CN104567831A - Easily precipitated water quality open channel flow measuring instrument and measurement method thereof - Google Patents

Abstract

The invention belongs to the technical field of silt flow measurement, and in particular relates to a flow measuring instrument and a measuring method for an open channel of easy-to-sediment water quality. It can measure open channel flow in real time, online and accurately without being affected by the thickness of silt deposits, and solves the problem of inaccurate open channel flow measurement. In order to achieve the above object, the technical solution adopted in the invention includes a photoelectric silt thickness measurement part, a liquid impulse flow velocity measurement part, a hand-held terminal and a data processing main board, and the photoelectric silt thickness measurement part is connected to the signal output port of the main board shell through the communication line of the launch board On the top, the liquid impulse flow rate measurement component is connected to the force measurement signal port of the main board shell through the force measurement signal line, the handheld terminal is connected to the RS485 communication port of the main board shell through the RS485 data communication line, and the data processing main board is connected with the signal output port and the signal receiving port respectively Port, force measurement signal port and RS485 communication port connection.

Description

A flow measuring instrument and measuring method for an open channel of easy-to-sediment water quality

1. Technical field

The invention belongs to the technical field of silt flow measurement, and in particular relates to a flow measuring instrument and a measuring method for an open channel of easy-to-sediment water quality.

2. Background technology

All the water flow movement with free surface in rivers, canals and artificial tunnels is called open channel flow. The open channel flow meter is used in urban water supply diversion canals, thermal power plant cooling water diversion and drainage channels, sewage treatment inflow and discharge channels, industrial and mining wastewater discharge, and channels for water conservancy projects and agricultural irrigation. At present, the application of flow calculation and measurement methods in China is still in its infancy on the whole, and some achievements have been made, but there is still a big gap compared with foreign countries.

Commonly used open channel flow meters can be roughly divided into weir method, flow channel method, flow velocity-water level calculation method and electromagnetic flowmeter method according to the measurement principle. As a common drainage facility for coal mines, the open channel is inevitably mixed with coal cinders, soil and other particles and a small amount of garbage due to its specific use environment. When these cinders and soil are slowly deposited in the open channel, the water level will slowly rise. The open channel flow measuring instrument installed before needs to use the distance from the weir plate to the water level when measuring the flow. Due to the precipitation of impurities, the sensor can measure The distance from the weir plate to the horizontal plane is inaccurate, and the flow rate calculated from this is naturally inaccurate. Similarly, in the measurement of the trough flowmeter, if impurities are deposited on the upstream side of the throat, the measured flow rate relative to the bottom of the throat will be inaccurate. The water level h on the upstream side will be higher, so the measured flow rate is obviously inaccurate. Therefore, no matter which of the above measurement methods has the same problem: the thickness of silt sedimentation has an impact on the accuracy of flow measurement.

Flow meters can be divided into rotor flow meters and non-rotor flow meters in terms of their working methods. Rotor-type flow meters are simple and practical, but have no automation system interface; non-rotor-type flow meters mainly include time-difference ultrasonic flow meters, radio wave flow meters and ultrasonic Doppler flow meters, etc. The interface is connected, but the installation is difficult, and the sediment has an impact on the test distance; the traveling Doppler profile velocity measurement system is not suitable for long-term monitoring, and there is also the problem that the sediment affects the test distance; the horizontal Doppler profile velocity measurement system It can be connected to the monitoring system for long-term monitoring, but there is still the problem that sediment affects the test distance.

In order to solve the above problems, it is very necessary to develop an open channel flow measuring instrument that solves the influence of the thickness of silt on the measurement accuracy.

3. Contents of the invention

In order to solve the deficiencies in the above-mentioned background technology, the present invention provides a sedimentation-prone water quality open channel flow measuring instrument and a measuring method thereof. It can measure open channel flow in real time, online and accurately without being affected by the thickness of silt deposits, and solves the problem of inaccurate open channel flow measurement.

