acoustic measurement Articles

  • Sarakasi Theatre - room acoustical measurements and modelling

    Measuring Reverberation Time and Speech Intelligibility using Balloons and an MP3 Player as External Sound Sources The non-profit organisation Sarakasi Trust owns a theatre in Nairobi Kenya, inside the former Shan Cinema. In this theatre, youths from the city slums are trained to be acrobats, so that they learn how to make a living without having to resort to crime. Shows and concerts are ...

  • Cam correlation analysis using Acoustic discharge measurement

    The low head hydro power plant in Wettingen, Switzerland, is in operation since 1933 and no effective cam optimization has been carried out up to now. The goal of the measuring campaign was to provide data enabling an economic study for a retrofit and upgrade project of the plant and the measurement of the efficiency improvement of turbines after refurbishment. The contribution discusses cam ...


    By HydroVision GmbH

  • Measuring the Dispersion Coefficient with Acoustic Doppler Current Profilers

    Abstract: A method is evaluated for estimating the longitudinal dispersion coefficient K from velocities and bathymetry measured with an acoustic Doppler current profiler ADCP. If shear dispersion controls the mixing, the dispersion coefficient can be estimated from measurements of velocity and depth in a cross section. The dispersion coefficient has typically been measured by costly and ...


    By Teledyne RD Instruments

  • Dynamic rotary torque measurement using surface acoustic waves

    The subject of torque measurement has previously been addressed extensively. Most of the existing transducers either rely on low voltage analogue systems (e.g. conventional resistive strain gauge) or complicated mechanical assemblies by physically assessing displacement, i.e. optical systems. This paper identifies a new, potentially low cost, non-contact, frequency domain strain torque sensor1 ...


    By Sensor Technology Ltd

  • A Guide to Noise Measurement Terminology

    There are 100s of different acoustic parameters that can be used during your noise measurements. Each parameter can tell you something different the noise you’re monitoring. How do you remember what all this noise measurement terminology means and what it does? We’ve already covered ...


    By Cirrus Research plc

  • Enhanced acoustic material testing in a tube

    Demands from the Industry   A growing number of customers demand quieter vehicle cabins, and cabin acoustic comfort has become a major concern for the automotive industry. Optimization of the acoustic insulation performance has, therefore, been given a more prevalent role in the design process. In the aircraft industry, acoustic comfort for customers and the use of new, lighter ...

  • Fine-tuning acoustic isolation in buildings

    ACCIONA Infrastructure is ranked among the leading construction companies in the world - and is recognised for implementing the most advanced and innovative technology.  As research and design is vital to keep the company at the cutting edge in relation to technological developments, ACCIONA Infrastructure created a team to analyse noise and vibration. Where traditional ...

  • Level Measurement Problems crushed

    Pulsar non-contacting ultrasonic level measurement equipment copes even with the harshest and noisiest conditions, as this case study looking at stone crusher level measurement proves. Pulsar supplied Level Star non-contacting ultrasonic level measurement to Croft quarry in Leicestershire to control stone level in choke-fed tertiary crushers. The Level Star provides relay closures to control the ...

  • OTT ADC measurement - Germany

    Background As the open pit Cottbus Nord is making use of the water of the ponds in the protected landscape of Lakoma (a village 6 km from Cottbus) the Vattenfall Europe Mining AG (VEM) as owner of the pit was obligated to take compensation measurements. VEM entrusted the engineers of the gerstgraser Ingenieurbüro für Renaturierung (gIR) in Cottbus with the planning of the ...


    By OTT HydroMet

  • Acoustic performance of a Helmholtz resonator with flow

    The effect of flow on the acoustic characteristics of a Helmholtz resonator is investigated experimentally. An impedance tube set-up has been modified to facilitate the measurement of transmission loss in the presence of mean flow. Acoustic impedance of the resonator is also measured with and without flow, enabling the analysis of this parameter as well. Transmission loss directly measured from ...


