Re: DQA of wire rope inspection. : If I use 24-30 sensor for detect leakage flux.What kind of the spec of a/d card that I should select.. Please, guidline for my decision. : Thank you. : AxlZ W. AekZ .
For 24-30 flux leakage sensors you'd obviously want at least the 30 channels, maybe more. The sampling rate is another concern, which among other things would be governed by how quickly your system moves along the wire rope or vice versa (basically how much the magnetic field will vary with time), type of sensor, etc.
I'd recommend either the AT-MIO-64E-3 or the PCI/PXI-6071E from National Instruments (http://www.ni.com). Each of these boards has 64 analog inputs, which would be handy because you could then use differential inputs (two channels per sensor) for better signal quality. Of the three, the PCI and PXI boards have the best sampling rate of 1.25 MSamples/s, although the AT board will be a little less expensive. I've used the AT board with 30 magnetic sensors for a magnetic sensing system I designed forpipelines and it worked well even with the lower sampling rate.
Hope this helps-if I can offer any more insight let me know.