In order to achieve the above object, the technical solution adopted by the present invention is: a kind of sedimentation-prone water quality open channel flow meter, which is characterized in that: it includes a photoelectric silt thickness measurement part, a liquid impulsive flow velocity measurement part, a hand-held terminal and a data processing main board. The photoelectric silt thickness measuring part and the liquid impulse flow rate measuring part are connected as a whole through a screw; the photoelectric silt thickness measuring part is connected to the signal output port of the main board shell through the communication line of the transmitting board, and connected through the communication line of the receiving board. On the signal receiving port of the main board shell, the liquid impulse flow velocity measuring part is connected to the force measuring signal port of the main board shell through the force measuring signal line, and the described handheld terminal is connected to the RS485 communication port of the main board shell through the RS485 data communication line Above, the data processing main board is respectively connected with the signal output port, the signal receiving port, the force measurement signal port and the RS485 communication port.

The photoelectric silt thickness measuring part includes a shell bottom plate and a shell top plate 1 parallel to each other, and a transmitting plate shell and a receiving plate shell perpendicular to the shell are arranged between the shell bottom plate and the shell top plate 1, and the transmitting plate shell A transmitting board is embedded on the top, and a receiving board is embedded on the receiving board shell;

There are several light-emitting diodes equidistantly distributed on the emitting board, and the emitting board is sealed on the emitting board shell by waterproof glue;

There are several phototransistors equidistantly distributed on the receiving board, and the receiving board is sealed on the housing of the receiving board by waterproof glue;

The light-emitting diodes are in one-to-one correspondence with the lamp holders of the phototransistors;

The transmitting board shell and the receiving board shell are respectively provided with a transmitting board communication port and a receiving board communication port.

The liquid impulsive force flow rate measuring component includes a second casing top plate, on which a load cell is connected through sensor fixing bolts, and one end of the second casing top plate is connected with a force rod through a rotating shaft.

A mainboard shell is also fixed on the second shell top plate by bolts, and a data processing mainboard is fixed inside the mainboard shell.

The load cell is connected to the force-measurement signal port through the force-measurement signal line.

The handheld terminal is connected with the data processing main board through the RS485 data communication line for parameter setting.

The photoelectric silt thickness measurement part is combined with the data processing main board to measure the water level and mud level position; the liquid impulse flow velocity measurement part is combined with the data processing main board to measure the flow rate of the water flow; the handheld terminal is used for Setting parameters.

The measuring method of described a kind of easy sedimentation water quality open channel flowmeter, is characterized in that described method step is:

(1) Choose the location to install the instrument: choose a place where the channel is regular, the bottom of the channel is flat, and the water velocity before and after the installation location is relatively stable;

(2) Record the installation parameters: adjust the bottom of the stress rod to be 3~5cm away from the bottom plate of the shell, and record the distance as the height of the stress rod; measure the width of the canal, the distance l ₁ from the rotating shaft to the stress point of the load cell, and the distance from the rotating shaft to the stress point The distance between the bottom of the force bar is l ₂ , and the width of the force bar is l _width ;

(3) Install the instrument into the open channel: put the measuring device as a whole into the selected installation position, the bottom plate of the shell is in close contact with the bottom of the channel, and the water flows on the bottom plate of the shell, and along the direction of the water flow, first passes through the liquid impulse flow velocity measuring part, and then passes through Photoelectric silt thickness measurement components;

(4) Determine the calibration flow rate: use the standard table method to measure the water velocity at the same cross-section of the bottom, middle, surface and force bar respectively, and obtain a relatively stable average value as the calibration flow rate;

(5) Use the handheld terminal to set parameters: set the recorded parameters and calibrated flow rate into the data processing main board, and return to the current monitoring interface of the handheld terminal to observe the displayed data, including water level, mud level, temperature, flow, flow rate, momentum;

(6) Data operation.

According to the collected parameters and the parameters set by the user, the data processing board performs calculation and processing to obtain the final water level, mud level, temperature, flow rate, flow velocity and momentum.

First of all, the data processing main board first calculates the water level, mud level and temperature. According to the signal collected by the temperature acquisition circuit, the data processing main board can directly calculate the temperature. According to the sampling value of the photoelectric silt thickness measuring part and the base value set by the user, the water level and mud level can be obtained;

Secondly, according to the height of the stress rod set by the user, the actual depth h of the stress rod into the water (water level - height of the stress rod) is obtained;

Third, calculate the initial force F ₀ . The data processing main board calculates the initial force F ₀ according to the pressure F _pressure on the load cell collected by the liquid impulse flow rate measurement part, as well as l ₁ , l ₂ , l _width , h, and calibration flow rate. The comprehensive calculation formula is:

Fourth, calculate the flow velocity v. The data processing main board calculates the actual water flow velocity according to the above formula according to the pressure F _pressure on the load cell, and l ₁ , l ₂ , l _width , h, and initial force F ₀ ;

Finally, calculate the traffic. Subtract the height of the mud level from the height of the water level to obtain the actual height of the cross-section without silt. According to the shape of the cross-section (trapezoidal, rectangular), calculate the accurate area of the cross-section. Combined with the calculated flow velocity, use the flow velocity-area The flow rate of the water flow can be obtained by the method: Q=vSt, where Q is the flow rate of the water flow, S is the cross-sectional area of the water, and t is the time.