    By Inderscience Publishers

  • Calibration – the sure way to accurate measurements

    Calibration   During testing, microphones and accelerometers can change sensitivity or break. They might look intact, but what happens if you continue measuring without having calibrated your transducer? Can you trust your data? Do you have to redo the entire test? In cases of extreme testing you might only have one shot at getting your measurement right as the product gets ...

  • ZE: 908 Acoustic Interface – The simple way to integrate noise measurements in industrial settings

    Cirrus Environmental, a leading specialist in the design and manufacture of environmental noise monitoring solutions provide a specially designed acoustic interface, ZE: 908, which allows users to add a noise measurement capability to an existing process control system. The ZE: 908 is a small, lightweight power supply and acoustic conditioning unit for microphone preamplifiers, it is ideal as a ...


    By Cirrus Environmental

  • Vehicle–road interaction for interior noise measurement and evaluation

    Nowadays, one of the most valuable criteria of vehicle quality assessment is based on acoustic emission levels. A vehicle is judged comfortable depending on the noise levels transmitted inside. Consequently, there is a general attention to the design criteria aimed at improving the structural acoustic behaviour, to comply with the increasingly restrictive ergonomic standard. Therefore, it is ...


    By Inderscience Publishers

  • Distributed Thermal-Acoustic Data Integration

    Silixa has developed a technique called Distributed Thermal Acoustics (DTA) to monitor simultaneously the thermal and acoustic profile along a hybrid optical fibre cable in submarine environments. Using its world leading distributed fibre optic technology (ULTIMATM DTS and iDASTM) Silixa deployed an optical fibre cable along the seabed and across the water column in an active gas seepage ...


    By Silixa Ltd

  • ZE: 908 Acoustic Interface – The simple way to integrate noise measurements in industrial settings

    Cirrus Environmental, a leading specialist in the design and manufacture of environmental noise monitoring solutions provide a specially designed acoustic interface, ZE: 908, which allows users to add a noise measurement capability to an existing process control system. The ZE: 908 is a small, lightweight power supply and acoustic conditioning unit for microphone preamplifiers, it is ideal as a ...


    By Cirrus Environmental

  • Novel method for sludge blanket measurements

    The most widely used methods for sludge blanket measurements are based on acoustic or optic principles. In operation, both methods are expensive and often maintenance-intensive. Therefore a novel, reliable and simple method for sludge blanket measurement is proposed. It is based on the differential pressure measurement in the sludge zone compared with the differential pressure in the clear water ...


    By IWA Publishing

  • Statistical quality control of streamflow measurements with moving-boat acoustic Doppler current profilers

    This technical note presents a new methodology for the statistical quality control of streamflow measurements with moving-boat acoustic Doppler current profilers. The methodology consists of two alternative acceptance criteria: uncertainty-based and residual-based. The former uses the uncertainty and the latter uses the maximum residual as a measurement quality indicator. Application examples are ...


    By Teledyne RD Instruments

  • ZE: 908 Acoustic Interface - The simple way to integrate noise measurements in industrial settings

    The ZE: 908 allows users to add a noise measurement capability to an existing process control system. The ZE:908 is a small, lightweight power supply and acoustic conditioning unit for microphone preamplifiers, it is ideal as a front-end for data logging and analysis systems where a simple and accurate acoustic input is required as an interface between an acoustic transducer and a process ...


    By Cirrus Research plc

  • A new DIRAC measuring speech intelligibility

    History   Speech intelligibility relates to the sound intensity modulations in the talker’s voice, as described by Houtgast et al. [1]. This principle is used to determine speech intelligibility from the remaining modulation at a receiver position, using a modulated noise source at the talker position. The noise spectrum represents that of a human voice, and modulations at ...

  • Verification of SBL models by mobile SODAR measurements

    Models of atmospheric pollutant transport need information about the structure of the atmospheric boundary layer (ABL). The most important characteristics for such applications are the parameterisation of the stable boundary layer (SBL) and the mixing layer height (MLH). Recently, many different schemes have been employed to calculate the SBL height, but there are many problems with applying ...


    By Inderscience Publishers

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