Chinese name: Acoustic instrument uses: concrete crack depth detection and other components: transmitting system and receiving system functions: signal amplification, signal filtering, brief introduction of acoustic instrument, acoustic instrument uses, acoustic instrument development, acoustic instrument composition, acoustic instrument functions, acoustic instrument characteristics, acoustic instrument technology, and acoustic instrument introduction are mainly composed of transmitting system (transmitter, transmitting transducer), receiving system (receiver, receiving transducer) and microcomputer (application). Among them, the working process of the transmitter is: the sound source signal generator (the main component is the oscillator) generates electric pulses with a certain frequency, which are amplified by the transmitting transducer and converted into sound waves, which are radiated to the rock mass. Electro-acoustic transducer (including transmitting transducer and receiving transducer) is an instrument to realize the mutual conversion of sound and electric energy. The receiver amplifies the received electric pulse and displays the acoustic waveform on the screen. By adjusting the vernier potentiometer, the arrival time can be displayed on the digital display. If the receiver is connected to a microcomputer, it can process acoustic signals. Application of acoustic instrument 1. Ultrasonic transmission method to detect the integrity of foundation piles II. Detection of concrete crack depth. Ultrasonic rebound comprehensive method to detect concrete strength 4. P-wave velocity test of geological exploration rock mass 5. Detection of loose zone in tunnel rock mass. Development simulator of acoustic instrument for testing dynamic mechanical parameters of nonmetallic materials: the first generation of electronic tube acoustic instruments appeared in the 1950s. At 1964, Tongji University developed the first acoustic instrument in China. At the end of 1970s, some domestic units developed a number of representative sonic instruments with transistor separation elements: CTS-25 and SYC-2 digital machines; the second generation was 1990. Tianjin Building Instrument Factory first successfully developed the first digital acoustic instrument in China. Due to the limitation of digital acquisition and transmission speed, this acoustic instrument can't dynamically display waveforms in real time. In 1990s, the RSM-SY5 acoustic instrument produced by Wuhan Institute of Geotechnical Mechanics, Chinese Academy of Sciences came out. Ultrasonic automatic pile measuring instrument for foundation piles: On the basis of digital ultrasonic instrument, the third generation added automatic depth recording function to improve the working efficiency and detection accuracy of foundation pile transmission method. Representative instruments: BL-520A, RS-ST0 1(D), RSM-SY6 pile multi-span ultrasonic automatic tracker: the fourth generation has realized multi-channel spontaneous self-mining design, which can complete four pipes and six sections of detection at the same time, the detection efficiency is improved by 6 times, and the field detection intensity is greatly reduced. Representative instruments: RSM-SY7(T), RSM-SY7(F), RS-ST06(D), YL-PST(E) Acoustic instrument composition ◆ Computer part (control, storage and display) ◆ High-voltage transmission and control part ◆ Program-controlled amplification and attenuation part ◆A/D conversion and acquisition part Acoustic instrument function ◆ Signal amplification (? Low-pass) ◆ Display waveform (time delay, recording length) ◆ Read parameters (sound time, sound amplitude) ◆ Features of sonic instrument ◆ Automatically adopt appropriate magnification ◆ Automatically interpret parameters (sound time, sound amplitude, frequency, etc. ) ◆ Flexible and efficient display and recording mode ◆ Real-time and fast on-site analysis function ◆ Convenient data management (original data and results) ◆ Both universality and specificity ◆ Friendly interface RSM-SY7 technical features: 1. The host computer is wirelessly controlled, and the wireless control distance can reach 100㎡. Small size, light weight, easy to carry and operate. 3. It is the world's first four-channel spontaneous self-collection full-combination ultrasonic detection of pile profile, and has applied for many invention patents. 4. Self-collecting circuit design, without changing the position of the probe relative to the sound tube, completes six full-combination tests at one time, which greatly improves the detection speed and greatly reduces the work intensity of on-site inspectors. 5. Four independently controllable transmitting and receiving channels, multi-pipe foundation pile acoustic transmission detection efficiency is higher. 6. For each profile test waveform, the gain delay can be controlled and adjusted. 7. The distance between measuring points can be adjusted from 5 cm to 50 cm, and repeated tests are not needed. 8. The automatic counting lifting device is convenient and quick to connect, and the maximum lifting speed can reach 60 m/mim. 9. The instrument is made of metal shell and has a solid structure. Durable sound wave detector technology JJG 990-2004 Verification regulation of traffic regulations for sound wave detectors (JTG/ T F8 1-0 1 2004) Technical requirements for sound wave instruments ◆ The detector should have the function of transmitting one signal and receiving two signals ◆ High-voltage step or rectangular pulse should be adopted for sound wave transmission ◆ The frequency band of the receiving amplifier should be 5-200kHz ◆ The gain should not be less than/ Kloc-0/00dB, amplitude measurement range of 80dB ◆ Timing display range is more than 2000μs, Accuracy is better than 0.5μs ◆ The analog-to-digital conversion accuracy of the collector is not less than 8bit ◆ The acquisition frequency is not less than 10MHz ◆ The maximum acquisition length is not less than 32k 《 Technical Requirements for Acoustic Instruments in Railway Code (TB 102 18-2008) 》◆ It has the following functions: 00μs, and the accuracy is greater than or equal to 0.5μs ◆ The voltage amplitude is not less than 500V ◆ The system frequency band is 5-200kHz ◆ The sound amplitude measurement range is not less than 80dB, and the relative error of sound amplitude measurement is less than 5% ◆ The maximum dynamic range of the system is not less than 100dB ◆ The analog-to-digital conversion accuracy of the collector should not be less than 1μs, Adopt the technical requirements of the building code (JJ106 2003) for acoustic instruments with the length not less than 1024 ◆ Acoustic emission voltage: 200- 1000V ◆ The frequency band of the receiving amplifier is 1-200kHz ◆ The dynamic range of the receiving amplifier is not less than/KLOC-. The technical requirements of the acoustic instrument specification (JJ1062012) are that it has the functions of real-time display and recording of the time history curve of the received signal and frequency measurement or spectrum analysis. The minimum sampling time interval is less than or equal to 0.5μs, the relative error of sound amplitude measurement is less than 5%, and the frequency width of the system is 5~200kHz. The maximum dynamic range of the system is not less than 100dB ◆ The acoustic emission pulse is a step or rectangular pulse, and the voltage amplitude is 200~ 1000V ◆ It has the function of real-time display of the first wave ◆ It has the function of automatically recording the acoustic emission and receiving the position of the transducer.