Need assistance finding a decent Ultrasonic Thickness Gauge for gold verification

[Gold Brain]

So as the title says I am looking at an Ultrasonic thickness meter / gauge in comparison to the magnetic test.

For 184 USD I found a TM8812 Ultrasonic Thickness Gauge on amazon, but then combining the calibration block and the couplant gel pushes the total price range to about 300 USD.

1 How many of you use these devices on your bars? It’s my understanding there’s really not much of a substitute other than a paramagnetic vs diamagnetic test and if that is sufficient enough it would be significantly cheaper, but I would prefer to do them both. Even a specific gravity test would not be sufficient for determining gold with Tungsten.

It appears the only device I can find is the one listed above and it seems the gel and calibration is obviously necessary.. I guess my main concern is if this is overkill, and since I only buy them from reputable dealers, Apmex, etc.. not sure if I need it or not. here is the magnetic test I referenced above in action, it’s a little different but maybe could serve as a substitute https://m.youtube.com/watch?v=foELQ7T8_90

[RandomMan06]

For coins, you come a long way with measuring weight, specific gravity and dimensions. If you add a resonance test, do a visual inspection and buy it from a reputable dealer, i would say you are quite safe.

The safest coin option should be the new gold maple as its design is hard to fake. I'm not sure if there is good data on the resonance of these coins available, but you can download a phone-app that has the reference data.

As for bars, i don't know. I don't like them because of the security issue.

Unfortunately, this forum is too busy posting gold prices every hour in 10 different threads

[Gold Brain]

For coins, you come a long way with measuring weight, specific gravity and dimensions. If you add a resonance test, do a visual inspection and buy it from a reputable dealer, i would say you are quite safe.

The safest coin option should be the new gold maple as its design is hard to fake. I'm not sure if there is good data on the resonance of these coins available, but you can download a phone-app that has the reference data.

As for bars, i don't know. I don't like them because of the security issue.

Unfortunately, this forum is too busy posting gold prices every hour in 10 different threads

I’ll do more research and post it here, I have a few bars all from large reputable dealers that would benefit from the extra testing although I’m not concerned in the least, just figured it couldn’t hurt.

[RandomMan06]

Sounds like a good idea. If you're too bothered by paranoia you could always drill a hole or cut one in half. Then sell the scrap at a small loss if you know of a place to sell it.

But fancy equipment is always more fun!

[maxwellsilverhammer]

So as the title says I am looking at an Ultrasonic thickness meter / gauge in comparison to the magnetic test.

For 184 USD I found a TM8812 Ultrasonic Thickness Gauge on amazon, but then combining the calibration block and the couplant gel pushes the total price range to about 300 USD.

1 How many of you use these devices on your bars? It’s my understanding there’s really not much of a substitute other than a paramagnetic vs diamagnetic test and if that is sufficient enough it would be significantly cheaper, but I would prefer to do them both. Even a specific gravity test would not be sufficient for determining gold with Tungsten.

It appears the only device I can find is the one listed above and it seems the gel and calibration is obviously necessary.. I guess my main concern is if this is overkill, and since I only buy them from reputable dealers, Apmex, etc.. not sure if I need it or not. here is the magnetic test I referenced above in action, it’s a little different but maybe could serve as a substitute https://m.youtube.com/watch?v=foELQ7T8_90

from my understanding and previous research (never personally bought or used) this TM 8812 is a decent tester, BUT... BEWARE. chinese knock off counterfeit units are out there and just make sure you can get one from the original mfg, not the counterfeit version, good luck

[Gold Brain]

from my understanding and previous research (never personally bought or used) this TM 8812 is a decent tester, BUT... BEWARE. chinese knock off counterfeit units are out there and just make sure you can get one from the original mfg, not the counterfeit version, good luck

Thanks for your response, it seems they can make knock offs of anything these days.

I guess I was hoping a good magnet and sensitive scale could also be used for smaller bars in place of the Ultrasonic meter. From googling it appears gold is Diamagnetic ( slightly repelled by a magnetic field ) and tungsten is paramagnetic ( attracted to a magnetic field. )

So instead of the usual magnet test such as placing it on the table and seeing if it moves, with this test you place it on top of a scale above a magnet and measure the difference with the scale.

https://m.youtube.com/watch?v=foELQ7T8_90

“ Gold is diamagnetic, it does not get attracted by neodymium magnets, it even pushes against them, hence the positive scale reading. Iron and tungsten do get attracted by the magnet, resulting in a negative reading. “

The other reason I would prefer this kind of test over the Ultrasonic ( if it’s reliable ) is because unlike the electronic device it wouldn’t be easy to break, really all we would need is the magnet, stand, and scale, and in theory it should detect tungsten all the same, I would think.

[4DSJW]

Do a search for posts by redmonster. Lot's of good information on this subject.

[Gold Brain]

Do a search for posts by redmonster. Lot's of good information on this subject.

I saw some references to frequency tests on gold maple coins but not much to do with Ultrasonic devices etc.. right now I’m also looking at the precious metal verifier which seems like a hyped modified version of the magnetic measuring test I saw in the video.

[RandomMan06]

I saw some references to frequency tests on gold maple coins but not much to do with Ultrasonic devices etc.. right now I’m also looking at the precious metal verifier which seems like a hyped modified version of the magnetic measuring test I saw in the video.

He posted some good stuff on magnetic testing as well... unfortunately you either need a precise scale or a very strong magnet to use the setup. And still the readings were quite low i.e vulnerable to errors/noise. Lastly he did not have a fake coin/bar to validate the method.

[LongDonSilver]

Has anyone tried using the ~$50 eBay Chinese GM100 ultrasonic testers? They claim 2.5mm to 220mm and it has 12 velocity settings per the Chinglish manual. For "Glod" is says to use 3240 m/s and Silver - 3600 m/s and so I assume (I know) that it should/could/might work for testing.