scholarly journals THICKNESS INFLUENCE ON ABSORBING PROPERTIES OF STRATIFIED COMPOSITE MATERIALS

2016 ◽  
Vol 21 (4) ◽  
Author(s):  
IAȘNICU (STAMATE) IULIANA ◽  
VASILE OVIDIU ◽  
IATAN RADU
Keyword(s):  
Composite Material ◽  
Sound Pressure ◽  
Layered Composite ◽  
Sound Level ◽  
Pressure Level ◽  
Sound Level Meter ◽  
Absorbing Materials ◽  
Absorbing Material ◽  
Study Case ◽  
Level Meter

Plates known as sound absorbing materials: textiles recovered fabrics plus polyethylene are made layered composite material intended to be used to encapsulate industrial engines, as sources of noise in the production departments. Influence of thickness sound-absorbing material can be supported by the values obtained for the absorption coefficient, but it can be studied as a study case in the anechoic chamber, where the sound pressure level is measured with a sound level meter. Cases captured: a free engine; the engine placed in a metallic cube and motor inserted; metal cube that was doubled separately with one material and then with the composite material proposed. For each situation are eight determinations on the perimeter of a circle with a radius of one meter from the source of the noise. Plot a graph of experimental results that support the idea: greater thickness of the layer of material will cause a better absorption of noise.

scholarly journals THICKNESS INFLUENCE ON ABSORBING PROPERTIES OF STRATIFIED COMPOSITE MATERIALS

2015 ◽  
Vol 21 (4) ◽  
pp. 28-34
Author(s):  
IULIANA IAȘNICU (STAMATE) ◽  
OVIDIU VASILE ◽  
RADU IATAN
Keyword(s):  
Composite Material ◽  
Sound Pressure ◽  
Layered Composite ◽  
Sound Level ◽  
Pressure Level ◽  
Sound Level Meter ◽  
Absorbing Materials ◽  
Absorbing Material ◽  
Study Case ◽  
Level Meter

Plates known as sound absorbing materials: textiles recovered fabrics plus polyethylene are made layered composite material intended to be used to encapsulate industrial engines, as sources of noise in the production departments. Influence of thickness sound-absorbing material can be supported by the values obtained for the absorption coefficient, but it can be studied as a study case in the anechoic chamber, where the sound pressure level is measured with a sound level meter. Cases captured: a free engine; the engine placed in a metallic cube and motor inserted; metal cube that was doubled separately with one material and then with the composite material proposed. For each situation are eight determinations on the perimeter of a circle with a radius of one meter from the source of the noise. Plot a graph of experimental results that support the idea: greater thickness of the layer of material will cause a better absorption of noise.

Research on the Vibration Measurement Approach to the On-Line Noise Evaluation for Vehicle Transmissions

2012 ◽  
Vol 562-564 ◽  
pp. 1163-1167
Author(s):  
Feng Qiang Zhao ◽  
Guang Qiang Li ◽  
Hong Ying Hu ◽  
Jia Lu Du ◽  
Chen Guo
Keyword(s):  
Sound Pressure Level ◽  
Production Line ◽  
Background Noise ◽  
Sound Pressure ◽  
Sound Level ◽  
Pressure Level ◽  
Vibration Measurement ◽  
Vehicle Transmissions ◽  
Quality Of Transmission ◽  
Level Meter

At present, the common method of testing noise generated by vehicle transmission before delivery is to measure the noise sound pressure level by means of sound level meter. Since the measurement result is susceptible to background noise, the method can only be operated in anechoic chamber. In this paper, in order to measure sound pressure level directly on production-line, a new vibration measurement method and its relevant formula are presented. The proposed method can effectively avoid being affected by background noise and obtain the sound pressure level of transmission noise on production-line by testing the vibration acceleration signals of transmission box. It’s proved that the new method makes the delivery test of transmission noise more convenient and effective. Moreover, it can improve the delivery quality of transmission as well as the performance of whole vehicle.

scholarly journals KAJIAN PENERAPAN SENSOR MIC-CONDENSER DALAM RANCANG BANGUN SOUND LEVEL METER DIGITAL.

