencies.

Further, the processor 320 controls the excitation signal generation module 330 to generate the sine wave signals of the first, second and third frequencies, including the processor 320 controlling the excitation signal generation module 330 to generate the sine wave signals of the first, second and third frequencies in a time division manner; alternatively, the processor 320 controls the excitation signal generation module 330 to generate the sine wave signals of the first, second and third frequencies in a concurrent manner;

preferably, the processor 320 controls the excitation signal generation module 330 to generate the sine wave signals of the first, second and third frequencies in a time division manner.

The water conductivity parameter on-line measuring method provided in this embodiment, wherein,

the sending of sine wave excitation signals with different frequencies to the electrode a310 includes:

the receiving of the coupled signals with different frequencies from the electrode B311 includes:

the processor 320 receives the sine wave coupling signal having the first, second and third frequencies, which is the serial voltage division of the equivalent resistance of water and the sampling resistance, through the receiving channel module 390 and the receiving electrode B311.

Specifically, the electrode B311 detects a coupling signal of the liquid 300 to the sine wave excitation signal having the first, second, and third frequencies injected by the electrode a310, the coupling signal being a partial pressure signal of the liquid 300 to the sine wave excitation signal having the first, second, and third frequencies;

the coupled signal detected by the electrode B311 is sampled by the coupled signal sampling module 340, and then sent to the processor 320 through the coupled signal amplifying module 341, the coupled signal peak holding module 342, and the a/D sampling module 343.

Further, after the coupling signal detected by the electrode B311 is sampled by the coupling signal sampling module 340, the coupling signal is sent to the processor 320 through the coupling signal amplifying module 341, the coupling signal peak holding module 342, and the a/D sampling module 343, which includes:

the coupled signal amplifying module 341, the coupled signal peak holding module 342, and the a/D sampling module 343 process the sine wave coupled signals having the first, second, and third frequencies in a time division manner; or,

the coupled signal amplifying module 341, the coupled signal peak-hold module 342, and the a/D sampling module 343 process the sine wave coupled signals having the first, second, and third frequencies in a parallel manner;

preferably, the coupled signal amplifying module 341, the coupled signal peak-hold module 342, and the a/D sampling module 343 process the sine wave coupled signals having the first, second, and third frequencies in a time-division manner.

Specifically, the coupling signal amplifying module 341 amplifies the collected weak sine wave coupling signals of the first, second, and third frequencies.

In particular, the coupled signal peak hold module 342 holds the peak values of the sine wave coupled signals of the first, second, and third frequencies.

Specifically, the a/D sampling module 343 performs analog-to-digital conversion on the peak values of the sine wave coupled signals at the first, second, and third frequencies, and the converted digital signals are sent to the processor 320.

the calculating the voltage values corresponding to the coupling signals with different frequencies specifically includes:

calculating first, second and third voltage values corresponding to peak values of the sine wave coupling signals of the first, second and third frequencies;

the calculating the conductivity by using the voltage values corresponding to the coupling signals with different frequencies specifically includes:

the equivalent resistance Rx is calculated using the first, second and third voltage values and then converted into the conductivity of the liquid 300.

The indirect conductivity measurement model includes the common effects of the electrodes, the insulating isolation layer and the water body, and the indirect conductivity measurement model adopted in the present embodiment is shown in fig. 2, wherein,

cy is the equivalent capacitance generated between the conductive layers of the two electrodes, Cx is the equivalent capacitance formed between the conductive layers of the two electrodes and the measured liquid, and Rx is the equivalent resistance of the measured liquid. The equivalent impedance model between the two electrodes is shown as formula (1).

… … … … … …. formula (1)

Transforming the formula (1) to obtain a complex expression (2)

… … … …, formula (2)

Obtaining the corresponding output impedance of the electrode output in the liquid by the modular operation of the formula (2)At this time, to solve Rx, Cy, Cx only needs to select three suitable sine wave excitation signals, that is, the sine wave excitation signals of the first, second, and third frequencies, and obtain the first, second, and third voltage values corresponding to the peak values of the sine wave coupling signals of the first, second, and third frequencies, so as to solve the corresponding parameters.

the calculating the equivalent resistance Rx using the first, second, and third voltage values, and then converting into the conductivity of the liquid 300 specifically includes:

obtaining temperature values of the liquid 300 using the temperature measurement module 360

The normalized equivalent conductivity of the liquid 300 is solved using the temperature value of the liquid 300.

The normalized equivalent conductivity uses a calculation relationship of:

conductivity values at 25 degrees = actual conductivity values/(1 +0.02 x (t-25));

wherein, 0.02 is a temperature compensation coefficient; and t is the actual water temperature.

Example II A sampling device

Referring to fig. 2 and 3, an embodiment of a sampling device provided by the present invention includes:

The present embodiment provides an apparatus, wherein,

the water quality online detection operation performed by the water quality detection module 230 specifically includes:

acquiring initial measurement parameters of water quality;

The present embodiment provides an apparatus, wherein,

the operation of acquiring the initial water quality measurement parameter executed by the water quality detection module 230 specifically includes:

initial measurement parameters for calculating conductivity are obtained.

