Can someone tell me how to use a Sound Card as A/D Converter? How can I plug for instance: an impact hammer and and accelerometer? How can I do calibration?
Calibration depends on the analyser program you are using. Usually an known vibration level (small shaker) is applied to the transducer and input into the analyzer. My vibration calibrator produces 1g (10 m/s2) and I set my program to read 10 m/s2 at that input voltage.
If you use your sound card it usually uses a stereo mini-phono plug. you will need to wire up bnc connectors (or whatever) to the stereo mini-phono plug (2 channel).
If you are doing hammer measurements and other advanced 2 channel analysis, be careful to determine an estimate of the phase lag between your channels. If it is too far out, you may not get reliable measurements.
C. Hugh (
maybe a bit to late, but you can download a program called "wav2txt.exe". This program converts a wav file to a txt file that can be read by Excel. Just search for the name of the file with e.g. Google and you will find it. Of course you should run a virus program on the exe file first!!
Here is freedownload oscilloscope using sound card in the PC.
Any sound card can be used. I am using this for my hobby experiments in electronics. It should also help you
I searched for possible softwares and I/O features. My guess is that a laptop with sound card and "Sound Technology" products; SpectraPRO software and ST219-ICP seems to be feasible for simple -I mean one input, one output- vibrations and acoustics testing and analysis.
What are your opinions about this?
I need also advise for cheap and feasible accelerometre, microphone and impact hammer, which are as precise and accurate devices as the above mentioned systems since much precise or accurate transducer then the acqusition system is meaningless I guess.
Aye, there's the rub. Cheap mic is easy - get one with a reasonably flat frequency response, then calibrate it with your soundcard to compensate for bumps and dips. A useful trick here is to use reciprocity and two identical microphones, one as the sound source and one as the receiver.
Accelerometer - tricky. The knock sensor on a car detects vibration, but it is tuned to a small frequency range. You could try building a seismic mass onto a microphone and then using that as an accelerometer.
Load cell - don't know how to do this cheap, maybe a strain gauge based system?