CN206683730U - A kind of ultrasonic flowmeter signal to noise ratio detects alarm module - Google Patents
A kind of ultrasonic flowmeter signal to noise ratio detects alarm module Download PDFInfo
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- CN206683730U CN206683730U CN201621479743.2U CN201621479743U CN206683730U CN 206683730 U CN206683730 U CN 206683730U CN 201621479743 U CN201621479743 U CN 201621479743U CN 206683730 U CN206683730 U CN 206683730U
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Abstract
The utility model belongs to field of flow measurement, a kind of more particularly to ultrasonic flowmeter signal to noise ratio detection alarm module, the signal source transmission signal enters the electronic analog swtich, the electronic analog swtich, the amplitude measurement unit, the single-chip microcomputer and the alarm output unit are sequentially connected, the single-chip microcomputer connects and controls the electronic analog swtich and alarm output unit, the signal enters amplitude measurement module by electronic analog swtich, the signal source includes noise signal source and ultrasonic signal source, the electronic analog swtich switching noise signal source and ultrasonic signal source, the single-chip microcomputer gathers the noise signal source of the amplitude measurement module measurement and the ultrasonic signal source sends noise signal and the amplitude of ultrasonic signal.The beneficial effects of the utility model：Can real-time detection signal-to-noise ratio, reflect flow meter applications environment noise level；Signal to noise ratio exceeds flowmeter tolerance limit, can trigger alarm, reminds Field Force's on-line checking.
Description
Technical field
The utility model belongs to field of flow measurement, more particularly to a kind of ultrasonic flowmeter signal to noise ratio detection alarm mould
Block.
Background technology
Ultrasonic flowmeter is by detecting effect of the flow of fluid to supersonic beam (or ultrasonic pulse) with measurement stream amount
Instrument.Ultrasonic flowmeter generally use time difference type measuring principle：One probe transmission signal passes through medium, opposite side tube wall
Afterwards, received by another probe, meanwhile, second same transmission signal of probe is received by first probe, due to by
The influence of velocity of medium, the two existence time is poor, and according to time difference and the corresponding relation of flow velocity, the flow velocity of flowmeter is calculated
Value.Learnt by the measuring principle of ultrasonic flowmeter, if correct ultrasonic signal can be obtained, be related to the stream measured
Whether value is accurate.But in industry spot, flowmeter is likely encountered many various interference, have the interference from power network,
There is space interference, also have interference of the various live sound sources to ultrasonic transducer, these disturbing reactions to ultrasound signal receipt
Be exactly noise in processing, if noise intensity exceed ultrasonic flowmeter tolerance limit, flowmeter will measuring error, output one
Individual wrong flow value.We commonly use the ratio of signal and noise in electronic equipment or electronic system, i.e. signal to noise ratio parameter is come
Noise is weighed whether beyond the patient limit of flowmeter institute.In general ultrasonic flowmeter only has flow measurement function, and
There is no signal to noise ratio detection function, so they can not judge that signal to noise ratio is above tolerance limit, whether flow measurement is normal.
Utility model content
For the above mentioned problem to be solved, the utility model provides a kind of ultrasonic flowmeter signal to noise ratio detection alarm module.
The technical solution of the utility model：A kind of ultrasonic flowmeter signal to noise ratio detects alarm module, it is characterised in that bag
Signal source, electronic analog swtich, amplitude measurement unit, single-chip microcomputer and alarm output unit are included, the signal source transmission signal is entered
Enter the electronic analog swtich, the electronic analog swtich, the amplitude measurement unit, the single-chip microcomputer and the warning output
Unit is sequentially connected, and the clock unit is connected with the single-chip microcomputer.
Preferably, the single-chip microcomputer connects and controls the electronic analog swtich and alarm output unit, and the signal leads to
Cross electronic analog swtich and enter amplitude measurement module, the signal source includes noise signal source and ultrasonic signal source, the electricity
Sub- analog switch switching noise signal source and ultrasonic signal source, the single-chip microcomputer gather the institute of the amplitude measurement module measurement
State noise signal source and the ultrasonic signal source sends noise signal and the amplitude of ultrasonic signal, set in the single-chip microcomputer
Threshold value comparing unit, the threshold value comparing unit are connected with the alarm output unit, the clock unit and the single-chip microcomputer
Connection produces the clock frequency needed for the single-chip microcomputer.