(7) Access to the hydrological monitoring system: use the RS485 communication line to connect the RS485 communication port of the measuring instrument to the RS485 communication interface of the hydrological monitoring system to build a communication line between the two, and the measuring instrument will upload the collected data to the hydrological monitoring System software, the user can see the water level, mud level, temperature, flow, flow velocity, momentum information on the real-time data interface of the hydrological monitoring system software.

Compared with the prior art, the present invention has the following advantages and effects: ①Multi-parameter monitoring: It can monitor various hydrological parameters such as water velocity, silt thickness, water level, water temperature, and flow;

②Online real-time monitoring: This measuring instrument has a system interface, which can be directly connected to the hydrological monitoring system, and the monitored hydrological parameters can be analyzed and processed through the hydrological monitoring system, which is suitable for long-term monitoring;

③Solve the influence of silt sedimentation thickness on measurement accuracy: When the measuring instrument calculates the flow rate using the flow velocity-area method, the influence of silt sedimentation thickness on the flow area is considered, and the silt thickness is subtracted from the calculation to obtain the area is the direct cross-sectional area of the water flow, so the real open channel flow value can be calculated more accurately;

④Simple and convenient operation: This measuring instrument can be connected to the hydrological monitoring system for joint use, or it can be used alone as a portable device. It is easy to operate and easy to use.

The invention mainly solves the technical problem that the sedimentation thickness of the open channel affects the flow measurement accuracy, and can be connected to a hydrological monitoring system to monitor the open channel flow and related hydrological parameters in real time on-line, which can create huge economic and social benefits.

4. Description of drawings

Fig. 1 is a structural representation of the present invention;

Fig. 2 is a structural diagram of the photoelectric silt thickness measuring part in Fig. 1;

Fig. 3 is a structural diagram of the liquid impulsive flow velocity measuring component in Fig. 1;

Fig. 4 is an enlarged view of the force measuring member in Fig. 3;

Fig. 5 is a structural diagram of a data processing mainboard;

Fig. 6 is the logical block diagram of data processing mainboard;

Fig. 7 is a schematic diagram of a power processing circuit;

Fig. 8 is a schematic diagram of processor and temperature acquisition and reset circuit;

Fig. 9 is a schematic diagram of an addressing circuit;

Fig. 10 is a schematic diagram of the pressure acquisition circuit;

Fig. 11 is a schematic diagram of a memory circuit;

Figure 12 is a schematic diagram of the RS485 communication circuit;

Figure 13 is a schematic diagram of the basic principle of the launch board;

Fig. 14 is a schematic diagram of the basic principle of the receiving board;

Fig. 15 is a block diagram of the terminal motherboard;

Fig. 16 is a circuit schematic diagram of the terminal motherboard except the power processing part;

Fig. 17 is a schematic diagram of the film button circuit;

In the figure, 1-transmitting board shell, 2-receiving board shell, 3-transmitting board, 4-receiving board, 5-light-emitting diode, 6-photosensitive transistor, 7-waterproof glue, 8-housing fixing bolt, 9-housing bottom plate , 10-connection board, 11-shell top board one, 12-communication port of launch board, 13-communication port of receiving board, 14-data processing main board, 15-signal output port, 16-signal receiving port, 17-RS485 communication port, 18—shell top plate 2, 19—load sensor, 20—sensor fixing bolt, 21—force point, 22—force rod, 23—rotating shaft, 24—force measuring signal port, 25—main board shell, 26—handheld terminal , 27—transmission board communication line, 28—receiving board communication line, 29—force measuring signal line, 30—RS485 data communication line, 31—screw rod.

