روش اندازه گیری صحیح کنتور نویز
در هنگام اندازه گیری کنتور نویز، ابزار باید دنده درست را با توجه به وضعیت انتخاب کند، دو طرف کنتور نویز را با هر دو دست صاف نگه دارد و میکروفن به منبع صوتی اشاره می کند تا اندازه گیری شود. از کابل های پسوند و میله های پسوند نیز می توان برای کاهش تأثیر ظاهر کنتور نویز و بدن انسان بر اندازه گیری استفاده کرد. . موقعیت میکروفن باید بر اساس مقررات مربوطه تعیین شود.
متر سطح صدا که توسط دستگاه نویز برای اندازه گیری نویز استفاده می شود را می توان با توجه به حساسیت پاسخ سر متر به چهار نوع تقسیم کرد:
(1) "آهسته". ثابت زمانی سر متر ۱۰ متر است که عموماً برای اندازه گیری نویز حالت ثابت استفاده می شود و مقدار اندازه گیری شده یک مقدار مؤثر است.
(2) "Fast". ثابت زمانی سر متر ۱۲۵ متر است که عموماً برای اندازه گیری نویز ناپایدار و نویز ترافیک با نوسانات بزرگ استفاده می شود. دنده سریع نزدیک به پاسخ گوش انسان به صدا است.
(3) "پالس یا پالس نگه دارید". زمان افزایش سوزن ساعت ۳۵ متر است که برای اندازه گیری نویز پالس با مدت زمان طولانی مانند پانچ پرس، چکش و غیره استفاده می شود. مقدار اندازه گیری شده حداکثر مقدار مؤثر است.
(4) "Peak hold". The rise time of the watch hand is less than 20ms. It is used to measure short-duration pulse sounds, such as guns, cannons and explosions, and the measured value is the peak value. That is the maximum value. Distance Meter Altimeter Laser Line Projector Flowmeter GPS Thickness Gauge Leveler Flat Panel Waveform Recorder Test Fixture Voltage and Current Recorder Data Collector Graphic Recorder Flow Totalizer
متر سطح صدا را می توان با فیلتر خارجی و ضبط کننده متصل به انجام تجزیه و تحلیل طیف بر روی نویز. متر سطح صدای دقیق داخلی ND2 مجهز به فیلتر صفحه اکتاو است که حمل آن به صحنه و انجام تجزیه و تحلیل طیف آسان است. کالیبراتور کالیبراتور دما کالیبراتور فشار کالیبراتور نویز متر نویز کالیبراتور جریان کالیبراتور چند منظوره کالیبراتور رطوبت کالیبراتور ph کالیبراتور PH
Improve the structure of mechanical equipment and apply new materials to reduce noise. With the development of material science and technology, various new materials emerge as the times require, and it has become a reality to use some alloys with high internal friction, high damping, and high-strength plastics to produce machine parts. For example, high-strength plastic parts are often used in automobile production. For fans, different forms of blades produce different noises. Choosing the best blade shape can reduce noise. For example, changing the fan blade from a straight blade to a curved shape, or reducing the length of the blade can reduce noise. The noise generated by the general gear transmission is relatively large, up to 90dB. If helical gears or helical gears are used instead, the coincidence coefficient during meshing is large, and the noise can be reduced by 3 to 16dB. If the belt drive is used to replace the general gear rotation, the noise can be reduced by about 15dB because the belt can reduce vibration and damping. For gear-type transmissions, noise can also be reduced by reducing the linear velocity of the gears and selecting an appropriate transmission ratio. Experiments have shown that if the linear speed of the gear is reduced by half, the noise will be reduced by about 6dB.
Improve the machining accuracy and assembly quality of parts. The improvement of the processing precision of the parts reduces the friction between the parts as much as possible, thereby reducing the noise. Improving the quality of assembly, reducing eccentric vibration, and increasing the rigidity of the casing can all reduce the noise of machinery and equipment. For bearings, if the machining accuracy of the rollers is increased by one level, the noise of the bearings can be reduced by 10dB. Noise control based on mechanical principles mainly depends on the research and development, production and assembly of automobiles, and is generally a noise reduction measure taken before the vehicle leaves the factory. In the later use and maintenance process, avoiding no-load and overloading of mechanical equipment and vehicles, and choosing good lubricating grease can reduce noise.
Noise control measures based on the principle of acoustics: In addition to the above methods of reducing noise, acoustic control methods can also be used to reduce noise, mainly including sound absorption, sound insulation, shock absorption, sealing, etc. For automotive noise control, since the noise-causing components such as the engine, exhaust pipe, and tires are finalized when the vehicle leaves the factory, the design level and assembly process of each component determine the size of the noise, and also reflect a The technical level and technological content of the car. Tranquil car sound insulation is mainly researched and developed from the control of the barrier transmission path.
