 | MEIO AMBIENTE / SEG. DO TRABALHO | PRODUTOS NVH | ENGENHARIA NVH | MANUTENÇÃO PREDITIVA | DMA | DEFESA |  |
dBSONIC - BA
Basic Module & Frequency Analysis
The basic module includes
- Sound signal recording and play back
As easy as using a simple tape recorder, press one button and the sound signal is stored to the hard disk. Contrary to a tape or DAT recorder the dBSONIC input can be calibrated! Supports all common sampling frequencies, includes basic sound editing features. - Frequency analysis
Third-octave and FFT analysis (up to 16384 lines) with level versus time-, spectrum- and color spectrogram display. Combined slice/spectrum display. Lin-, A-, B-, C- weighting and Leq. 6 harmonic markers in the spectrogram display. - Tonality Analysis
Tone-to-noise ratio (TNR) and Prominence ratio (PR), more information next. - Project management
Keep the overall view of your data with fast and ergonomic organisation of the measurement files by drag & drop.
The basic module is needed to run the other dBSONIC modules!
- dBSONIC tonality analysis
Tonality Analysis (in dBSONIC-BA)
dBSONIC offers two different approaches to compute the prominence of tonal components : The tone-to-noise ratio and the prominence ratio.
The tone-to-noise ratio (TNR) is defined as the ratio of the power of a tone under investigation to the power of the critical band centred on that tone (excluding the tone power). Masking effects by components from outside the critical band are not taken into account. A tone becomes just audible when its TNR exceeds the masking index av which is on average -4 dB. In dBSONIC the TNR method is applied either according to the new draft of the E DIN 45681- 2002 or to ANSI S1.13-1995.
The prominence ratio (PR) is defined as the ratio of the power in the critical band centred on the tone under investigation to the mean power of the two adjacent critical bands. ANSI S1.13 - 1995 states that a tone is prominent if its PR exceeds 7 dB . For a tone in white noise a PR of 7 dB is equivalent to a TNR of about 6 dB. Both methods are based on averaged FFT power spectrum computation using a Hanning window .
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Medições e Analise de Ruidos e Vibrações