Preferably, the electronic analog swtich uses U1；The amplitude measurement unit includes diode D1, electric capacity C1, electricity
Resistance R1, resistance R2 and diode D1, the diode D1 negative poles meet the one of the electric capacity C1, the resistance R1 and the resistance R2
End, the diode D1 negative poles connect electric capacity C1, resistance R1 and resistance R2 one end, and the electric capacity C1 other ends are grounded GND,
The positive pole of another terminating diode D2 of resistance R1；The single-chip microcomputer uses U2；The alarm output unit uses Schmidt
NOT gate U3A, the clock unit use crystal oscillator X1.
Preferably, the ultrasonic signal source connects 1 pin of the electronic analog swtich U1, and the noise signal source meets institute
State electronic analog swtich U1 5 pin, 6 pin that 2 pin of the electronic analog swtich U1 connect the electronic analog swtich connect two poles again
Pipe D1 positive poles, 8 pin of the electronic analog swtich U1 meet power supply VCC, the electronic analog swtich U1 4 pin ground wire GND, institute
3 pin for stating electronic analog swtich U1 connect 14 pin of the single-chip microcomputer U2, and 7 pin of the electronic analog swtich U1 connect the monolithic
Machine U2 13 pin, diode D1 negative poles connect electric capacity C1, resistance R1 and resistance R2 one end, the electric capacity C1 other ends ground wire
GND, the positive pole of another terminating diode D2 of resistance R1, the diode D2 negative poles meet 12 pin of the single-chip microcomputer U2, institute
Resistance R2 another termination single-chip microcomputer U2 2 pin are stated, 1 pin and 64 pin of the single-chip microcomputer U2 connect power supply VCC, the list
Piece machine U2 8 pin and 9 pin meet crystal oscillator X1,62 pin of the single-chip microcomputer U2 and 63 pin ground wire GND, and the 48 of the single-chip microcomputer U2
Pin connects Schmidt's NOT gate U3A 1 pin, and 14 pin of Schmidt's NOT gate U3A meet power supply VCC, and the 7 of Schmidt's NOT gate U3A
Pin is grounded GND, the 2 pin output alarm signals of Schmidt's NOT gate U3A.
Preferably, the electronic analog swtich U1 uses model MAX4642EUA, and the frequency of the crystal oscillator X1 is
32768Hz, the single-chip microcomputer U2 use model MSP430F249, Schmidt's NOT gate U3A, model 74HC14
The utility model beneficial effect is：
1. it is simple in construction, it is reasonable in design, discharge many various interference；
2. can real-time detection signal-to-noise ratio, reflect flow meter applications environment noise level；
3. signal to noise ratio exceeds flowmeter tolerance limit, alarm is can trigger, reminds Field Force's on-line checking.
Brief description of the drawings
Fig. 1 is circuit structure diagram of the present utility model.
Fig. 2 is the circuit diagram of embodiment of the present utility model.
Embodiment
A kind of embodiment of the present utility model is explained below in conjunction with the accompanying drawings.
It the utility model is related to a kind of ultrasonic flowmeter signal to noise ratio detection alarm module, including signal source, electronic simulation
Switch, amplitude measurement unit, single-chip microcomputer and alarm output unit, the signal source transmission signal are opened into the electronic simulation
Close, the electronic analog swtich, the amplitude measurement unit, the single-chip microcomputer and the alarm output unit are sequentially connected, institute
Clock unit is stated to be connected with the single-chip microcomputer.
Preferably, the single-chip microcomputer connects and controls the electronic analog swtich and alarm output unit, and the signal leads to
Cross electronic analog swtich and enter amplitude measurement module, the signal source includes noise signal source and ultrasonic signal source, the electricity
Sub- analog switch switching noise signal source and ultrasonic signal source, the single-chip microcomputer gather the institute of the amplitude measurement module measurement
State noise signal source and the ultrasonic signal source sends noise signal and the amplitude of ultrasonic signal, set in the single-chip microcomputer
Threshold value comparing unit, the threshold value comparing unit are connected with the alarm output unit, the clock unit and the single-chip microcomputer
Connection produces the clock frequency needed for the single-chip microcomputer.
Preferably, the electronic analog swtich uses U1；The amplitude measurement unit includes diode D1, electric capacity C1, electricity
Resistance R1, resistance R2 and diode D1, the diode D1 negative poles meet the one of the electric capacity C1, the resistance R1 and the resistance R2
End, the diode D1 negative poles connect electric capacity C1, resistance R1 and resistance R2 one end, and the electric capacity C1 other ends are grounded GND,
The positive pole of another terminating diode D2 of resistance R1；The single-chip microcomputer uses U2；The alarm output unit uses Schmidt
NOT gate U3A clock units use crystal oscillator X1.Clock unit is for providing control sequential, accurate sequential to whole system
Control can just ensure the accuracy of signal acquisition, so this module employs external crystal-controlled oscillation as clock unit, it is desirable to crystal oscillator
Working frequency be less than 20ppm in 32768Hz, frequency stability.