JURNAL ELTEK ◽  
2018 ◽  
Vol 16 (1) ◽  
pp. 86
Author(s):  
Achmad Komarudin ◽  
Hariyadi Singgih ◽  
Moh. Luqman
Keyword(s):  
Data Processing ◽  
Sound Pressure ◽  
Motor Vehicle ◽  
Sound Level ◽  
Motor Vehicles ◽  
Sound Level Meter ◽  
Vehicle Exhaust ◽  
Sound Sources ◽  
Level Meter ◽  
Digital Sound

Noise levels in the industrial and urban streets have a threshold value that has been determined by the Regulation of the State Minister of the Environment Number 07 Year 2009 for motor vehicles. And Minister of Manpower Number: KEP-51 / MEN / 1999 for industrial environment. To know the value of noise is required a Digital Level Sound Meter gauge that can be used as a measuring instrument of sound intensity noise value of motor vehicle exhaust and other sound sources. This tool can change the amount of sound pressure converted in LCD display. This Digital Sound Level Meter is used to measure the feasibility of thresholds on exhaust and other sound sources. The purpose of this research is to study the application of Mic-condenser sensors in Digital Sound Level Meter design The research method is to design and design the system, using mic condenser sensor, designing signal conditioner using op-amp with series of Absolute Value Modulus (MAV), which can rectify AC voltage into DC using Microkontroller ATMega 8535 as data processing result of data processing which has become the quantity sound pressure with decibels (dBA) is presented in LCD devices The results of the system test show that this Digital Sound Level Meter can run and can display the sound pressure level captured by the mic condenser sensor, and from the result of the Digital Sound Level Meter test compared to the comparison tool obtained an error of 2.94%.

The Use of Sound Level Meter Apps in the Clinical Setting

2016 ◽  
Vol 25 (1) ◽  
pp. 14-28 ◽  
Author(s):  
Gaetano Fava ◽  
Gisele Oliveira ◽  
Melody Baglione ◽  
Michael Pimpinella ◽  
Jaclyn B. Spitzer
Keyword(s):  
Clinical Setting ◽  
Sound Pressure ◽  
Sound Level ◽  
Healthy Adults ◽  
Anechoic Chamber ◽  
Fort Worth ◽  
Sound Level Meter ◽  
Pure Tones ◽  
Level Meter

PurposeThe purpose of this study was to compare sound level meter (SLM) readings obtained using a Larson-Davis (Depew, NY) Model 831 Type 1 SLM, a RadioShack (Fort Worth, TX) SLM, and iPhone 5 (Apple, Cupertino, CA) SLM apps.MethodIn Procedure 1, pure tones were measured in an anechoic chamber (125, 250, 500, 1000, 2000, 4000, and 8000 Hz); sound pressure levels (SPLs) ranged from 60 to 100 dB SPL in 10-dB increments. In Procedure 2, human voices were measured. Participants were 20 vocally healthy adults (7 women, 13 men; mean age = 25.1 years). The task was to sustain a vowel “ah” at 3 intensity levels: soft, habitual, and loud. Microphones were lined up equal distances from the participant's mouth, and recordings were captured simultaneously.ResultsOverall, the 3 SLM apps and the RadioShack SLM yielded inconsistent readings compared with the Type 1 SLM.ConclusionThe use of apps for SPL readings in the clinical setting is premature because all 3 apps adopted were incomparable with the Type 1 SLM.

scholarly journals Acoustic and Flow Aspects of Novel Synthetic Jet Actuator

Actuators ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 100 ◽  
Author(s):  
Emil Smyk ◽  
Paweł Gil ◽  
Rafał Gałek ◽  
Łukasz Przeszłowski
Keyword(s):  
Sound Pressure Level ◽  
Sound Pressure ◽  
Optimal Solution ◽  
Sound Level ◽  
Pressure Level ◽  
Synthetic Jet ◽  
Acoustic Properties ◽  
Synthetic Jet Actuator ◽  
Flow Parameters ◽  
Level Meter

