CN2779398Y - Transmitter for measuring gas concentration of sulfur hexafluoride - Google Patents

Abstract

The utility model relates to a transmitter for measuring concentration of sulfur hexafluoride gas, which is provided with an ultrasonic detecting device, a monolithic computer and an environmental parameter collecting circuit, wherein the ultrasonic detecting device is provided with a waveform generator, an amplifying and isolating circuit, a sampling device, a referencing device, an isolating, amplifying and shaping circuit, a comparing filter, a measuring filter, a frequency divider and a crystal oscillating circuit; the environmental parameter collecting circuit is provided with a temperature collecting circuit. The transmitter of the utility model has the advantages of simple structure and high safety, can carry out real-time measurement on the spot, and can carry out real-time measurement on the sulfur hexafluoride of low concentration, and the precision of the measurement is high.

Description

Measure the transmitter of sulfur hexafluoride gas concentration

Technical field

The utility model relates to a kind of transmitter of measuring sulfur hexafluoride gas concentration.

Background technology

Sulfur hexafluoride (SF ₆) be to have the remarkable electrical insulating property and the gas of arc quenching characteristic.In power industry, sulfur hexafluoride is widely used in the electrical equipment, and as power switch, enclosed capacitor group, transformer etc., these electrical equipments that contain sulfur hexafluoride the leakage of sulfur hexafluoride gas occurs sometimes in the process of operation.Because sulfur hexafluoride gas proportion is bigger than air, accumulate in after the leakage in the room and make low sheaf space anoxic, the people is suffocated; The sulfur hexafluoride gas that was shocked by electricity by electric arc also can produce poisonous and hazardous analyte, and equipment is caused corrosion.At the threat of sulfur hexafluoride electrical equipment site environment to human health, the relevant laws rules and regulations must be installed the monitoring and the warning system that exceeds standard in corresponding power distribution equipment chamber.

On physical property, under the sulfur hexafluoride normality a kind of colourless, tasteless, nontoxic nonflammable gas, proportion is about 5 times of air.On chemical property, its chemical composition stability has fabulous thermal stability.Therefore then easy unlike detecting oxygen or carbon dioxide if adopt chemical sensor to detect sulfur hexafluoride gas concentration.The method of at present adopted measurement sulfur hexafluoride gas concentrations mostly is physical method, as: vapor-phase chromatography, coefficient of heat conductivity method, electron drift method, optical interferometry, ultrasonic Method for Measuring etc.4 kinds of methods of front not only need expensive instrument and equipment, and require the operator to have quite high operant level, therefore popularize quite difficulty.The ultrasonic measurement rule has equipment cost advantage lower, simple to operate.The principle that adopts ultrasonic Method for Measuring to measure binary mixture is: because the ultrasonic velocity of propagating in sample gas can be expressed as the mean molecular weight of sample gas and the function of temperature, and if sample gas is when being binary mixture, as long as determine the ultrasonic propagation velocity in the sample gas and the temperature of sample gas, just can be in the hope of the mean molecular weight of sample gas, and then can calculate the concentration of any gas in the sample gas thus.

Binary mixture can be regarded as ideal gas at normal temperatures and pressures, and ultrasound wave is to propagate in gas with the very high-speed small amplitude motion of doing, and its process can be regarded as adiabatic process.The velocity of sound can be expressed as in the ideal gas:

c＝(γRT/M) ^1/2 (1)，

Wherein, R=8.31JMOl ^-1K ^-1Be gas law constant, T is absolute gas temperature, and γ is the ratio of gas specific heat at constant pressure and specific heat at constant volume, and M is the quality of a moles of gas.For binary mixture,

$\stackrel{\‾}{\mathrm{\γ}}=\frac{{\mathrm{nC}}_{\mathrm{va}}+(1-n)C_{\mathrm{vb}}}{{\mathrm{nC}}_{\mathrm{Pa}}+(1-n)C_{\mathrm{Pb}}},$ M＝nM _a+(1-n)M _b，

A, b represent object gas and background gas respectively, and n is the concentration of gas a, and 1-n is the concentration of gas b, C _VaAnd C _VbBe respectively the specific heat at constant volume of gas a, b, C _PaAnd C _PbBe respectively the specific heat at constant pressure of gas a, b, and C is arranged _Vi=C _Pi-R _O, i represents a, b.

The two-way same-phase that transmits, then two-way phase of received signal difference θ is:

C ₁Be the velocity of sound in finite concentration a and the b mixed gas, C ₂Be the velocity of sound in the single b gas, f is the sound pulse frequency.Wushu (1) is brought in (2), and makes L 1 can get:

" the A Sonar-Based Technique for the Ration-metric Determination of Binary GasMixtures " that the 219th page of 1988 " Nuclear Instruments and Methods in Physics Research " (research in the physics field of nuclear device and method thereof) of publishing are delivered to 234 pages of G.Hallewell that published Stanford Univ USA etc. (based on the quantitative measurement technology of the binary mixture of a sonar technique) literary composition, " Sensorsand Actuators " sensor and driver of publishing in 1993) " acoustic technique " the 105th page to 108 pages Yan Yushun that publish Tongji University that " AnUltrasonic Sensor for the Analysis of Binary Gas Mixtures " (a kind of ultrasonic sensor that detects binary mixture) that Joos R.N etc. delivers and nineteen ninety-five publish have been published for the 413rd page to 419 pages, old also cuckoo, " the theoretical and application of ultrasonic analysis binary mixture concentration " that Tang Jianming delivers, above-mentioned 3 documents all disclose a kind of method that adopts the ultrasonic pulse interval method to measure mixed gas concentration, its method is: first, the ultrasonic transducer of a pair of fixed range is set in combination gas to be measured, from a transducer to another transducers transmit ultrasonic waves pulse, measure the time that ultrasonic pulse is propagated, and then calculate the velocity of propagation of ultrasound wave in gas to be measured; The second, measures ambient temperature, the 3rd, extrapolate the concentration of gas according to the funtcional relationship between ultrasonic velocity, environment temperature and the gas medium blending ratio three.The weak point of this method is: measuring accuracy is not high enough, can not satisfy and detect low concentration SF ₆The requirement of gas.