Preferably, the ultrasonic signal source connects 1 pin of the electronic analog swtich U1, and the noise signal source meets institute
State electronic analog swtich U1 5 pin, 6 pin that 2 pin of the electronic analog swtich U1 connect the electronic analog swtich connect two poles again
Pipe D1 positive poles, 8 pin of the electronic analog swtich U1 meet power supply VCC, the electronic analog swtich U1 4 pin ground wire GND, institute
3 pin for stating electronic analog swtich U1 connect 14 pin of the single-chip microcomputer U2, and 7 pin of the electronic analog swtich U1 connect the monolithic
Machine U2 13 pin, diode D1 negative poles connect electric capacity C1, resistance R1 and resistance R2 one end, the electric capacity C1 other ends ground wire
GND, the positive pole of another terminating diode D2 of resistance R1, the diode D2 negative poles meet 12 pin of the single-chip microcomputer U2, institute
Resistance R2 another termination single-chip microcomputer U2 2 pin are stated, 1 pin and 64 pin of the single-chip microcomputer U2 connect power supply VCC, the list
Piece machine U2 8 pin and 9 pin meet crystal oscillator X1,62 pin of single-chip microcomputer U2 described in crystal oscillator X1 and 63 pin ground wire GND, the single-chip microcomputer
U2 48 pin connect Schmidt's NOT gate U3A 1 pin, and 14 pin of Schmidt's NOT gate U3A connect power supply VCC, Schmidt's NOT gate
U3A 7 pin ground wire GND, the 2 pin output alarm signals of Schmidt's NOT gate U3A.
Preferably, the electronic analog swtich U1 uses model MAX4642EUA, and the frequency of the crystal oscillator X1 is
32768Hz, the clock frequency of crystal oscillator X1 offer is higher, and the speed of service of that single-chip microcomputer is also faster.Single-chip microcomputer U2 uses type
Number MSP430F249, Schmidt's NOT gate U3A, the effect of model 74HC14 electronic analog swtich is for switching ultrasonic wave letter
Number and noise signal, requirements of type selecting conducting resistance be less than 10 ohm, switch time is less than 100ns；Single-chip microcomputer can select TI public
Take charge of MSP430 series 16 single-chip microcomputers of low-power consumption, it is desirable to which there are internal 12 AD conversion modules；The output delay of Schmidt's NOT gate is small
In 100ns, current driving ability is more than 3mA.
Embodiment 1
A kind of ultrasonic flowmeter signal to noise ratio detects alarm module, including signal source, electronic analog swtich, amplitude measurement list
Member, single-chip microcomputer, clock unit and alarm output unit, wherein signal enter electronic analog swtich, and electronic die is controlled by single-chip microcomputer
Intend switch, signal enters amplitude measurement module by electronic analog swtich, then, and calculates signal to noise ratio, is carried out with given threshold
Compare, if being less than threshold value, by alarm output module output alarm signal, remind Field Force's on-line checking, clock unit
The clock frequency needed for connection generation single-chip microcomputer is connected with single-chip microcomputer.
Single-chip microcomputer connects and controls electronic analog swtich and alarm output unit, and signal enters width by electronic analog swtich
It is worth measurement module, signal source includes noise signal source and ultrasonic signal source, and electronic analog swtich switching noise signal source is with surpassing
Acoustic signal source, the noise signal source of single-chip microcomputer collection amplitude measurement module measurement and ultrasonic signal source send noise signal with
The amplitude of ultrasonic signal, single-chip microcomputer is interior to set threshold value comparing unit, and threshold value comparing unit is connected with alarm output unit, clock
Unit is connected the clock frequency produced needed for the single-chip microcomputer with the single-chip microcomputer.
Electronic analog swtich uses U1；Amplitude measurement unit includes diode D1, electric capacity C1, resistance R1, resistance R2 and two
Pole pipe D1, diode D1 negative poles connect electric capacity C1, resistance R1 and resistance R2 one end, and diode D1 negative poles meet electric capacity C1, resistance R1
With resistance R2 one end, electric capacity C1 other ends ground wire GND, another terminating diode D2 of resistance R1 positive pole；Single-chip microcomputer uses
U2；Alarm output unit uses Schmidt NOT gate U3A, and clock unit uses crystal oscillator X1.