5. Specific implementation

The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

See Fig. 1-Fig. 5: a kind of easy-to-sediment water quality open channel flow measuring instrument, comprises photoelectric type silt thickness measurement part, liquid impulsive flow velocity measurement part, hand-held terminal 26 and data processing main board 14, described photoelectric type silt thickness measurement part and The liquid impulsive flow rate measuring part is connected as a whole by the screw rod 31; the photoelectric mud thickness measuring part is connected to the signal output port 15 of the main board shell 25 of the data processing main board 14 through the transmitting board communication line 27, and through the receiving board communication line 28 is connected to the signal receiving port 16 of the main board shell 25 of the data processing main board 14, and the described liquid impulse flow velocity measuring part is connected to the force measuring signal port 24 of the main board shell 25 of the data processing main board 14 through the force measuring signal line 29, so The above-mentioned handheld terminal 26 is connected to the RS485 communication port 17 of the mainboard shell 25 of the data processing mainboard 14 through the RS485 data communication line 30. The data processing main board 14 is respectively connected with the signal output port 15 , the signal receiving port 16 , the force measurement signal port 24 and the RS485 communication port 17 .

The photoelectric silt thickness measuring part comprises a shell bottom plate 9 and a shell top plate one 11 parallel to each other, and a transmitting plate shell 1 and a receiving plate shell 2 perpendicular thereto are arranged between the shell bottom plate 9 and the shell top plate one 11, A transmitting board 3 is embedded on the transmitting board shell 1, and a receiving board 4 is embedded on the receiving board shell 2;

Several light emitting diodes 5 are equidistantly distributed on the emitting board 3, and the emitting diodes 5 are embedded in the emitting board 3, and the emitting board 3 is sealed on the emitting board shell 1 by waterproof glue 7, so that The lamp caps of the above-mentioned light-emitting diodes 5 are not all sealed;

Several phototransistors 6 are equidistantly distributed on the receiving board 4, the phototransistors 6 are embedded in the receiving board 4, and the receiving board 4 is sealed on the receiving board shell 2 by waterproof glue 7, so The lamp caps of the phototransistor 6 described above are not all sealed;

The light-emitting diodes 5 correspond to the caps of the phototransistors 6 one by one; the distance between two adjacent light-emitting diodes 5 is equal to the distance between two adjacent phototransistors 6 .

The transmitting board shell 1 and the receiving board shell 2 are respectively provided with a transmitting board communication port 12 and a receiving board communication port 13 .

One end of the transmitting board communication port 12 is connected to the transmitting board 3, and the other end is connected to the signal output port 15 of the main board shell 25 of the data processing main board 14, and one end of the receiving board communication port 13 is connected to the receiving board 4 , and the other end is connected to the signal receiving port 16 of the motherboard shell 25 of the data processing motherboard 14.

The data processing mainboard 14 is arranged in the mainboard casing 25 .

The liquid impulsive force flow rate measuring part includes the shell top plate 2 18, and the shell top plate 2 18 is composed of carbon steel or stainless steel plate welded with two fixing seats respectively fixing the rotating shaft 23 and the load cell 19, and the shell top plate 2 On 18, the load cell 19 is connected to the fixed seat through the sensor fixing bolt 20. The model of the load cell is L6D-Cx-xxkg-0.4B, and the measuring range can meet 2.5kg～50kg. One end is connected with a force rod 22 through a rotating shaft 23, and a mainboard shell 25 is fixed on the top plate 18 of the shell by bolts, and a data processing mainboard 14 is fixed inside the mainboard shell 25, and the load cell 19 is passed through the measuring The force signal line 29 is connected to the force measurement signal port 24 .

The handheld terminal includes a terminal shell, a liquid crystal display, a membrane button, a terminal main board, and an RS485 communication port. The front of the terminal shell is provided with membrane buttons and a liquid crystal display, an RS485 communication port is left on the upper end, and a terminal main board is fixed inside the terminal shell. The terminal main board is connected with the membrane button, the liquid crystal display screen and the RS485 communication port, and is used to complete parameter setting and display functions.

The two ends of the transmitting board shell 1 and the receiving plate shell 2 are vertically fixed on the shell bottom plate 9 and the shell top plate 11 by shell fixing bolts 8, and the described transmitting plate shell 1 and the receiving plate shell 2 are arranged parallel to each other, and the middle Fastened by connecting plate 10.

The photoelectric silt thickness measurement unit is combined with the data processing main board to calculate the silt thickness, water level and temperature according to the different sampling values in different media.