That Chinese patent application 02800155.9 discloses is a kind of " utilizing the device and method of the flow of oxygen concentration in the ultrasonic measuring sample gas and this sample gas ", when carrying out the measurement of gas concentration, successively in same passage, import calibration gas and sample gas and record the velocity of propagation of ultrasound wave successively, calculate the concentration value of sample gas then according to the calculating formula relevant with the velocity of sound at calibration gas and sample gas; But the efficient of this measuring method is lower, and can not measure in real time, is difficult to popularize in commercial Application; Simultaneously, its measuring accuracy is high not enough, can not satisfy the requirement of the sulfur hexafluoride that detects light concentration gas such as low concentration.Chinese patent application 03112800.9 discloses a kind of " method of difference ultrasonic gas trace changes mensuration and control evaluating system ", this application adopts two passages, a passage seals at the scene, what it touched is still unchanged gas, another passage blow-by, little change gas makes the velocity of sound produce little change at this.During work, two channel temperatures are identical, and temperature-responsive is also identical, subtract each other by two paths of signals behind the difference channel, the information that last output-response gas content changes.Accurate tracking performance and the technical complexity but this application points out that phase-locked loop that it adopts has uniqueness, and this application is not illustrated the tracing property and the technical complexity of this uniqueness precision, so those of ordinary skill in the art can't implement.Chinese patent application 200320100440.1 discloses " a kind of device that is used for transformer station's High-Voltage Electrical Appliances detection sulfur hexafluoride gas ", this application adopts the gas in the continuous suction environment of gas suction device, make it to enter the sound wave comparer, the output signal of sound wave comparer enters signal processor, and signal processor is calculated sulfur hexafluoride gas concentration again.In this application, has only a gas suction device, but openly in the sound wave comparer relatively be which gas or the comparison of sound wave comparer what is, sound wave generating device and receiving trap are not disclosed yet, the a series of problems such as circuit theory diagrams what signal is signal processor handle and realize this application are not disclosed yet, so can't implement the scheme of this application for those of ordinary skill in the art at all.

The utility model content

The purpose of this utility model provides a kind of simple in structure, safety, can be to the transmitter of the measurement sulfur hexafluoride gas concentration that the low concentration sulfur hexafluoride is measured in real time and precision is higher.

Realize that a kind of technical scheme that transmitter adopted of measuring sulfur hexafluoride gas concentration that provides in the utility model purpose is, this transmitter has ultrasonic detection device, and ultrasonic detection device has sampling apparatus and comparable device; End as transmitting terminal of sampling apparatus and comparable device inside is equipped with the hyperacoustic ultrasonic transducer of emission, is equipped with as the other end of receiving end and receives hyperacoustic ultrasonic transducer; It is characterized in that: also have single-chip microcomputer and environmental parameter Acquisition Circuit; Ultrasonic detection device also has waveform generator, amplifies buffer circuit, isolates amplification and rectification circuit, relatively reaches and measure wave filter, frequency divider and crystal oscillating circuit; The crystal oscillator signal output part of crystal oscillating circuit connects frequency divider; Frequency divider has two output terminals, exportable first frequency f when being to use respectively ₁First frequency output terminal and exportable second frequency f when using ₂The second frequency output terminal, described first frequency f ₁In the frequency of ultrasonic scope, described second frequency f ₂Be first frequency f ₁50 to 300 times; The input end of the first frequency output terminal welding wave generator of frequency divider, its second frequency output termination relatively reaches the frequency signal input end of measuring wave filter; The output termination of waveform generator is amplified buffer circuit, the output terminal while of amplifying buffer circuit is electrically connected with the power end of the ultrasonic transducer at the transmitting terminal place of sampling apparatus and comparable device, and the output terminal of the ultrasonic transducer at the receiving end place of sampling apparatus and comparable device is electrically connected with the input end of corresponding isolation amplification and rectification circuit separately; Each is isolated the output terminal of amplification and rectification circuit and is electrically connected with the respective input that relatively reaches 2 ultrasonic measurement signals measuring wave filter, relatively reaches the ultrasonic measurement signal data of the ultrasonic measurement signal data of measurement wave filter and control end and single-chip microcomputer and control end is two-way is electrically connected; The environmental parameter Acquisition Circuit has temperature collection circuit; The temperature signal output terminal of temperature collection circuit links to each other with the temperature signal input end of analog to digital conversion circuit electricity, and the data of analog to digital conversion circuit and control end link to each other with the first environment supplemental characteristic and the two-way electricity of control end of single-chip microcomputer; Single-chip microcomputer is variable and can calculate sulfur hexafluoride gas concentration according to corresponding formula with ultrasonic measurement signal and temperature signal in use.

In the technique scheme, hyperacoustic transducer of the emission of sampling apparatus and the distance that receives between hyperacoustic transducer are equal to the hyperacoustic transducer of emission of comparable device and the distance between the hyperacoustic transducer of reception; Comparable device and sampling apparatus all are that a shell is tubular and by being arranged on the device that 2 on the tubular shell communicates with extraneous air to 6 micropores; The hyperacoustic ultrasonic transducer of the emission of comparable device and sampling apparatus is separately positioned on an end of corresponding tubular shell inside, and the hyperacoustic ultrasonic transducer of the reception of comparable device and sampling apparatus is separately positioned on the other end of corresponding tubular shell inside.

In the technique scheme, comparable device is 2 to 5 meters directly over sampling apparatus.

In the technique scheme, the environmental parameter Acquisition Circuit also has oxygen level Acquisition Circuit and humidity Acquisition Circuit, the oxygen content signal output terminal of oxygen level Acquisition Circuit links to each other with the oxygen content signal input end of D/A converting circuit, and the moisture signal output terminal of humidity Acquisition Circuit links to each other with the moisture signal input end of single-chip microcomputer; Single-chip microcomputer also has control signal output ends, when this control signal output ends is to use under the situation that the sulfur hexafluoride gas concentration value exceeds standard or humidity value exceeds standard or the oxygen content value is not up to standard, the port of exportable fan starting control signal and/or alarm control signal; This transmitter also has the RS-485 serial port circuit, the serial data of the serial data of single-chip microcomputer and control end and RS-485 serial port circuit and control end is two-way is electrically connected.

In the technique scheme, relatively reach the measurement wave filter and have window comparator, digit phase calculating device and digital filter; 2 input ends of window comparator are and relatively reach 2 ultrasonic measurement signal input parts measuring wave filter, the output termination digital phasemeter of window comparator is calculated the ultrasonic measurement signal input part of device, digit phase calculates the input end of the output termination digital filter of device, and the ultrasonic measurement signal data of digital filter and control end are and relatively reach ultrasonic measurement signal data and the control end of measuring wave filter.

In the technique scheme, frequency divider, waveform generator and relatively reach and measure wave filter and be arranged in the complex programmable logic device (CPLD).