Electronic analog swtich U1, model MAX4642EUA, diode D1, diode D2, electric capacity C1, resistance R1, resistance R2,
Crystal oscillator X1, frequency 32768Hz, single-chip microcomputer U2, model MSP430F249, Schmidt NOT gate U3A, model 74HC14；Electronic simulation
Switch selects 4 ohm of MAX4642EUA conducting resistances, switch time 20ns；Single-chip microcomputer selects 16 single-chip microcomputers of TI companies
MSP430F249, internal 12 AD conversion modules of multichannel；Schmidt's NOT gate is 12ns from 74HC14 transmission delays, and electric current drives
Ability is more than+5mA.
Ultrasonic signal caused by ultrasonic signal source in signal source connects electronic analog swtich U1 1 pin, in signal source
Noise signal source caused by noise signal connect electronic analog swtich U1 5 pin, electronic analog swtich U1 2 pin connect 6 pin and connect two
Pole pipe D1 positive poles, electronic analog swtich U1 8 pin connect power supply VCC, electronic analog swtich U1 4 pin ground wire GND, electronic die
3 pin for intending switch U1U1 connect single-chip microcomputer U2 14 pin, and electronic analog swtich U1 7 pin connect U2 13 pin, and diode D1 negative poles connect
Electric capacity C1, resistance R1 and resistance R2 one end, electric capacity C1 other ends ground wire GND, another terminating diode D2 of resistance R1 are just
Pole, diode D2 negative poles connect single-chip microcomputer U2 12 pin, and the resistance R2 other end connects single-chip microcomputer U2 2 pin, single-chip microcomputer U2 1 pin and
64 pin meet power supply VCC, and single-chip microcomputer U2 8 pin and 9 pin meet crystal oscillator X1, and effects of the crystal oscillator X1 to single-chip microcomputer U2 is very big, and he combines
Circuit inside single-chip microcomputer, produces clock frequency necessary to single-chip microcomputer, and the execution of all instructions of single-chip microcomputer is all built upon
On the basis of this, single-chip microcomputer U2 62 and 63 pin meet GND, and single-chip microcomputer U2 48 pin meet Schmidt's NOT gate U3A 1 pin, Shi Mi
Special NOT gate U3A 14 pin meet power supply VCC, and Schmidt's NOT gate U3A 7 pin are connected wires GND, Schmidt NOT gate U3A2 pin output report
Alert signal.
The course of work is as follows：Single-chip microcomputer U2 controls electronic analog swtich U1, and ultrasonic signal is introduced into amplitude measurement module,
Single-chip microcomputer U2 12 pin are first set low into level, be delayed more than 5 μ s, then puts high level, and be delayed more than 100 μ s, passes through single-chip microcomputer U2
Internal AD conversion module reads the magnitude of voltage of 2 pin, obtains the amplitude V1 of ultrasonic signal, similarly, single-chip microcomputer U2 control electronics
Analog switch U1, noise signal is introduced into amplitude measurement module, U2 12 pin are first set low into level, be delayed more than 5 μ s, then puts height
Level, be delayed more than 100 μ s, and the magnitude of voltage of 2 pin is read by the AD conversion module inside single-chip microcomputer U2, obtains noise signal
Amplitude V2, signal to noise ratio snr, SNR=20Lg (V1/V2), then judge whether SNR is more than predetermined threshold value are calculated by formula
SNR0, single-chip microcomputer U2 controls 48 pin output low level if SNR is less than SNR0, high so as to be exported in Schmidt's NOT gate U3 2 pin
Level alarm signal, otherwise single-chip microcomputer U2 48 pin output high level, low level alarm signal is exported in Schmidt's NOT gate U3 2 pin
Number.It is achieved thereby that when noise signal exceeds tolerance limit, signal to noise ratio detection alarm module can export high level report
It is alert.
Compared with prior art, the technical program is simple in construction, reasonable in design, discharges many various interference；Can
Real-time detection signal-to-noise ratio, reflect the noise level of flow meter applications environment；Signal to noise ratio exceeds flowmeter tolerance limit, can trigger report
It is alert, remind Field Force's on-line checking.
An example of the present utility model is described in detail above, but content is only of the present utility model preferably real
Apply example, it is impossible to be considered as being used to limit practical range of the present utility model.All equalizations made according to present utility model application scope
Change and improvement etc., all should still be belonged within patent covering scope of the present utility model.