The liquid impulsive force flow rate measurement component is combined with the data processing main board, and the water flow impulsive force is converted according to the pressure acting on the load cell, and then the flow rate is calculated by combining the water level height and the thickness of the silt.

The data processing main board first uses the water level to subtract the mud level to obtain the actual height of the water passing section, and then according to the shape of the water passing section (trapezoidal, rectangular), accurately calculates the area of the water passing section without the thickness of the silt, and uses it in combination with the flow rate Velocity-area method to obtain accurate open channel flow.

The steps of a method for measuring an easy-to-sedimentation water quality open channel flow meter are:

(1) Choose the location to install the instrument: try to choose a place where the channel is relatively regular, the bottom of the channel is relatively flat, and the water velocity before and after the installation position is relatively stable;

(2) Record the installation parameters: adjust the bottom of the stress rod to be 3~5cm away from the bottom plate of the shell, and record the distance as the height of the stress rod; measure the width of the canal, the distance l ₁ from the rotating shaft to the stress point of the load cell, and the distance from the rotating shaft to the stress point The distance between the bottom of the force bar is l ₂ , and the width of the force bar is l _width ;

(3) Install the instrument into the open channel: Put the measuring device as a whole into the selected installation position, the bottom plate of the shell is in close contact with the bottom of the channel, and the water flows over the bottom plate of the shell. Along the direction of water flow, it first passes through the liquid impulsive flow velocity measuring part, and then passes through the photoelectric silt thickness measuring part;

(4) Determine the calibration flow rate: Use the standard table method to measure the water velocity at the same cross-section of the bottom, middle, surface, etc. and the stress rod, and calculate a relatively stable average flow rate as the calibration flow rate for flow rate calibration ;

(5) Use the handheld terminal to set parameters: set the recorded parameters and calibrated flow rate into the data processing main board, and return to the current monitoring interface of the handheld terminal to observe the displayed data, including water level, mud level, temperature, flow, flow rate, momentum.

(6) Data operation.

According to the collected parameters and the parameters set by the user, the data processing board performs calculation and processing to obtain the final water level, mud level, temperature, flow rate, flow velocity and momentum.

First of all, the data processing main board first calculates the water level, mud level and temperature. According to the signal collected by the temperature acquisition circuit, the data processing main board can directly calculate the temperature. According to the sampling value of the photoelectric silt thickness measuring part and the base value set by the user, the water level and mud level can be obtained;

Secondly, according to the height of the stress rod set by the user, the actual depth h of the stress rod into the water (water level - height of the stress rod) is obtained;

Third, calculate the initial force F ₀ . The data processing main board calculates the initial force F ₀ according to the pressure F _pressure on the load cell collected by the liquid impulse flow rate measurement part, as well as l ₁ , l ₂ , l _width , h, and calibration flow rate. The comprehensive calculation formula is:

Fourth, calculate the flow velocity v. The data processing main board calculates the actual water flow velocity according to the above formula according to the pressure F _pressure on the load cell, and l ₁ , l ₂ , l _width , h, and initial force F ₀ .

Finally, calculate the traffic. Subtract the height of the mud level from the height of the water level to obtain the actual height of the cross-section without silt. According to the shape of the cross-section (trapezoidal, rectangular), calculate the accurate area of the cross-section. Combined with the calculated flow velocity, use the flow velocity-area The flow rate of the water flow can be obtained by the method: Q=vSt, where Q is the flow rate of the water flow, S is the cross-sectional area of the water, and t is the time.

(7) Access to the hydrological monitoring system: use the RS485 communication line to connect the RS485 communication port of the measuring instrument to the RS485 communication interface of the hydrological monitoring system to build a communication line between the two. The measuring instrument uploads the collected data to the hydrological monitoring system software, and the user can see the information of water level, mud level, temperature, flow rate, flow velocity and momentum on the real-time data interface of the hydrological monitoring system software.

Referring to Fig. 6: described data processing mainboard 14 comprises processor circuit, power processing circuit, reset circuit, memory circuit, RS485 communication circuit, address selection circuit, pressure acquisition circuit and temperature acquisition circuit, described processor circuit is respectively connected with Including processor circuit, power processing circuit, reset circuit, memory circuit, RS485 communication circuit, address selection circuit, pressure acquisition circuit and temperature acquisition circuit, the power processing circuit is connected with reset circuit, memory circuit, RS485 communication circuit, address selection circuit respectively , The pressure acquisition circuit is connected with the temperature acquisition circuit.

