RE: ARC-GEO Data Logger

[Shawn]

I was wondering if anyone had any info on the ARC-GEO Data Logger? From what I gather this unit plugs into the speaker port of a MD. I was thinking how would this work with a mag? You could scan an entire area with a mag and then run a 2-d or 3-d profile? Any thoughts? Anyone see a cheaper way of accomplishing the same goal? Thanks!

[Randy Seden]

Re: RE: ARC-GEO Data Logger

Shawn,

I just receive my ARC-GEO logger and am anxious to try it and and will give a report later on. The logger works off amplitude variations and so you would have to put a F/V converter and vary the amplitude of an audio osc. which I plan to do.

Randy

[Carl-NC]

Re: RE: ARC-GEO Data Logger

The speaker port is probably not the best place to log data. In many detector designs, the audio does not provide the most sensitive signal, so infomation has been lost at that point.

It would be far better to hook the data logger further back in the design. One bonus is that you could simultaneously log the AM & Disc channels, to provide a better idea of metal type. Or, even better, log raw I & Q data for metal ID.

You could add a F-to-V converter to a mag, and log that, but, again, you are losing sensitivity through all those back-&-forth conversions. Make the data logger an inherent part of the mag design.

Everyday Practical Electronics magazine just published a data-logging magnetometer in the July & August issues, based on the same fluxgate sensors I used in my own mag project. The data logger used was published (also in EPE) as a stand-alone design a couple of years ago, and can be built for $50 or so. I don't have permission to post these articles, but the back-issues can be purchased from EPE.

- Carl



EPE Magazine

[jackdetect]

Re: RE: ARC-GEO Data Logger

About MD, you need more then one channel, to provide serious measuring. Vlf data logging, usually take two signals after Lpp: metal and mineral. Pi data logging also taking a couple of signals after Lpp from different periods.
And what about positioning of storing data?
Jackdetect.

[Tim Williams]

Re: RE: ARC-GEO Data Logger

Carl, The reason I use the headphone jack is to make it easy and available for everyone to use. I have a Geophysicist testing the unit now and he will provide a detailed report on it.

The signal level is fine to drive the logger. I may add a boost circuit. Soon you will see the logger inside a great deep seeker.

I will post the report when I get it.

Regards,

Tim Williams