Sounds surround us everywhere - only in rare cases can a modern person completely immerse himself in silence. In this regard, the importance of regulation of noise parameters increases. In the workplace, for example, there are special requirements for the organization of working conditions. The list of such requirements certainly includes optimal indicators of sound exposure. However, a noise study may also be required in other situations - in a medical facility, in public places and, of course, in the home. For this purpose, special devices are used - sound level meters. But first, it’s worth understanding the very nature of sound.
Sound sources
Most of the urban noise sources are generated by anthropogenic sound generators. For example, vehicles, air flows that pass between buildings, engineering systems, etc. As a rule, the causes of this kind of noise are negative, since they are dominated by low frequencies, as well as a chaotic change of accents throughout the spectrum. This can be judged especially by the work of industrial enterprises and communication equipment.
Of course, the most favorable, from the point of view of acoustics, the situation is noted outside the city. In thisIn this case, nature itself is the source. One of the most soothing and relaxing is the sound of the sea, which is characterized by periodic and pronounced fluctuations. The unhurried and monotonous sound creates a unique and attractive marine rhythm that helps strengthen the nervous system.
Device arrangement
In today's sound level meter market, digital instruments are popular today. They are small in size and have a reliable plastic case, which is complemented by a microphone - however, this element can be integrated into the device. The device also includes an amplifier, filtering elements, an indicator and a detector. Actually, the human ear has many parts that are similar in functionality. In turn, a special technique allows you to perform a noise study with the fixation of several parameters at the same time. Filters capture sounds with different frequencies, and information about the measurements taken is reflected on the screens in decibels. As far as power is concerned, most sound level meters are powered by a battery that can last from 50 to 70 hours.
Working principle
As for the principle of operation, in this case it is more appropriate to compare the device with a microphone. The main difference will be that the sound level meter interacts during the measurement process with a voltmeter calibrated in decibels. Since the electrical flow signal at the output of the microphone is equivalent to the original noise, the addition in the level of acoustic pressure that acts on the membrane will causea similar increase in voltage when entering the voltmeter. This is the principle on which the measurement of noise is based, the indicators of which are reflected on the display. To perform measurements of sound pressure indicators, the signal is passed through special filters - this is done at the moment when it is on the way from the microphone to the voltmeter.
Since the ability of the ear to perceive sound is determined not only by the frequency properties of noise, but also by its intensity, the devices provide several types of filtering elements. The choice of a specific device depends on the characteristics of the permissible noise in the measurement area. Filters make it possible to simulate the amplitude-frequency spectrum under conditions of a given noise power.
Specifications
Manufacturers strive to distinguish between models designed exclusively for measuring loudness and devices for universal measurements. Nevertheless, the volume level remains one of the key characteristics of almost all sound level meters - this figure varies from 30 to 130 dB. It is important to note one feature of noise meters. Some models, when operating in conditions where the sound factor exceeds the maximum scale bar, do not perform a noise study at all due to the limitations of their capabilities. The next characteristic is the measurement accuracy. This quality is determined by the error, which can be from 1 to 1.5 dB. Accordingly, the smaller the deviation in the measurements of the sound level meter, the higher its accuracy. To work appliancestemperature may be influenced. For example, if the range is from 0 to 40 °С, then the device can be used in open areas.
Producers
On the market, you can find devices from specialized manufacturers of measuring equipment, as well as products from well-known construction brands. The first category should include Testo models, which can be called the best in the class. They are distinguished by a wide frequency range, capacious batteries and a wide range of decibel measurements. However, devices of this brand are the most expensive - an average of 20 to 30 thousand rubles. If you plan to study noise in a domestic environment, then you can pay attention to the products of Geo-Fennel and ADA. Firstly, the models of these manufacturers provide good measurement accuracy, and secondly, they are affordable - on average, such devices cost 3-4 thousand rubles.
Reviews on sound level meters
Users note the ease of use of digital sound level meters. Most manufacturers offer devices with ergonomic cases, as well as informative screens, which adds comfort in the process. The disadvantages of many devices of this type, the owners include a short time of operation of the charger and serious errors. However, the last nuance largely depends on which noise sources are being studied. In addition to the direct function, it is also recommended to pay attention to the device's ability to operate in harsh environmental conditions. The presence of mechanical resistance andhull moisture is clearly regarded as an advantage.
Conclusion
Even with the use of modern technologies, developers of measuring equipment can not solve all the problems related to the determination of sound indicators. True, for most users, the existing offers are enough. For example, the sound of the sea provides frequency fluctuations on average from 31 to 20,000 Hz. To cover this spectrum today, it will not be difficult to find a device from the middle segment. Another thing is that highly specialized professional tasks may require equipment not only with extended ranges of basic operating parameters, but also with the ability to perform additional measurement functions.