Referring to Fig. 7: the power processing circuit mainly provides power supply function for each chip on the data processing motherboard 14, DC_IN in the figure is an external 18V DC power supply, VCC represents the output voltage is 3.3V, GND represents the power ground, Supply power to each chip.

Referring to Fig. 8: the main chip of the processor circuit is a single-chip microcomputer MSP430F5438A, which is used to complete the control of each part of the circuit, the collection and calculation of parameters. A 32768HZ crystal oscillator is connected between pins 13 and 14, and a 16MHZ crystal oscillator is connected between pins 89 and 90. The two crystal oscillators provide the required clock signals for each chip. 2, 3 pins are connected to the signal output port 15 of the data processing main board 14, and are used to connect with the launch board 3 to control the light emitting of the light-emitting diode 5, and the 17-24 pins are connected to the signal receiving port 16 of the data processing main board 14, with It is connected with the receiving board 4 and is a part of the address selection circuit.

The main chip of the temperature acquisition circuit is DS18B20, and its pin 2 is connected with the 26 pin of MSP430F5438A to complete the temperature acquisition function.

The main chip of the reset circuit is SP706SEN, and its pins 6 and 7 are respectively connected with pins 79 and 96 of MSP430F5438A.

Referring to Fig. 9: the main chip of the address selection circuit is a CD4051BCM chip, and its pins 9, 10, 11 are respectively connected to the pins 25, 24, 23 of the MSP430F5438A; its pins 13, 14, 15, 12 , 1, 5, 2, 4 are respectively connected to the signal receiving port 16 of the data processing mainboard, for connecting with the receiving board. The endpoint labeled TA in the circuit diagram is connected to pin 97 of MSP430F5438A, and is used to input the signal received by the phototransistor on the receiving board into MSP430F5438A for calculation.

See Fig. 10: the main chip of the pressure acquisition circuit is ADS1246 chip, which is used to acquire the pressure on the load cell. The pins 3, 4, 11, 12, 13, 14, 15, and 16 of the chip ADS1246 are respectively connected to the pins 43, 47, 48, 49, 31, 32, 50, and 51 of the chip MSP430F5438A, and the pressure is collected by the MSP430F5438A Control and operate.

Referring to FIG. 11 : the main chip of the memory circuit is 24LC1025, and its pins 5, 6, and 7 are connected to pins 69, 70, and 68, respectively.

See Figure 12: the main chip of the RS485 communication circuit is ADM2483, and its pins 3, 4, and 6 are respectively connected to pins 81, 82, and 80 of MSP430F5438A for sending and receiving RS485 signals; ports 485B, 485A are used for communicating with other external devices or software.

Refer to Figure 13: The 3-part circuit board of the launch board is mainly composed of N light-emitting diodes and a shift chip SN74HC164, and the light-emitting diodes are lit according to the control of the data processing main board.

The emission board 3 is mainly realized by the shift chip SN74HC164 to sequentially light up a plurality of lamps. SN74HC164 is an 8-bit serial-to-parallel conversion control chip, which is mainly used in digital circuits and LED display control circuit applications. This product uses it as an 8-channel output LED driver dedicated chip. Give the chip a high-level signal to shift the output pins sequentially, and the LED lights are lit sequentially. At the same time, the output signal of the last pin controlled by the chip is used as the input signal of the next chip, and then iteratively proceeds. Sequential lighting of multiple lamps can be realized.

See Figure 14: The 4-part circuit board of the receiving board is mainly composed of N photosensitive transistors and a multiplexer MM74HC4051. When the emitting board emits light, the corresponding light tube of the receiving board will receive a certain intensity of light signal to conduct. According to the strength of the light signal, the conduction strength is different, and the data processing main board calculates according to the received intensity of each lamp tube, so as to judge the water level and mud level. The receiving board mainly uses the device photosensitive transistor PT333, which is turned on when it receives the light of the transmitting tube, and the size of the turn-on is different according to the received light intensity; A lamp that needs to output the collected signal.