The utlity model has positive effect: the method for (1) measurement sulfur hexafluoride gas concentration that transmitter of the present utility model adopted is the phase differential point-score, and provide concrete embodiment, no phase-locked loop road in the variator of the present utility model, but utilize frequency splitting technology, by the electric pulse of frequency divider output two-way different frequency, they are first frequency electric pulse and second frequency electric pulse; The frequency of first via electric pulse is corresponding with ultrasonic frequency, and the frequency of the second road electric pulse is tens of times to hundreds of times of first via electrical impulse frequency; First via electric pulse is divided into two-way again, one the tunnel makes sampling apparatus produce the ultrasound wave of first frequency, another road makes comparable device produce the ultrasound wave of first frequency simultaneously, after this two-way ultrasound wave is received by corresponding ultrasonic transducer and converted to electric signal, measure wave filter and carry out the phase bit comparison through isolating to amplify to transport to relatively to reach respectively; The second road electric pulse transport to relatively reach measure frequency behind the wave filter be first via electrical impulse frequency doubly, be compared and measure wave filter in order to carry out the measurement of phase differential as the scaled measurement unit of measure phase difference, resulting measurement result is delivered to single-chip microcomputer, again by single-chip microcomputer according to this measurement result and the temperature parameter that received, calculate the concentration of sulfur hexafluoride according to corresponding formula, according to different concentration numerical value, single-chip microcomputer is exported accordingly.Therefore, transmitter of the present utility model be a kind of can be to the device that concentration is measured in real time and precision is higher of the sulfur hexafluoride at scene, and practicality is stronger.(2) because the phase change of sound wave is taken from detection of the present utility model sampling, therefore not only measure the precision height of minimum gas concentration, the dynamic range of measure gas concentrations is big simultaneously.By relevant regulations, work as SF ₆When gas concentration reaches 1000PPM, must report to the police.And transmitter precision of the present utility model can reach 50PPM, and is safe and reliable.(3) transmitter of the present utility model at work the waveform of its ultrasonic signal be that dutycycle is 1: 1 a continuous square wave, select the ultrasound wave of this waveform can stop standing wave and disturb good stability.(3) can carry out digital filtering and handle relatively reaching the measurement result of measuring the phase differential that wave filter exports when the utility model, and measuring accuracy is improved.(4) relatively reaching in the variator of the present utility model measured wave filter, frequency divider and waveform generator and can be arranged in the programmable logic device (CPLD) of a complexity, and multiple function is combined in same chip, be easy to advantages such as modification, expansion, online in real time are measured, antijamming capability is strong.(5) the automaticity height of transmitter of the present utility model, response time is short, can measure in real time at the scene, also can be provided with in addition at the scene and can be subjected to transmission controlled blower fan of the present utility model, thereby under tight situation, can pass through the Single-chip Controlling fan starting, improve security and reliability.

Description of drawings

Fig. 1 measures the theory diagram of the transmitter of sulfur hexafluoride gas concentration for the utility model.

Fig. 2 is the program flow chart of the single-chip microcomputer among Fig. 1.

Fig. 3 is the measurement SF based on the RS-485 network with the utility model transmitter ₆The monitoring system device block diagram of gas concentration.

Fig. 4 is the process flow diagram that the master controller among Fig. 3 is called out the single-chip microcomputer in the transmitter.

Fig. 5 is the program flow chart that the transmitter response master controller of the present utility model serial among Fig. 3 is interrupted.

Fig. 6 is that the master controller among Fig. 3 receives the variator data, the program flow chart that response keyboard interrupt and host computer interrupt.

Fig. 7 is the circuit theory diagrams of temperature collection circuit, humidity Acquisition Circuit, oxygen amount Acquisition Circuit, single-chip microcomputer and RS-485 interface driving circuit in the environmental parameter Acquisition Circuit in the transmitter of the present utility model.

Fig. 8 is the circuit theory diagrams of the ultrasonic detection device in the transmitter of the present utility model.

Fig. 9 is the circuit theory diagrams of master controller, RS-485 serial port circuit and RS-232 serial port circuit among Fig. 3.

Embodiment

(transmitter of embodiment 1, measurement sulfur hexafluoride gas concentration)

See Fig. 1, the transmitter of the measurement sulfur hexafluoride gas concentration of present embodiment has single-chip microcomputer 21, ultrasonic detection device 22, environmental parameter Acquisition Circuit 23 and RS-485 serial port circuit 24.

See Fig. 7, label is that the model of the single-chip microcomputer 21 of U10 is AT89C51, and single-chip microcomputer U10 is a kind of low-power consumption, high performance CMOS 8-bit microcomputer, and it has the erasable ROM (read-only memory) (EPROM) of 8k electricity able to programme.The port P00 to P07 of single-chip microcomputer 21, port READ and port WRITE are its ultrasonic measurement signal data and control end; The port P10 to P13 of single-chip microcomputer (21) is its first environment supplemental characteristic and control end; The T1 end of single-chip microcomputer (21) is the moisture signal input end; The RXD end of single-chip microcomputer U10, TXD end, P23 end and P27 end are its serial data and control end.21 pin of U10 are control signal and/or alarm signal output ends.

Still see Fig. 1, ultrasonic detection device 22 has waveform generator 22-1, amplification buffer circuit 22-2, sampling apparatus 22-3, comparable device 224, isolates amplification and rectification circuit 22-5, relatively reaches and measure wave filter 226, frequency divider 227 and crystal oscillating circuit 228.Wherein, frequency divider 22-7, waveform generator 22-1 and relatively reach and measure wave filter 22-6 and be arranged in the complex programmable logic device (CPLD) 22-10.

Relatively reach measurement wave filter 22-6 and have window comparator 22-6-1, digit phase calculating device 22-6-2 and digital filter 22-6-3; 2 input ends of window comparator 22-6-1 are and relatively reach 2 ultrasonic measurement signal input parts measuring wave filter 22-6, the output termination digital phasemeter of window comparator 22-6-1 is calculated the ultrasonic measurement signal input part of device 22-6-2, digit phase calculates the input end of the output termination digital filter 22-6-3 of device 22-6-2, and the output terminal of digital filter 22-6-3 is and relatively reaches ultrasonic measurement signal data and the control end of measuring wave filter 22-6.

The crystal oscillator signal input part that the crystal oscillator signal output part of crystal oscillating circuit 22-8 connects frequency divider 227 is 9 pin of CPLD U13; Frequency divider 22-7 has two output terminals, exportable first frequency f when being to use respectively ₁First frequency output terminal and exportable second frequency f when using ₂The second frequency output terminal, described first frequency f ₁In the frequency of ultrasonic scope, described second frequency f ₂Be first frequency f ₁100 times (they can be 50 times, 150 times, 200 times, 250 times or 300 times in other embodiments); The input end of the first frequency output terminal welding wave generator 22-1 of frequency divider 22-7, its second frequency output termination relatively reaches the frequency signal input end of measuring wave filter 226; The output terminal of waveform generator 221 is that 9 pin of CPLD U13 connect the input end that amplifies buffer circuit 222.

CPLD (complex programmable logic controller) is made of fully programmable and gate array and macroelement.With/or array be programmable, can realize multiple logic function; Not only can realize conventional logical device function, also can realize complicated sequential logic function.Macroelement then is can realize making up or the functional module of sequential logic, also provide simultaneously the output of true value or complement code with different extra dirigibilities such as path feedback.CPLD is applied to built-in applied system, combines, more can embody it, improved the performance of built-in applied system in system programmable, flexible characteristic easy to use with single-chip microcomputer.CPLD links to each other with single-chip microcomputer, can be used as a peripheral hardware of single-chip microcomputer, realizes the desired function of single-chip microcomputer.In the bit comparison of ultrasound wave phase, because ultrasonic frequency is 40kHz, and the phase differential accuracy requirement is very high in the phase bit comparison, be that hyperacoustic phase differential samples with common single-chip microcomputer be far from being enough, therefore adopted programmable logic device (CPLD) U13 with abundant programmable I/O pin, after CPLD U13 gathers the ultrasonic measurement signal and handles, the signal after handling is transported to the ultrasonic signal input end of single-chip microcomputer U10, realized the single-chip microcomputer function expansion.