Claims (4)
1. a kind of ultrasonic flowmeter signal to noise ratio detects alarm module, it is characterised in that including signal source, electronic analog swtich, width
Value measuring unit, single-chip microcomputer, clock unit and alarm output unit, the signal source transmission signal are opened into the electronic simulation
Close, the electronic analog swtich, the amplitude measurement unit, the single-chip microcomputer and the alarm output unit are sequentially connected, institute
Clock unit is stated to be connected with the single-chip microcomputer.
A kind of 2. ultrasonic flowmeter signal to noise ratio detection alarm module according to claim 1, it is characterised in that the list
Piece machine connects and controls the electronic analog swtich and alarm output unit, and the signal enters amplitude by electronic analog swtich
Measurement module, the signal source include noise signal source and ultrasonic signal source, the electronic analog swtich switching noise signal
Source and ultrasonic signal source, the single-chip microcomputer gather the noise signal source of the amplitude measurement module measurement and the ultrasound
Ripple signal source sends noise signal and the amplitude of ultrasonic signal, and threshold value comparing unit, the threshold value are set in the single-chip microcomputer
Comparing unit is connected with the alarm output unit, and the clock unit is connected with the single-chip microcomputer to be produced needed for the single-chip microcomputer
Clock frequency.
A kind of 3. ultrasonic flowmeter signal to noise ratio detection alarm module according to claim 2, it is characterised in that the electricity
Sub- analog switch uses U1；The amplitude measurement unit includes diode D1, electric capacity C1, resistance R1, resistance R2 and diode D2,
The diode D2 negative poles connect the electric capacity C1, the resistance R1 and the resistance R2 one end, and the diode D1 negative poles connect
Electric capacity C1, resistance R1 and resistance R2 one end, the electric capacity C1 other ends are grounded GND, two poles of another terminations of resistance R1
Pipe D2 positive pole；The single-chip microcomputer uses U2；The alarm output unit uses Schmidt's NOT gate U3A, and the clock unit is adopted
With crystal oscillator X1.
4. a kind of ultrasonic flowmeter signal to noise ratio detection alarm module according to claim 3, it is characterised in that described super
Acoustic signal source connects 1 pin of the electronic analog swtich U1, and the noise signal source connects the 5 of the electronic analog swtich U1
Pin, 6 pin that 2 pin of the electronic analog swtich U1 connect the electronic analog swtich connect diode D1 positive poles, the electronic die again
Intend switch U1 8 pin connect power supply VCC, the electronic analog swtich U1 4 pin ground wire GND, the 3 of the electronic analog swtich U1
Pin connects 14 pin of the single-chip microcomputer U2, and 7 pin of the electronic analog swtich U1 connect 13 pin of the single-chip microcomputer U2, the diode
D2 negative poles meet 12 pin of the single-chip microcomputer U2, another termination single-chip microcomputer U2 of the resistance R2 2 pin, the single-chip microcomputer U2
1 pin and 64 pin connect power supply VCC, the single-chip microcomputer U2 8 pin and 9 pin and connect crystal oscillator X1, the single-chip microcomputer U2 62 pin and 63 pin
GND is grounded, 48 pin of the single-chip microcomputer U2 connect Schmidt's NOT gate U3A 1 pin, and 14 pin of Schmidt's NOT gate U3A connect electricity
Source VCC, Schmidt's NOT gate U3A 7 pin ground wire GND, the 2 pin output alarm signals of Schmidt's NOT gate U3A；
The electronic analog swtich U1 is described using model MSP430F249 using model MAX4642EUA, the single-chip microcomputer U2
Schmidt NOT gate U3A, model 74HC14, the crystal oscillator X1 frequency are 32768Hz.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201621479743.2U CN206683730U (en) | 2016-12-30 | 2016-12-30 | A kind of ultrasonic flowmeter signal to noise ratio detects alarm module |
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| CN201621479743.2U CN206683730U (en) | 2016-12-30 | 2016-12-30 | A kind of ultrasonic flowmeter signal to noise ratio detects alarm module |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106768205A (en) * | 2016-12-30 | 2017-05-31 | 天津市迅尔仪表科技有限公司 | A kind of ultrasonic flowmeter signal to noise ratio detects alarm module |
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- 2016-12-30 CN CN201621479743.2U patent/CN206683730U/en active Active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106768205A (en) * | 2016-12-30 | 2017-05-31 | 天津市迅尔仪表科技有限公司 | A kind of ultrasonic flowmeter signal to noise ratio detects alarm module |
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