Referring to Figure 15: the mainboard of the handheld terminal includes a power processing circuit, a processor circuit, a reset circuit, an RS485 communication circuit, a liquid crystal display interface circuit, and a keyboard interface circuit, and the processor circuit is connected to the power processing circuit, the reset circuit, The RS485 communication circuit, the liquid crystal display interface circuit and the keyboard interface circuit are connected, and the power processing circuit is respectively connected with the reset circuit, the RS485 communication circuit, the liquid crystal display interface circuit and the keyboard interface circuit;

Referring to Fig. 7: the power processing circuit mainly provides the power supply function for each chip, liquid crystal display screen, and membrane button on the terminal main board.

Referring to Fig. 16: the main chip of the processor circuit is a single-chip microcomputer MSP430F5438A, which is used to complete the control of each part of the circuit. A 32768HZ crystal oscillator is connected between pins 13 and 14, and a 16MHZ crystal oscillator is connected between pins 89 and 90. The two crystal oscillators provide the required clock signals for each chip. The main chip of the reset circuit is SP706SEN, and its pins 6 and 7 are respectively connected with pins 79 and 96 of MSP430F5438A. The main chip of the described RS485 communication circuit is ADM2483, and its pins 3, 4, 6 are connected with the pins 40, 33, 39 of MSP430F5438A respectively, and are used for sending and receiving RS485 signals; ports 485B, 485A are used for communicating with other external Device communication. The external interface of the liquid crystal display interface circuit is YJ1, which is mainly connected with the liquid crystal display of the model KYDZ12864C-3.3V, and each pin of the interface YJ1 is connected with the corresponding pin of the MSP430F5438A on the terminal mainboard, and the corresponding relationship of the pins has been given in the figure. The external interface of the keyboard interface circuit is CZ1, its pins 1-8 are respectively connected with pins 17-24 of MSP430F5438A, and pin 12 is connected with pin 1 of SP706SEN for completing the reset function.

See Figure 17: the membrane key is composed of 16 keys including number keys 0~9, ".", "←", "→", "Confirm", "ON/OFF" and "Reset". The circuit schematic is given in Figure 17.

Claims (8)