See Fig. 8, the data of CPLD U13 and control end have D0, D1, D2, D3, D4, D5, D6, D7, READ and WRITE end, connect D0, D1, D2, D3, D4, D5, D6, D7, READ and the WRITE end of single-chip microcomputer U10 respectively.Light emitting diode D3 is a power light.HEADER 6 for meet the JTAG standard, be used for the connector lug that downloads at CPLD U13.

Still see Fig. 8, it is ultrasound transmitting transducer J6 that a end as transmitting terminal of sampling apparatus 22-3 and comparable device 22-4 inside is equipped with the hyperacoustic ultrasonic transducer of emission, is equipped with as the other end of receiving end that to receive hyperacoustic ultrasonic transducer be ultrasound wave receiving transducer J7.Hyperacoustic transducer of the emission of sampling apparatus 22-3 and the distance that receives between hyperacoustic transducer are equal to the hyperacoustic transducer of emission of comparable device 22-4 and the distance between the hyperacoustic transducer of reception; Comparable device 22-4 and sampling apparatus 22-3 all be a shell be tubular and by be arranged on 4 diameters on the tubular shell be the device that communicates with extraneous air of 1 millimeter hole (in other embodiments, hole on the shell can be 2,3,5 or 6, and the aperture can be 0.5 millimeter or 1.5 millimeters); The hyperacoustic ultrasonic transducer J6 of the emission of comparable device 22-4 and sampling apparatus 22-3 is separately positioned on an end of corresponding tubular shell inside, and the hyperacoustic ultrasonic transducer J7 of the reception of comparable device 22-4 and sampling apparatus 22-3 is separately positioned on the other end of corresponding tubular shell inside.Comparable device (22-4) directly over sampling apparatus (22-3) 3 meters (in other embodiments, can be 2 meters or 4 meters or 5 meters) is located.

See Fig. 8, isolating amplifier circuit 22-2 mainly is made up of triode Q1, Q2, transformer T1, resistance R 13, R14, R98, R99 and capacitor C 99, C16, C14.One end of capacitor C 14 links to each other with the base stage of triode Q2, and the other end of capacitor C 14 is the input end that amplifies buffer circuit 222.The output terminal of transformer T1 is the output terminal that amplifies buffer circuit 22-2.

The output terminal that amplifies buffer circuit 22-2 connects power end 1 pin and 3 pin of ultrasonic transducer J6 at the transmitting terminal place of sampling apparatus 223 and comparable device 224 simultaneously, and output terminal 1 pin of the ultrasonic transducer J7 at the receiving end place of sampling apparatus 22-3 and comparable device 224 and 3 pin connect the isolation amplification and rectification circuit 22-5-1 that isolates among the amplification and rectification circuit 22-5 and the input end of 22-5-2 respectively.Isolating amplification and rectification circuit 22-5 is made up of operational amplifier LM356, operational amplifier NE5532, comparer LM393 and capacitance C17, C18, C19, C20, C100, C101.Operational amplifier LM356, operational amplifier NE5532 and comparer LM393 are three integrated packages.3 pin of operational amplifier LM356 and 5 pin connect the negative pole of capacitance C100 and C101 respectively, and the positive pole of capacitance C100 and C101 is the input end of isolating amplification and rectification circuit 22-5-1 and 22-5-2.Connect 2 pin of operational amplifier NE5532 after the 1 pin serial connection capacitor C 17 of operational amplifier LM356, the resistance R 39, connect 6 pin of operational amplifier NE5532 after the 7 pin serial connection capacitor C 19 of operational amplifier LM356, the resistance R 40; Connect 1 pin and 7 pin of comparer LM393 behind 1 pin of operational amplifier NE5532 and 7 pin serial connection capacitor C 18 and the C20 respectively.It is 7 pin and 5 pin of CPLD U13 that the output terminal OBJ of isolation amplification and rectification circuit 22-5-1 and the output terminal REF of 22-5-2 connect the respective input that relatively reaches 2 ultrasonic measurement signals measuring wave filter 226 respectively.

Environmental parameter Acquisition Circuit 23 has temperature collection circuit 23-1, oxygen level Acquisition Circuit 23-2, humidity Acquisition Circuit 23-3 and analog to digital conversion circuit 23-4.

See Fig. 7, temperature collection circuit 23-1 is that humidity sensor U6, filter capacitor C28 and the resistance R 68 of LM35 formed by model.LM35 humidity sensor U6 is accurate integrated circuit temperature sensor, and output voltage and the celsius temperature scale of its output end vo ut are linearly proportional.1 pin of humidity sensor U6 connects+the 5V power supply, and 3 pin ground wires, 2 pin are the moisture signal output terminal, is serially connected between 2 pin of ground wire and humidity sensor U6 behind filter capacitor C28 and resistance R 68 polyphones.2 pin of the temperature signal output terminal U6 of temperature collection circuit 23-1 connect 1 pin of the temperature signal input end U8 of analog to digital conversion circuit 23-4.

Oxygen level Acquisition Circuit 23-2 is that oxygen level detecting sensor P2, comparer NE5532, filter capacitor C22, C1 and resistance R 49, R50, R51, the R3 of BNC forms by model.Resistance R 3 and capacitor C 1 formed the RC delay loop, and output terminal 1 pin of a termination comparer NE5532 of this RC delay loop connects the output terminal of sensor P2, the earth terminal ground wire of sensor P2 behind the other end series resistor R49 of this RC delay loop; Capacitor C 22 and resistance R 50 formed the RC delay loops, a termination ground wire of this RC delay loop, the positive input of another termination comparer NE5532, resistance R 51 be connected on comparer NE5532 positive input and+the 5V power end between.Output terminal 1 pin of comparer NE5532 connects input end of analog signal 2 pin of analog-digital conversion ic U8 as the signal output part of oxygen level Acquisition Circuit 23-2.

Humidity Acquisition Circuit 23-3 is one 555 astable circuit, be also referred to as multivibrator, this 555 astable circuit by model be the 555 timer U14 of LM555H, the model that changes capacitance size according to ambient humidity is that relative humidity sensor C15 and resistance R 1, R2, R4, the R11 of HS1100 forms; Wherein, the TRIG that C15 is serially connected in 555 integrated circuit U14 holds between 2 pin and the ground wire, and the TRIG of 555 integrated circuit U14 holds 2 pin and THR to hold 6 pin to link to each other; The output Q of moisture signal holds the Timer end T1 that meets single-chip microcomputer U10 behind the 3 pin series resistor R11 to hold 15 pin.Resistance R 4 is serially connected between 5 pin of ground wire and 555 integrated circuit U14; Be connected on after resistance R 1 and the R2 serial connection ground wire and 555 integrated circuit U14+the 5V power supply between, the contact of resistance R 1 and R2 connects 7 pin of 555 integrated circuit U14; 4 pin, 8 pin of 555 integrated circuit U14 connect+the 5V power supply, the 1 pin ground wire of 555 integrated circuit U14.The 6 pin THR end of 555 integrated circuit U14 is the threshold values end, 2 pin TRIG end is trigger end, and the 7 pin DIS end of 555 integrated circuit U14 is the output terminal of its inner triode for discharge end, conducting is arranged this triode and by two states, this state is by the magnitude of voltage decision of input end 6 pin.The 4 pin R end of U14 is reset terminal.The 5 pin CVolt end of U14 is the control voltage end, can change triggering level value up and down with it.The 3 pin Q end of U14 is that the moisture signal output terminal of humidity Acquisition Circuit 23-3, this output terminal connect moisture signal input end 15 pin of single-chip microcomputer 21; 3 pin of U14 have temporary stable state 0 and temporary 1 two kinds of output states of stable state.Back power supply+the 5V that powers on charges charging rate τ=(R to capacitor C 15 through resistance R 1, R2 ₁+ R ₂) C ₁₅The voltage of 6 foots begins to rise during charging, when 3.33V, and 7 pin conductings and discharging, making the output of Q end is low level temporary stable state 0 by temporary stable state 1 saltus step of high level; The voltage of 6 foots begins to descend, when 1.67V, 7 pin by, making the output of Q end is low level temporary stable state 1 by temporary stable state 0 saltus step of high level; No matter the Q end is output as 1 still is 0, and so going round and beginning again has formed the mutual conversion of 2 temporary stable states, obtains continuous square-wave signal output at output terminal.The frequency of this square wave is:

$f=\frac{1.43}{(R_1+{2R}_2){\mathrm{<figure-callout\; id="15"\; label="C"\; filenames="Y20052006940300241.png,Y20052006940300251.png"\; state="\{\{state\}\}">C</figure-callout>}}_{15}}$

Determine by the variable C15 of capacitance by obvious this output frequency as can be known of above-mentioned formula.So the frequency signal of Q end output is represented the humidity information of humidity Acquisition Circuit 23-3 place environment.

Analog to digital conversion circuit 23-4 is the analog-digital conversion ic U8 of TLC2543 by model and forms with reference to mu balanced circuit.Form by three-terminal voltage-stabilizing diode TC431, resistance R 31, R32, R35 and filter capacitor C9 with reference to mu balanced circuit.One termination ground wire of capacitor C 9, the other end is the output terminal with reference to mu balanced circuit, the REF+ pin of this output termination analog-digital conversion ic U8.Input end 3 to 9 pin, 11 pin and the equal ground connection of 12 pin of the simulating signal of U8.From the simulating signal of above-mentioned input end of analog signal 1 pin and 2 pin input by its inner Port Multiplier gating.Negative reference voltage REF-holds 13 pin and sheet choosing end 15 pin ground connection; The input voltage range of the maximum of above-mentioned input end of analog signal 1 pin and the input of 2 pin is by being added on the voltage difference decision of REF+ end with the REF-end.Power supply VCC holds 20 pin to connect+the 5V direct supply, and GND holds 10 pin ground connection; The EOC that is used to export modulus (A/D) EOC signal holds 19 pin to connect 1 pin of single-chip microcomputer U10; Clock control input end 18 pin connect 2 pin of single-chip microcomputer U10.17 pin of analog-digital conversion ic U8 are 4 bit serial address date input ends, the simulating signal input channel that is used to select analog-digital conversion ic U8 from the address date of this port input, 17 pin of analog-digital conversion ic U8 connect 3 pin of single-chip microcomputer U10,16 pin of analog-digital conversion ic U8 are 4 bit serial data output ends, and 16 pin of analog-digital conversion ic U8 connect 4 pin of single-chip microcomputer U10.At the clock negative edge of CLOCK end, the EOC end is when high level becomes low level, and analog-digital conversion ic U8 begins analog to digital conversion, and remains to that analog to digital conversion is finished and data are prepared to begin till the transmission; EOC end is when low level becomes high level, and data transmission begins; Behind the DTD, the EOC end becomes low level from high level, prepares the beginning analog to digital conversion.

21 pin of single-chip microcomputer U10 are alarm signal output ends, and this signal output part is in use under the situation that the sulfur hexafluoride gas concentration value exceeds standard or humidity value exceeds standard or the oxygen content value is not up to standard, exportable fan starting control signal and/or alarm control signal.

Light emitting diode D1 among Fig. 7 is a power light.

Still see Fig. 7, the transmitter of present embodiment also has RS-485 serial port circuit 24, and RS-485 serial ports 24 is that RS-485 serial communication interface chip U7, resistance R 36 and the RS-485 joint J4 of MAX485DS forms by model.The two ends of resistance R 36 are connected on 6 pin and 7 pin of chip U7 respectively, and the two ends of resistance R 36 connect the input end of RS-485 joint J4 respectively simultaneously.The serial data and the control end of the serial data of single-chip microcomputer U10 and control termination RS-485 serial ports 24.The serial data of single-chip microcomputer U10 and control end are 10 pin, 11 pin, 24 pin and 28 pin, and the serial data of RS-485 serial ports 24 and control end are 1 pin, 4 pin, 3 pin and 2 pin of chip U7.

RS-485 is that the balancing twisted-pair line that utilizes that U.S. electric industrial combination meeting (EIA) is formulated is made the multi-point communication standard of transmission line.It adopts differential signal to transmit; Maximum transmission distance can reach 1.2km; Maximum can connect 32 drivers and transceiver; The receiver minimum sensitivity can reach+200mV; Peak transfer rate can reach 2.5Mb/s.This shows the standard that the RS-485 agreement is formulated at remote, high sensitivity, multi-point communication just.The MAX485DS interface chip is a kind of RS-485 chip of Maxim company.This chip adopts single power supply+5V work, and rated current is 300 μ A, and adopts the half duplex communication mode.This chip has the function that the Transistor-Transistor Logic level of the serial data of the RXD end of single-chip microcomputer U10 and the output of TXD end is converted to the required level of RS-485 data serial signal.The level that the logical one of Transistor-Transistor Logic level and logical zero are corresponding respectively is 2.4V and 0.4V.The MAX485DS chip internal contains a driver and receiver.RO end and DI end are respectively the output of receiver and the input end of driver, and only needing when being connected with single-chip microcomputer U10 links to each other with the TXD end with the RXD end of single-chip microcomputer U10 respectively gets final product; Be respectively the reception of RS-485 serial communication interface chip U7 and the Enable Pin of transmission with RE end and the DE end that the P27 end of single-chip microcomputer U10 links to each other with the P23 end respectively, owing to adopt the half duplex communication mode, so when the RE end was held to logical zero for logical one, DE, this device was in accepting state; When the RE end was held to logical one for logical zero, DE, this device was in transmit status; Its side a and b is respectively the differential signal end that receives data and send data, and when the level of A end was higher than the B end, the data that representative sends were 1; When the level of A end was lower than the B end, the data that representative sends were 0.During data transmission, data layout is followed successively by: 1 start bit, 8 bit data positions, 1 position of rest.No parity position wherein, garble are detected by adding up and the method for verification realizes.Resistance R 36 between side a and b is a build-out resistor, the resistance of general optional 100 Ω.

