The Design And Research Of The Engine Of Digital Sound Level Meter

This dissertation describes the development of the modern acoustics, related measure standard and equipment at the beginning. The in-hand real-time Sounds and Vibrations analyzer is the current orientation. It is not only small and exquisite but also has good performance on real-time processing, precision, secrecy and extendibility. There are not these kinds of equipment or correlative reports in the country. This dissertation introduces the structures and theories of typical in-hand real-time Sounds and Vibrations analyzer, which is also called real-time digital sound level meter (DSLM). DSLM Engine, including A/D, DSP and their correlative circuits, is the kernel parts of the DSLM. The designation and manufacture of DSLM Engine are the primary research content of this dissertation.This dissertation analyzes the digital processing characteristics and requirements of DSLM Engine, brings forward a new structure and realization scheme of the DSLM Engine based on TMS320C6205 DSP. The design processes, functions and interfaces of every modules, principles and key points of the designation of six layers PCB are all described and discussed in detail. Software development is the key point of DSP, including digital filter, digital transmission, data storage and access, FFT real-time frequency analysis etc., are all discussed deeply and well. The software workflow designation and code programming are also completed.It had cost lots of time and energies in debugging and testing of the hardware and software. Consequently, some problems and disabilities in the first designation have been corrected. Final results shown out that the 1/1 OCT and 1/3 OCT filter, the frequency weight and time weight analysis are all implemented within the frequency band from 3 Hz to 20 kHz. The power dissipation is lower than 0.3 W and the dynamic range is 90 dB, which is much better than the analog devices. In conclusion, the DSLM Engine has fulfilled the expected functions and measured up to the standards, so it can be used into the in-hand real-time Sounds and Vibrations analyzer.