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The noise of biomedical devices for domiciliary use on the example of a nebulizer

Jakubek B., Rukat W., Grochalski K.

Vibrations in Physical Systems

2018

Vol. 29

art. no. 2018017

Widely available and inexpensive biomedical devices for domiciliary use may emit noise. Nebulizers are one of them. They allow taking drugs in the form of vapours thanks to vaporization under reduced pressure using an ejector (vacuum generator). The sources of noise in a nebulizer are an air compressor and a vaporizing tip. The presence of two sources with a different noise character and unfixed spatial orientation allows to classify a nebulizer as a device with extensive sound sources (DESS). The article presents the results of acoustic measurements of the nebulizer and its components. Differences in the nature of components’ noise were found and their estimates were compared. Noise hazards for the device’s user were determined and the premises for the noise parameterization of devices of this type were specified.

The noise emitted by a vacuum cleaner treated as a device with extensive sound sources

Rukat W., Jakubek B., Madej A.

Vibrations in Physical Systems

2018

Vol. 29

art. no. 2018015

Vacuum cleaners can be found in almost every household. They are one of the most intense noise sources there. Noise generated by vacuum cleaners is partially of mechanical, electrical and aerodynamic origin. A suction unit is the source of mechanical and electromagnetic noise. A suction nozzle or a cleaning head as well as a flexible hose that connects the components are sources of aerodynamic noise. The noise of the suction unit depends on the load and the technical condition of the motor. The noise of the nozzle and the hose depend on the flow capacity, presence of solid particles and the type of cleaned surface. The article presents a comparison of acoustic parameters of a vacuum cleaner working on various surfaces. In addition, the noise generated by the vacuum cleaner was compared according to the standard noise testing procedure and according to the definition of devices with extensive sound sources.

Determination of acoustic parameters of devices with extensive sound sources

Jakubek B., Barczewski R.

Vibrations in Physical Systems

2016

Vol. 27

129--134

In most cases, while the sound power level of machines and devices is determined, it is assumed that tested objects are sound sources which can fit in a so-called reference box. Such an approach takes into account the influence of local sources. Although it does not allow their localization, separate noise measurement and evaluation. There are devices which have two or more relevant sound sources. In this paper this type of devices has been defined as devices with extensive sound sources (DESS). The tested device is a functional unit but its local sound sources are distant from each other. The results showed that determining the sound power level only is not sufficient for proper parameterization of noise emitted by DESS.