(embodiment 2, transmitter are measured the method for sulfur hexafluoride gas concentration)

See Fig. 1, Fig. 2, Fig. 7 and Fig. 8, the transmitter that present embodiment adopted is obtained by embodiment 1, and corresponding program is set in the single-chip microcomputer of variator, during this variator work, the method of measuring sulfur hexafluoride gas concentration has following steps: when 1. transmitter is started shooting the back operate as normal, the crystal oscillating circuit 22-8 of ultrasonic detection device 22 transports to frequency divider 22-7 with the crystal oscillator signal, and temperature collection circuit 23-1 then is delivered to single-chip microcomputer 21 with the signal of the relevant environmental gas temperature value gathered after analog to digital converter 23-4 carries out analog to digital conversion, and be stored in the relevant register by single-chip microcomputer 21; The humidity Acquisition Circuit 23-3 of environmental parameter Acquisition Circuit 23 is delivered to the humidity information that collects the moisture signal input end of single-chip microcomputer 21 with the form of frequency signal, single-chip microcomputer 21 carries out drawing humidity value after the frequency computation part to it, afterwards single-chip microcomputer 21 with the data storage of above-mentioned humidity value in single-chip microcomputer 21 in the relevant register; Meanwhile, oxygen level Acquisition Circuit 23-2 is delivered to the first environment parameter signal input end of single-chip microcomputer 21 with the simulating signal of the oxygen content value in the relevant environment of gathering after analog to digital converter 23-4 carries out analog to digital conversion, single-chip microcomputer 21 with above-mentioned data storage in single-chip microcomputer 21 in the relevant register.Single-chip microcomputer 21 is also judged above-mentioned environmental gas humidity value and oxygen content value, if humidity value exceeds standard or the oxygen content value is not up to standard, then single-chip microcomputer 21 is exported control signal and/or alerting signals.

2. after frequency divider 22-7 carried out frequency division to the crystal oscillator signal of importing, the electric signal of output first frequency was exported the electric signal of second frequency simultaneously and is measured wave filter 22-6 to relatively reaching to waveform generator 22-1; After handling the electric signal of first frequency, waveform generator 22-1 produces the electric signal in the supersonic band, this electric signal amplifies and one the tunnel transports to sampling apparatus 22-3 after isolating through amplifying buffer circuit 222, comparable device 22-4 is transported on another road, and the ultrasonic transducer at the ultrasonic transducer at the transmitting terminal place of sampling apparatus 22-3 and the transmitting terminal place of comparable device 22-4 produces the ultrasound wave of same frequency simultaneously.

3. the ultrasonic transducer at the receiving end place of sampling apparatus 22-3 and comparable device 22-4 receives corresponding ultrasonic signal, and correspondingly produces a pair of electric signal; This transports to relatively to reach after shaping is amplified in isolation amplification and rectification circuit 22-5 isolation separately to electric signal and measures among the wave filter 22-6.

4. relatively reach measure the second frequency that wave filter 22-6 transports frequency divider 22-7 on the one hand electric signal as the measuring basis signal, to isolate the two paths of signals that amplification and rectification circuit 22-5 transports on the other hand and carry out the phase bit comparison, carry out the calculating of phase differential θ, carry out digital filtering again, obtain the signal of an accurate relevant hyperacoustic phase differential θ at last according to the measuring basis signal.

Wherein, relatively reach measure wave filter 22-6 by window comparator 22-6-1 simultaneously to comparing from the rising edge of the received signal of the ultrasonic transducer at the receiving end place of comparable device 22-4 with to the priority time that next rising edge or negative edge arrived from the waveform of the received signal of the ultrasonic transducer at the receiving end place of sampling apparatus 22-3, be Δ l high level signal thereby obtain a duration; Digit phase measuring appliance 22-6-2 is with the frequency signal f from the second frequency output terminal of frequency divider 22-7 ₂As the measuring basis signal described Δ l is calculated, draw the pairing phase difference θ 0≤Δ of Δ l θ＜π; When not having sulfur hexafluoride gas to leak, promptly sulfur hexafluoride gas concentration is 0%, Δ l=0 then, Δ θ=0; If sulfur hexafluoride gas has leakage, and along with the increase of the sulfur hexafluoride gas concentration that leaks, the velocity of propagation of ultrasound wave in sampling apparatus 22-3 begins to reduce but its frequency is constant, and velocity of propagation and the frequency of ultrasound wave in comparable device 22-4 is all constant; So described Δ l and Δ θ also increase gradually; If the sulfur hexafluoride gas concentration that leaks is bigger, when Δ θ=π radian, Δ l saltus step is 0, and digit phase calculates device 22-6-2 makes Δ θ by π radian saltus step to 0 radian, and the counting variable n in the program adds 1 simultaneously, and the initial value of n is 0; And Δ l and Δ θ continue to increase along with the increase of the sulfur hexafluoride gas concentration that leaks, and when Δ θ=π radian was arranged once more, Δ θ was that saltus step is 0 radian, and the cycle count variable n that calculates in the device 22-6-2 of digit phase adds 1 more simultaneously, by that analogy; Last digit phase calculates device 22-6-2 and obtains the θ value according to formula θ=π n+ Δ θ.

Relatively reach and measure ultrasonic measurement signal data and the control end that wave filter 22-6 transfers to the signal of above-mentioned phase differential θ single-chip microcomputer 21; Single-chip microcomputer 21 with the signal storage of this phase differential θ in single-chip microcomputer 21 in the relevant register, as shown in Figure 2.

5. single-chip microcomputer 21 calculates according to the signal of the above-mentioned phase differential θ in its register and the signal of above-mentioned ambient temperature value, draws the concentration value of sulfur hexafluoride gas.

6. the sulfur hexafluoride gas concentration value that goes out of 21 pairs of aforementioned calculation of single-chip microcomputer is judged, if the sulfur hexafluoride gas concentration value surpasses default exceeding standard during concentration value 1000PPM, then single-chip microcomputer 21 output control signal and/or alerting signals.

(application examples 1)

Seeing Fig. 3, should use-case be that the transmitter with embodiment 2 is used for the sulfur hexafluoride gas concentration supervisory system.Be to use the RS-485 network specifically, master controller 1, host computer 3 and each transmitter are connected and form a system that sulfur hexafluoride gas concentration is monitored in real time.

Still see Fig. 3, master controller 1 have the main control singlechip 11 that is used to receive and handle the data that each transmitter of being connected on the RS-485 network gathers, by RS-485 network and each transmitter carry out communication and data transmission RS-485 serial ports 12, be used for carrying out RS-232 serial ports 13, the keyboard circuit 14 that the user controls usefulness of communication and data transmission and the LCD LCD 15 of the data that are used to show that each transmitter is gathered with host computer 3.

See Fig. 9, label is that the main control singlechip 11 of U1 is the 89S52 of atmel corp, and this chip arithmetic speed is very fast, stable performance, and low price.X1 end, X2 end are clock signal input terminal; RXD end, TXD end are the serial data input end from RS-485 serial ports 12; INT1 end, INT2 end, T1 end and T0 end are the input end of keyboard circuit 14; Port P00, P01, P02, P03, P04, P05, P06 and P07 are data output end, and the BD0 that connects LCD LCD 15 respectively holds to BD7 and holds.