The present embodiment provides an apparatus, wherein,

the operation of receiving the water sampling instruction from the network side, which is executed by the communication module 220, specifically includes:

indicating information for water body sampling operation;

specific time information for water body sampling operation is carried out;

carrying out water body sampling operation mode information; and

The present embodiment provides an apparatus, wherein,

the operation that the sampling control module 210 executed controls the sampling module according to the water quality online detection result or the water sampling instruction specifically includes:

E=E0+(2.303RT/nF)×log(A)

2.303 is a factor by which natural numbers are converted to base 10 logarithms;

r is a gas parameter (8.314J/D/M);

t is the absolute temperature;

n is the ionic charge (including label) F is the Faraday constant (96500C/mol);

log (a) is the logarithm of the measured ion activity;

The present embodiment provides an apparatus, wherein,

the operation executed by the communication module 220 to send the sampling completion or sampling failure indication information to the network side specifically includes:

Specifically, the water quality measuring module 230 according to the present embodiment, as shown in fig. 2 and 3, includes:

excitation channel module 380, electrode a310, receive channel module 390, electrode B311, and processor 320; wherein,

the excitation channel module 380 is used for sending sine wave excitation signals with different frequencies to the electrode a310, and comprises an excitation signal generation module 330 and an excitation signal amplification module 331;

an electrode a310 for injecting sine wave excitation signals of different frequencies into the liquid 300, comprising a metal conductor;

a receiving channel module 390 for receiving the coupled signals with different frequencies from the electrode B311, comprising a coupled signal sampling module 340, a coupled signal amplifying module 341, a coupled signal peak holding module 342, and an A/D sampling module 343;

the electrode B311 is used for detecting coupling signals of the liquid 300 to sine wave excitation signals with different frequencies and comprises a metal conductor;

the processor 320 is configured to calculate voltage values corresponding to the coupling signals with different frequencies, and calculate the conductivity using the voltage values, and includes an arithmetic unit, a memory unit, and a peripheral interface circuit.

The water quality measuring module 230 of the present embodiment is provided, wherein,

the excitation channel module 380 is configured to perform an operation of sending sine wave excitation signals with different frequencies to the electrode a310, and specifically includes the following operation steps:

the receiving channel module 390 is configured to perform an operation of receiving the coupled signals with different frequencies from the electrode B311, and specifically includes the following operation steps:

the processor 320 is configured to perform operations of calculating voltage values corresponding to the coupling signals with different frequencies and calculating electrical conductivity by using the voltage values corresponding to the coupling signals with different frequencies, and specifically includes:

… … … … … …. formula (1)

Transforming the formula (1) to obtain a complex expression (2)

… … … …, formula (2)

a processor 320, configured to perform an operation of calculating an equivalent resistance Rx using the first, second, and third voltage values, and then converting the calculated equivalent resistance Rx into the conductivity of the liquid 300, specifically including:

acquiring a temperature value of the liquid 300 by using a temperature measuring module 360;

The normalized equivalent conductivity uses a calculation relationship of:

The water quality measuring module 230 of the present embodiment further includes a temperature measuring module 360, and specifically,

the temperature sensor included in the temperature measurement module 360 is not directly placed in the measured liquid, and the temperature sensor included in the temperature measurement module 360 utilizes a good heat conductor as a heat conduction channel and as a watertight component to reduce the complexity of the watertight structure.

Specifically, the temperature sensor included in the temperature measurement module 360 uses a good thermal conductor as a heat conduction channel and as a watertight component, and a specific implementation manner is that the temperature sensor included in the temperature measurement module 360 is placed at the rear side of the electrode a310 or the electrode B311, and two effects of watertight and heat conduction are achieved by using the electrode a310 or the electrode B311.

The water quality measuring module 230 of the present embodiment has a direct communication channel with the communication module 220, and specifically,

the communication module 220 is electrically connected to the processor 320 and electrically connected or wirelessly connected to a communication node on the network side.

Specifically, the communication module 220 acquires a control command from the communication node of the network side or transmits a measurement result to the communication node of the network side through its electrical or radio connection with the processor 320 and the communication node of the network side.

The processor 320 is electrically connected to both the sampling control module 210 and the communication module 220, and the processor 320 may send the water quality measurement data to the sampling control module 210, or may send the water quality measurement data to the communication module 220, and send the water quality measurement data to the network side through the communication module 220.

Preferably, a radio connection exists between the communication module 220 and a communication node on the network side, and the radio connection is a radio connection conforming to an LoRa communication protocol or an NB-IOT communication protocol.

The method and the device provided by the embodiment of the invention can be wholly or partially realized by using an electronic technology, a radio transmission technology and an internet technology; the method provided by the embodiment of the invention can be wholly or partially realized by software instructions and/or hardware circuits; the modules or units included in the device provided by the embodiment of the invention can be realized by adopting structural components and electronic components.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

The method and the device provided by the invention overcome at least one of the defects that the existing conductivity measurement technology cannot automatically sample and store the overproof sewage and cannot recheck the online monitoring result. The online monitoring result can be retested, the retesting time is flexible, the monitoring site does not need to be accessed immediately, the monitoring workload is reduced, and the method has practicability.

Claims

1. A sampling method comprising the steps of:

2. The method of claim 1, wherein,

the online detection of water quality comprises the following steps:

acquiring initial measurement parameters of water quality;

3. The method of claim 2, wherein,

4. The method of claim 1, wherein,

5. The method of claim 1, wherein,

6. The method of claim 1, wherein,

7. A sampling device, comprising:

8. The apparatus of claim 7, wherein,

acquiring initial measurement parameters of water quality;

9. The apparatus of claim 8, wherein,

initial measurement parameters for calculating conductivity are obtained.

10. The apparatus of claim 7, wherein,

11. The apparatus of claim 7, wherein,

12. The apparatus of claim 7, wherein,