Pulse Induction History and Theory

[mikebg]

Probably my fault... I think I erroneously said 1917.

Carl, the year it is not your fault. Your words are correct:
"Popular Mechanics, 1917 (I think)"
http://www.geotech1.com/cgi-bin/page...le=history.dat
http://www.geotech1.com/cgi-bin/page...pm17/index.dat

The fault year is not important. There are important faults made in the engraving:

What controls the first operator with the thumb of his left hand?

Why he has no headphones?

He needs headphones for sound control and target identification. Note what is written in the article:
"Experienced men can differentiate between sounds produced by shells and by fragments; their depth also can be calculated."
Why after WW1 this instrument is not produced?
I ask forum colleagues to seek information using French (and other) sources for this instrument and for the professor who devised it. I think 1915 issue of magazine "La Nature" is the source, because of this written by hand on the page:

[Ferric Toes]

Looks like the second man has the control box, and is wearing the headphones?

Eric.

[bklein]

Looks like the second man has the control box, and is wearing the headphones?

Eric.

The front guy was "expendable" (prisoner) and the guy in the rear was in reality way out of shell detonation range. After the war they ran out of front guys so production of the detector stopped.
Kinda makes sense as otherwise why couldn't one guy do the whole job?

[Ferric Toes]

1970. Pulse Induction goes Underwater.

Another important milestone in pulse induction history was the development of diver held underwater metal detectors. PI is very successful in a sea water environment as the delay time between the TX and RX functions enables the conductive response of sea water to be greatly reduced. Jeremy Green, mentioned in the acknowledgements at the end of the pdf article' moved to W. Australia in the 1970's and initiated maritime archaeology in that country. We both worked alongside in the RLAHA, Oxford and I have great memories of the time we spent together in testing the early equipment.

Eric.


http://inadiscover.com/about/our_tea...ars-1/green_j/

[Ferric Toes]

Here is the English version of the Colani paper posted by Proscan (posts 14, 16, 17). Refer to the diagrams in the German article when mentioned in the English text. The section on "Object Information" is interesting and I wonder if it was ever followed through in a practical detector? I had a lab unit with a wide band log amp which confirmed the ferrous and non-ferrous object responses, and of course the 1/t soil response but didn't take it further.

Eric.

Colani 68001.pdf

[mikebg]

Project 1915

We found enough information from French sources for instrument shown in post #58.
http://www.geotech1.com/forums/showt...852#post165852
We have even data how to build the search head. However to order the puzzle, we should read an article published in the magazine "Scientific American". Unfortunately this article we can't find on the Web.
Can anyone help for this?

[Carl-NC]

Hey, it's the same 2 guys! Nice to know they survived at least a year. I will add this issue to my search list, thanks for digging it up.

[mikebg]

Hey, it's the same 2 guys! Nice to know they survived at least a year. I will add this issue to my search list, thanks for digging it up.

Here is the link for above picture:
http://www.scientificamericanpast.co...ci11131915.htm

[Patrick]

The inventor is Professeur CamilleGutton (1872 – 1963) .

After the war was built on the same principlea detector to search for iron pipe named "Alpha".

http://www.e-corpus.org/notices/86284/gallery/1301708

pages : 132J_227 -0770 et 132J_227-0771

[Carl-NC]

Patrick, thank you for posting that article. See the detector in Fig. 2? I own one of those.

[Alexismex]

Merci Patrick pour ce bel article.Thgank you pPatrick for the book
Alexis.

[mikebg]

Patrick, thank you for posting that article. See the detector in Fig. 2? I own one of those.

Carl, I do not want to waste your time, but I'm very interested in the circuit diagram of this machine because it looks like it is a step backwards compared to the machine builded in 1915. Here is attached that circuit diagram (in my opinion). I need a more detailed picture of your machine to see how is adjusted the angle between the poles depending on the operator's height . I'm interested in the design of vibrating interrupter and how seems the capacitor with large capacitance.

In general, to satisfy my desires, you should appoint a curator of your future museum. He will take pictures, draw circuit diagrams and prepare postings for the forum.

Thanks in advance!

[mikebg]

GLOBAL **** !

PLEASE HELP!

A rule of global **** is:
If looking for something in an ocean of information, someone is hiding just what you need.

I'm looking for two pages in La Nature magazine:.
La Nature № 2219 (8 April 1916) missing pages 239 et 240 containing article:

Novelle méthode de recherche des obus non éclatés dans le champs (author Jacques Boyer)

The article is mentioned in the contents:
http://cnum.cnam.fr/CGI/fpage.cgi?4K...25/100/425/0/0

and in the list of authors:
http://cnum.cnam.fr/CGI/fpage.cgi?4K...22/100/425/0/0

Here is the link to previous page 238:
http://cnum.cnam.fr/CGI/gpage.cgi?p1...%2F425%2F0%2F0

and the link to next page 241:
http://cnum.cnam.fr/CGI/fpage.cgi?4K...43/100/425/0/0

Global ****!

[Carl-NC]

Carl, I do not want to waste your time, but I'm very interested in the circuit diagram of this machine because it looks like it is a step backwards compared to the machine builded in 1915. Here is attached that circuit diagram (in my opinion). I need a more detailed picture of your machine to see how is adjusted the angle between the poles depending on the operator's height . I'm interested in the design of vibrating interrupter and how seems the capacitor with large capacitance.

In general, to satisfy my desires, you should appoint a curator of your future museum. He will take pictures, draw circuit diagrams and prepare postings for the forum.

Thanks in advance!

I'll have to decline for now, the unit is in storage and I don't have time to pull it out & mess with it.

[mikebg]

I'll have to decline for now, the unit is in storage and I don't have time to pull it out & mess with it.

This was joke, but serious, you can buy a PDF file for $ 1.95
http://www.scientificamericanpast.com/
http://www.scientificamericanpast.com/1915index.pdf
http://www.scientificamericanpast.co...ci11131915.htm