1. An easy-to-precipitate water quality open channel flow measuring instrument is characterized in that: comprise photoelectric type silt thickness measurement part, liquid momentum flow velocity measurement part, hand-held terminal (26) and data processing main board (14), described photoelectric type silt thickness The measuring part and the liquid impulse flow rate measuring part are connected as a whole through a screw (31); the photoelectric mud thickness measuring part is connected to the signal output port (15) of the main board shell (25) through the launch board communication line (27) , connected to the signal receiving port (16) of the main board casing (25) through the receiving board communication line (28), and the described liquid impulse flow velocity measurement component is connected to the measurement part of the main board casing (25) through the force measurement signal line (29). Force signal port (24), described hand-held terminal (26) is connected on the RS485 communication port (17) of main board shell (25) by RS485 data communication line (30), described data processing main board (14) and The signal output port (15), the signal receiving port (16), the force measurement signal port (24) and the RS485 communication port (17) are connected. 2. A kind of easy-to-sediment water quality open channel flowmeter according to claim 1, is characterized in that: described photoelectric type silt thickness measuring part comprises shell bottom plate (9) and shell top plate one (11) parallel to each other, so Between the shell bottom plate (9) and the shell top plate one (11) are provided with a launch plate shell (1) and a receiver plate shell (2) perpendicular thereto, and the launch plate shell (1) is embedded with a launch plate (3), the receiving board shell (2) is embedded with a receiving board (4); Several light-emitting diodes (5) are equidistantly distributed on the emitting board (3), and the emitting board (3) is sealed on the emitting board casing (1) by waterproof glue (7); Several phototransistors (6) are equidistantly distributed on the receiving board (4), and the receiving board (4) is sealed on the receiving board shell (2) by waterproof glue (7); Described light-emitting diode (5) corresponds to the lamp holder of phototransistor (6) one by one; The transmitting board shell (1) and the receiving board shell (2) are respectively provided with a transmitting board communication port (12) and a receiving board communication port (13). 3. A kind of sedimentation-prone water quality open channel flow measuring instrument according to claim 1, characterized in that: said liquid impulsive force flow velocity measuring part comprises a shell top plate two (18), and said shell top plate two (18) passes through The sensor fixing bolt (20) is connected with a load cell (19), and one end of the top plate 2 of the casing is connected with a force rod (22) through a rotating shaft (23). 4. a kind of easy sedimentation water quality open channel flow measuring instrument according to claim 2, is characterized in that: also be fixed with mainboard shell (25) by bolt on described shell top plate two (18), described mainboard shell ( 25) a data processing main board (14) is fixed inside. 5. A kind of sedimentation-prone water quality open channel flow measuring instrument according to claim 2, characterized in that: said load cell (19) is connected to the force-measuring signal port (24) through a force-measuring signal line (29) . 6. A kind of sedimentation-prone water quality open channel flow meter according to claim 1, characterized in that: said hand-held terminal (26) is connected with the data processing main board (14) through the RS485 data communication line (17), for Make parameter settings. 7. A kind of easy sedimentation water quality open channel flow measuring instrument according to claim 2, is characterized in that: described photoelectric type mud thickness measuring part is combined with data processing main board (14) and is used for measuring water level, mud level position; The liquid impulsive force flow rate measurement part is combined with the data processing main board (14) to measure the flow rate of the water flow; the handheld terminal is used to set parameters. 8. according to claim 1 according to the measuring method of a kind of easy sedimentation water quality open channel flow measuring instrument according to claim 1, it is characterized in that described method step is: (1) Choose the location to install the instrument: choose a place where the channel is regular, the bottom of the channel is flat, and the water velocity before and after the installation location is relatively stable; (2) Record the installation parameters: adjust the bottom of the stress rod to be 3~5cm away from the bottom plate of the shell, and record the distance as the height of the stress rod; measure the width of the canal, the distance l ₁ from the rotating shaft to the stress point of the load cell, and the distance from the rotating shaft to the stress point The distance between the bottom of the force bar is l ₂ , and the width of the force bar is l _width ; (3) Install the instrument into the open channel: put the measuring device as a whole into the selected installation position, the bottom plate of the shell is in close contact with the bottom of the channel, and the water flows on the bottom plate of the shell, and along the direction of the water flow, first passes through the liquid impulse flow velocity measuring part, and then passes through Photoelectric silt thickness measurement components; (4) Determine the calibration flow rate: use the standard table method to measure the water velocity at the same cross-section of the bottom, middle, surface and force bar respectively, and obtain a relatively stable average value as the calibration flow rate; (5) Use the handheld terminal to set parameters: set the recorded parameters and calibrated flow rate into the data processing main board, and return to the current monitoring interface of the handheld terminal to observe the displayed data, including water level, mud level, temperature, flow, flow rate, momentum; (6) Data operation. According to the collected parameters and the parameters set by the user, the data processing board performs calculation and processing to obtain the final water level, mud level, temperature, flow rate, flow velocity and momentum. First of all, the data processing main board first calculates the water level, mud level and temperature. According to the signal collected by the temperature acquisition circuit, the data processing main board can directly calculate the temperature. According to the sampling value of the photoelectric silt thickness measuring part and the base value set by the user, the water level and mud level can be obtained; Secondly, according to the height of the stress rod set by the user, the actual depth h of the stress rod into the water (water level - height of the stress rod) is obtained; Third, calculate the initial force F ₀ . The data processing main board calculates the initial force F ₀ according to the pressure F _pressure on the load cell collected by the liquid impulse flow rate measurement part, as well as l ₁ , l ₂ , l _width , h, and calibration flow rate. The comprehensive calculation formula is: Fourth, calculate the flow velocity v. The data processing main board calculates the actual water flow velocity according to the above formula according to the pressure F _pressure on the load cell, and l ₁ , l ₂ , l _width , h, and initial force F ₀ ; Finally, calculate the traffic. Subtract the height of the mud level from the height of the water level to obtain the actual height of the cross-section without silt. According to the shape of the cross-section (trapezoidal, rectangular), calculate the accurate area of the cross-section. Combined with the calculated flow velocity, use the flow velocity-area The flow rate of the water flow can be obtained by the method: Q=vSt, where Q is the flow rate of the water flow, S is the cross-sectional area of the water, and t is the time. (7) Access to the hydrological monitoring system: use the RS485 communication line to connect the RS485 communication port of the measuring instrument to the RS485 communication interface of the hydrological monitoring system to build a communication line between the two, and the measuring instrument will upload the collected data to the hydrological monitoring System software, the user can see the water level, mud level, temperature, flow, flow velocity, momentum information on the real-time data interface of the hydrological monitoring system software. 4 -->