The acoustic and flow aspects of the novel synthetic jet actuator (SJA) with fins inside the cavity were experimentally investigated for three types of enclosure design and two models of loudspeaker. The aim of the study is to find the parameter which connects the flow and acoustic properties of the SJA and allows us to choose the optimal solution in those regards. The hot wire anemometry was used for the velocity measurements and the sound pressure level was measured with a sound level meter. The model of the loudspeaker turned out to have a significantly stronger impact on the flow parameters and noise level than the shape of the fins in the cavity. The parameter that showed a dependence on the shape of the fins was the actuator’s efficiency. A ratio of the root-mean-square velocity at the orifice axis to the sound pressure level (U0.c/SPL) was used to connect the acoustic and flow properties of the tested actuators. This parameter was subsequently applied to determine the best configuration among the tested actuators.

scholarly journals The assessment of the sawmill noise

2013 ◽  
Vol 44 (2s) ◽  
Author(s):  
P. D’Antonio ◽  
C. D’Antonio ◽  
C. Evangelista ◽  
V. Doddato
Keyword(s):  
Data Processing ◽  
Sound Pressure Level ◽  
Noise Level ◽  
Sound Pressure ◽  
Sound Level ◽  
Pressure Level ◽  
Published Data ◽  
Noise Levels ◽  
Different Types ◽  
Level Meter

Noise is a serious and widespread problem in many workplaces like in sawmill. The published data for the year 2010 about the total number of pathologies from work in Italia due to the noise, showed 5222 cases divided by sex, in fact for females there are instances in number of 221 while the male has a number of cases is equal to 4961. The aim of this work was to detect the sound level caused by the use of the machineries in a sawmill. The measurements were carried out through an instrument known as noise level meter, equipped with a microphone and connected to a computer for data processing and analysis of variance to a factor in excel, and able to assess noise levels at any particular point in the mill. The machines were subjected in relief and with several different types of wood materials. Obviously, in our case a fundamental role takes the moisture of wood. The drying operation is intended to obtain that degree of humidity of the wood, generally it must be between 7 and 16%, compatible with the type of glue used and, above all, appropriate to the target structures. The machines that have the highest sound pressure levels were trimmer and profiler, with values ranging between 85 dB(A) and 110 dB(A). Finally, it’s possible conclude that the sound pressure level increases when the aspiration equipment is turned on, the noise of machinery decreases during the processing of wood and that, increasing the thickness, decreased the noise emitted by the machine.

Study on audiometer calibration at the extended high-frequency range 8–16 kHz

2021 ◽  
pp. 095745652110526
Author(s):  
Tarek M. El-Basheer
Keyword(s):  
Hearing Loss ◽  
High Frequency ◽  
Sound Pressure ◽  
Uncertainty Estimation ◽  
Sound Level ◽  
Pressure Level ◽  
Physical Parameters ◽  
Frequency Range ◽  
Measurement Traceability ◽  
Level Meter

Audiometry is a branch of acoustical measurements that concentrated on testing the devices related to hearing and used in medical part such as audiometer. It is substantial to calibrate the audiometer to assure the measurement traceability and to safe human health. So, it is considered as a major claim. The importance of calibration comes from the request for advanced instrument to test accurately the hearing loss for human, especially for those people who might be at risk due to noise. The conventional audiometry covered from 125 to 8 kHz, while the extended high-frequency (EHF) audiometry above 8 up to 20 kHz, the last-mentioned type may be useful in early diagnosis of hearing loss. The audiometer calibration performed using ear simulator, standard or working microphone, sound level meter, and frequency analyzer according to IEC60645-1. The physical parameters such as sound pressure level, frequency and distortion may be affected by environmental conditions such as temperature change. The gained results observed that the measured value of all the tests performed was affected by temperature variation. There were deviations observed from each performed test’s nominal values in the calibration process as the temperature varies from 16 to 40°C. So, this is a detailed study for the significance, method, and uncertainty estimation for audiometer calibration covering the EHF ranges within the temperature from 16 to 40°C.

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