Still see Fig. 9, RS-485 serial ports 12 is that RS-485 serial communication interface chip U5, resistance R 7 and the RS-485 joint J1 of MAX485DS forms by model.

Still see Fig. 9, RS-232 serial ports 13 is that RS-232 serial communication interface chip U4, RS-232 joint and capacitor C 80, C81, C82 and the C83 of MAX232ACPE forms by signal.Wherein, host computer 3 is PCs, and this PC has RS-232 interface.

Still see Fig. 9, keyboard circuit 14 is the keyboard control chip 74HC148 of U2 by label, button S1, S2, S3, S4, S5, S6 and reset key, and pull-up resistor R1, R2, R3, R4, R5 and R6 form.Wherein, the reset key that is connected on the RESET end of main control singlechip 11 is not drawn in schematic diagram.Keyboard comprises reset key, inquiry options button, page up key, Page Down key, display switching key, printing key and these 7 buttons of software zeroing key.

Still see Fig. 9, LCD LCD 15 is that the LCD MODULE HD44780 of U3 and Sheffer stroke gate U2A, U2B and U2C that 3 models are 74ALS00 form by label.

Still see Fig. 9, the output terminal of keyboard circuit 14 is INT1 end, INT0 end, X1 end, the X2 end that EO end, C end, B end, the A end of keyboard control chip U2 meets main control singlechip U1 respectively; The input end of LCD LCD 15 is that the BD0 to BD7 of LCD MODULE U3 holds the P00 to P07 that meets main control singlechip U1 respectively to hold; The P23 end of main control singlechip U1, P24 end, RXD end, TXD end connect DE end, RE end, RO end, the DI end of the serial communication interface chip U5 in the RS-485 serial ports 12 respectively; Joint J1 in the RS-485 serial ports 12 and the joint J4 among Fig. 7 join.The RXD end of main control singlechip U1, TXD end connect T1 IN end, the R1 OUT end of the serial communication interface chip U4 in the RS-232 serial ports 13 respectively; RS-232 serial ports 13 connects the RS-232 interface that host computer 3 is a PC.

In should use-case, there be 32 with the number of the master controller 1 two-way transmitter that is electrically connected 2.

After main control singlechip 11 received the data that transmitter sends over by 485 networks, the user can show in LCD LCDs 15 by the data of keyboard circuit 14 with the gas concentration of certain transmitters sense.

See Fig. 4 and Fig. 5, the method that is adopted when carrying out communication between the master controller of above-mentioned sulfur hexafluoride gas concentration supervisory system based on the RS-485 network and the transmitter has following steps:

When 1. the slave of master controller 1 calling party's appointment is transmitter, master controller 1 send the serial interrupting information to all be connected in transmitter on the RS-485 network, this interrupting information comprises the address information of this transmitter, then the answer signal of the single-chip microcomputer 21 of the transmitter of master controller wait user appointment.

2. all transmitters that are connected on the RS-485 network carry out the collection of sulfur hexafluoride gas concentration data, the collection of humidity value in the environment and the collection of oxygen content value to the control point, place; Simultaneously the RS-485 serial ports 24 of transmitter is in the state that receives the external interrupt information that master controller 1 sends.

3. after all single-chip microcomputers 21 that are connected in the transmitter on the RS-485 network received this look-at-me, the master routine that stops to carry out then carry out this interruption promptly interrupted inlet; Carry out to close serial again and interrupt, promptly no longer carry out other lower priority or the external interrupt of All factors being equal, preference will be give to level; Afterwards, the single-chip microcomputer 21 of each transmitter begins to judge whether the address information that is comprised in the above-mentioned look-at-me conforms to this machine address, if do not conform to, then the single-chip microcomputer 21 of this transmitter is carried out the capable interruption of open string, even the RS-485 serial ports 24 of transmitter is in the state that receives the external interrupt information that master controller 1 sends again, and the arithmetical unit of the single-chip microcomputer 21 of transmitter is got back to the place continuation execution of performed master routine before above-mentioned interruption, promptly interrupts outlet; If conform to, then the single-chip microcomputer 21 of this transmitter sends answer signal through RS-485 serial ports 24 to master controller 1, and the single-chip microcomputer 21 of this transmitter enters the state of waiting for the monitor command that receives master controller 1 afterwards.

4. if master controller 1 is confiscated answer signal or the answer signal received is incorrect, then master controller 1 send once more same serial interrupting information to all be connected in transmitter on the network line of RS-485 serial ports; Same transmitter is finished twice calling and all no response signal or answer signal are all incorrect in setting-up time, and then master controller 1 prompting error message enters the state of waiting for that the user handles; If it is correct that master controller 1 is received from answer signal and this answer signal of the single-chip microcomputer 21 of the transmitter of appointment, then this master controller 1 begins to send the single-chip microcomputer 21 of monitor command to this transmitter.

5. after the single-chip microcomputer 21 of this transmitter receives above-mentioned monitor command, begin to judge whether this order is control word, if not then the single-chip microcomputer 21 of transmitter is carried out the capable interruption of open string, jumps out interrupt routine afterwards; If, then single-chip microcomputer 21 beginnings of this transmitter are carried out control commands corresponding according to this control word, and press the RS-485 serial communication protocol sends the concentration value of its measured sulfur hexafluoride gas to master controller 1 through RS-485 serial ports 24 data, the data of environmental gas humidity value and the data of oxygen content value; Single-chip microcomputer 21 is carried out the capable interruption of open string afterwards, jumps out interrupt routine at last.

6. main control singlechip 11 corresponding data that each transmitter transported that will receive carries out geocoding and deposits relevant position in its register in.

7. the state of main control singlechip 11 timing scan keyboard circuits 14, if the button closure is arranged, the then control of main control singlechip 11 response keyboard circuits 14; The user is presented on the LCD LCDs 15 one by one by concentration value, environmental gas humidity value or the oxygen content value of the sulfur hexafluoride gas that Keyboard Control can record above-mentioned each variator.

See Fig. 6, the method that is adopted when carrying out communication between the master controller of above-mentioned sulfur hexafluoride gas concentration supervisory system based on the RS-485 network and the host computer has following steps:

1. after main control singlechip 11 is finished single-chip microcomputer hand shake procedure with variator, will from 12 inputs of RS-485 serial ports, be connected the SF that each transmitter on the RS-485 network of master controller place records ₆The data of the data of the data of the concentration value of gas, environmental gas humidity value and oxygen content value are carried out geocoding and are deposited relevant position in its register in.

2. the state of main control singlechip 11 timing scan keyboard circuits 14, if the button closure is arranged, the then control of main control singlechip 11 response keyboard circuits 14; The SF that the user can record above-mentioned each variator by Keyboard Control ₆The concentration value of gas, environmental gas humidity value or oxygen content value are presented on the LCD LCDs 15 one by one.

3. after main control singlechip 11 is finished hand shake procedure with host computer 3, the SF that main control singlechip 11 records above-mentioned each transmitter through RS-232 serial ports 13 by the RS-232 serial communication protocol ₆The data transmission of the data of the data of the concentration value of gas, environmental gas humidity value and oxygen level value is to the respective input of host computer 3.

