Hypodermic needles

[greylourie]

Yes. Very nice videos in your channel. Good work.

[chemelec]

For who find it interesting to see the progress of the experiments and tests of the hypodermic needle metal detector can click on this link.

nupi.

https://www.youtube.com/channel/UCeF...B65nZ8i9InqMkA

Nupi, Which Metal Detector are you using in these Tests?

[Koala]

I don't have any hypodermic needles, so I tried some tests with ordinary pins used in sewing.
pin1: 2.5cm long, 0.59mm diameter ... no reaction
pin2: 2.6cm long, 0.65mm diameter ... detected at approx. 12.5mm (0.5")
pin3: 3.4cm long, 0.62mm diameter ... detected at approx. 50mm (2")
pin4: 5.0cm long, 0.78mm diameter ... detected at approx. 76mm (3")

The above are a representative example, although I did find that some smaller pins were more easily detected than certain larger ones. Which seems to indicate that the material composition plays a large part in the detection process.
The detector used in the tests was a Laser Hawkeye set to maximum sensitivity.

Just tried with my IDX with small stainless steel sewing pin 42mm long in all metal mode 130 mm point down and 1/2 that if horizontal.

Don't know how valid pins are as every one I have is slightly magnetic. If you balance one and move another towards is it moves.

One thin metal thing I can not detect at all is the strip in money. Tried older notes and modern £5 and euro notes nothing at all.

[Nupi]

Excellent achievement. Congratulations nupi. Thanks.

Can you say something about stability your current solution in field - do you need frequently to re-tune your current circuit upgrade?

Thanks WM6,
I do not know what exactly you meant. With the Smart,
It depends on the soil and in particular of the humidity. If you go from dry sand to wet grass,
then you have to adjust. In general, he does not like wet grass. I have not tried in highly mineralized
soil but in a bin with wet beach sand (salty) I was able to detect the needle. I will soon make a video.But with my homemade md I have no soil tests done, that's early yet.

[Nupi]

Nupi, Which Metal Detector are you using in these Tests?

The Smart and a Home made, but I still have a lot to improve. These are just simple air tests. There is still a long way to go.

[Nupi]

Yes. Very nice videos in your channel. Good work.

Thanks Greylourie.

[Nupi]

For who find it interesting to see the progress of the experiments and tests of the hypodermic needle metal detector can click on this link.

nupi.

https://www.youtube.com/channel/UCeF...B65nZ8i9InqMkA

[green]

I tried plotting the time constant for a hypo needle a while back without success. I made another coil,(single layer,awg 34 magnet wire, 9/16 inch O.D., about one inch long). Got some data this time, .24 usec time constant( .76 mm x 42 mm needle) Don't have any information on it, need to get one of the test needles. Data is a plot of target recording - reference recording. Had to poke needle inside coil. Sure would like to know how Nupi detects the needles.

[Nupi]

I tried plotting the time constant for a hypo needle a while back without success. I made another coil,(single layer,awg 34 magnet wire, 9/16 inch O.D., about one inch long). Got some data this time, .24 usec time constant( .76 mm x 42 mm needle) Don't have any information on it, need to get one of the test needles. Data is a plot of target recording - reference recording. Had to poke needle inside coil. Sure would like to know how Nupi detects the needles.

To prevent misunderstanding the box by the coil of the Smart is a tool to work the Smart properly.
The box is not "the invention" but a tool, a passive. The important thing is, the changes in the circuit of the Smart.
In the video I show the detection of two needles (Hypodermic needle MD - prototype. Test 1) and the video with
the discrimination of different metals: (Disc discrimination test) are a homemade MD and coil, and without a box.
which is not necessary in my own design.
I started to change several things more in the circuit of the Smart so that I can take away the box.
Wants to make a video. Upcoming Week.
If you can't get the needle I used (I have tried many types and brands) I can them send you free of charge.
I had also like to send them to Carl and George, apparently not interested. I do a lot for people who treat me nice and fairly.

[Qiaozhi]

I had also like to send them to Carl and George, apparently not interested. I do a lot for people who treat me nice and fairly.

Maybe I missed your offer to send me an example needle. Yes, I'm interested.
Please send me a PM.

[sinclairuser]

i have deliberately sat on the sidelines on this one, getting a hobby style detector to detect needles is quite interesting, some of the comments before by users towards nupi were very unfair i feel, since my ax777 professional detector detects them(commercial machine), its not that big a jump to hobby gear, the thing is commercial machines dont discriminate(usually), they have auto GB, and sat threshold.
they from my tests seem to have more grunt too.
maybe starting from an industrial detector design may give you a boost, its possible that hobby detector designs could be treating the signal in such a way that the odds of detecting hypodermics are stacked against you, what you need is an industrial commercial design to start with, then your successful mods need to be implemented onto that design, though from your vids you seem to be progressing.
the main problem is the type of detector required just dont get posted, most interest is in hobby and homespun projects.

[greylourie]

What make is Smart ? Is this a Deeptech Vista ?

[Nupi]

I did my first idea tested a DeepTech Vista Smart. I've bought recently after I had repair it for someone.
I contact KT135 in a PM of are interest to trace the PCB, his reaction was not quite clear to me, but does not matter.
Now I continue with the homemade to improve the discrimination and reject the rest of the targets. I want to try to make the MD as much as possible sensitive voor the needles.

[sinclairuser]

nupi on that last vid link it says account does not exist, others work fine but not that last one.

[Nupi]

nupi on that last vid link it says account does not exist, others work fine but not that last one.

That does not make any sense. Try this.

https://www.youtube.com/channel/UCeF...B65nZ8i9InqMkA