Chemalloy Subsurface Detector

[Seden]

I was reading some old California Mining Journal articles and this detector written about in 2 part articles. One in 72',73' and 75' and the inventor is Sam Freedman. The detector measured the dielelectric properties of below earth versus frequency. Chemalloy if you remember came out with the solder in the early 1950's and if you type "chemalloy electronics" on Google you'll get some interesting hits like the 2 papers in IEEE so Sam Freedman was a real engineer. Strange thing to me is, in spite of the fact he hand made and sold quite a few of these, you never hear of them today.

I'd like to hear from anyone who knows about this detector.

Randy

P.S. Carl, if you're interested I could scan the articles in and email them to you.

[99thpercentile]

There are some sensors out there that use the dielectric permittivity of the soil in the measurement. Stolar Horizon has a sensor for landmine detection that uses this methodology. Also capacitively coupled resistivity systems such as the OhmMapper by Geometrics and the CORIM system by IRIS instruments operate on this principle. Each method has advantages and disadvantages depending on the soil properties.