4. host computer receives the data in the autonomous controller and it is carried out real-time analysis by the RS-232 serial ports, preserves the data that each transmitter records according to the address code information of each transmitter, and host computer is stored, managed alarm log simultaneously.

5. respond customer requirements, show the data that each transmitter records in real time,, in time take appropriate measures if find that certain variator goes wrong or fault in the mode of chart or figure.

6. host computer is stored, is managed the historical data of each transmitter, and the user also can carry out system's setting to this software simultaneously; When finding that somewhere gas to be measured when exceeding standard, can manually start corresponding blower fan or start corresponding warning device.

In other embodiment of transmitter of the present utility model, comparable device 224 also can adopt the form of closed structure, at this moment, only need place it near the of sampling apparatus 22-3 gets final product, sampling apparatus 223 then must adopt the version that communicates with outside air, concrete which kind of structure that adopts will see that also this sampling apparatus 22-3 is arranged on the relative position of the equipment of being monitored that contains sulfur hexafluoride accordingly and decides.If comparable device 224 also adopts the version that communicates with outside air, then preferably has identical version, and be arranged on the top of sampling apparatus 22-3 with sampling apparatus 22-3.

Claims (6)

1, a kind of transmitter of measuring sulfur hexafluoride gas concentration has ultrasonic detection device (22), and ultrasonic detection device (22) has sampling apparatus (22-3) and comparable device (22-4); The inner end as transmitting terminal of sampling apparatus (22-3) and comparable device (22-4) is equipped with the hyperacoustic ultrasonic transducer of emission, is equipped with as the other end of receiving end and receives hyperacoustic ultrasonic transducer; It is characterized in that: also have single-chip microcomputer (21) and environmental parameter Acquisition Circuit (23); Ultrasonic detection device (22) also has waveform generator (22-1), amplifies buffer circuit (22-2), isolates amplification and rectification circuit (22-5), relatively reaches and measure wave filter (226), frequency divider (227) and crystal oscillating circuit (22-8); Sampling apparatus (22-3) communicates with outside air; The crystal oscillator signal output part of crystal oscillating circuit (22-8) connects the crystal oscillator signal input part of frequency divider (22-7); Frequency divider (22-7) has two output terminals, exportable first frequency f when being to use respectively ₁First frequency output terminal and exportable second frequency f when using ₂The second frequency output terminal, described first frequency f ₁In the frequency of ultrasonic scope, described second frequency f ₂Be first frequency f ₁50 to 300 times; The input end of the first frequency output terminal welding wave generator (22-1) of frequency divider (22-7), its second frequency output termination relatively reaches the frequency signal input end of measuring wave filter (22-6); The output termination of waveform generator (22-1) is amplified the input end of buffer circuit (22-2), the output terminal while of amplifying buffer circuit (22-2) is electrically connected with the power end of the ultrasonic transducer at the transmitting terminal place of sampling apparatus (22-3) and comparable device (22-4), and the output terminal of the ultrasonic transducer at the receiving end place of sampling apparatus (22-3) and comparable device (22-4) is electrically connected with the input end of corresponding isolation amplification and rectification circuit (22-5) separately; Each output terminal of isolating amplification and rectification circuit (22-5) is electrically connected with the respective input that relatively reaches 2 ultrasonic measurement signals measuring wave filter (22-6), relatively reaches the ultrasonic measurement signal data of the ultrasonic measurement signal data of measurement wave filter (22-6) and control end and single-chip microcomputer (21) and control end is two-way is electrically connected; Environmental parameter Acquisition Circuit (23) has temperature collection circuit (23-1); The temperature signal input end electricity of the temperature signal output terminal of temperature collection circuit (23-1) and analog to digital conversion circuit (23-4) links to each other, the first environment supplemental characteristic of the data of analog to digital conversion circuit (23-4) and control end and single-chip microcomputer (21) and control end is two-way is electrically connected; Single-chip microcomputer (21) is variable and can calculate sulfur hexafluoride gas concentration according to corresponding program formula with ultrasonic measurement signal and temperature signal in use.

2, the transmitter of measurement sulfur hexafluoride gas concentration according to claim 1 is characterized in that: the hyperacoustic transducer of emission of sampling apparatus (22-3) and the distance that receives between hyperacoustic transducer are equal to the hyperacoustic transducer of emission of comparable device (22-4) and the distance between the hyperacoustic transducer of reception; Comparable device (22-4) and sampling apparatus (22-3) all are that a shell is tubular and by being arranged on the device that 2 on the tubular shell communicates with extraneous air to 6 holes; The hyperacoustic ultrasonic transducer of emission of comparable device (22-4) and sampling apparatus (22-3) is separately positioned on an end of corresponding tubular shell inside, and the hyperacoustic ultrasonic transducer of reception of comparable device (22-4) and sampling apparatus (22-3) is separately positioned on the other end of corresponding tubular shell inside.

3, the transmitter of measurement sulfur hexafluoride gas concentration according to claim 2 is characterized in that: comparable device (22-4) is 2 to 5 meters directly over sampling apparatus (22-3).

4, the transmitter of measurement sulfur hexafluoride gas concentration according to claim 1, it is characterized in that: environmental parameter Acquisition Circuit (23) also has oxygen level Acquisition Circuit (23-2) and humidity Acquisition Circuit (23-3), the oxygen content signal output terminal of oxygen level Acquisition Circuit (23-2) links to each other with the oxygen content signal input end of D/A converting circuit (23-4), and the moisture signal output terminal of humidity Acquisition Circuit (23-3) links to each other with the moisture signal input end of single-chip microcomputer (21); Single-chip microcomputer (21) also has control signal output ends, when this control signal output ends is to use under the situation that the sulfur hexafluoride gas concentration value exceeds standard or humidity value exceeds standard or the oxygen content value is not up to standard, the port of exportable fan starting control signal and/or alarm control signal; This transmitter also has RS-485 serial port circuit (24), the serial data of the serial data of single-chip microcomputer (21) and control end and RS-485 serial port circuit (24) and control end is two-way is electrically connected.

5, the transmitter of measurement sulfur hexafluoride gas concentration according to claim 1 is characterized in that: relatively reach measurement wave filter (22-6) and have window comparator (22-6-1), digit phase calculating device (22-6-2) and digital filter (22-6-3); 2 input ends of window comparator (22-6-1) are and relatively reach 2 ultrasonic measurement signal input parts measuring wave filter (22-6), the output termination digital phasemeter of window comparator (22-6-1) is calculated the ultrasonic measurement signal input part of device (22-6-2), digit phase calculates the input end of the output termination digital filter (22-6-3) of device (22-6-2), and the ultrasonic measurement signal data of digital filter (22-6-3) and control end are and relatively reach ultrasonic measurement signal data and the control end of measuring wave filter (22-6).

6, the transmitter of measurement sulfur hexafluoride gas concentration according to claim 1 is characterized in that: frequency divider (22-7), waveform generator (22-1) and relatively reach and measure wave filter (22-6) and be arranged in the complex programmable logic device (CPLD) (22-10).

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