Testing silver coins with an ultrasonic thickness gauge

[mdbruhn]

Hello all,

here is a question for anyone with coins AND an ultrasonic thickness gauge.

Can you get any kind of meaningful reading off your coins with all the uneven surfaces?

I know it works on a bar, I've tried it. I don't have any coins (yet) I'm favouring bars because it is so easy to test S.G. and speed of sound on any bar with a lot of flat surfaces.

Anyone tried this? any opinions? any thought/comments?

 

[Captain Kookaburra]

Nope.... Need an XRF for coins.

 

[mdbruhn]

Nope.... Need an XRF for coins.

thanks for that info Captain Kookaburra.

Yeah that makes sense, wishful thinking on my part

One other question for you: Will an XRF detect a silver plated lead alloy? :/

 

[Captain Kookaburra]

One other question for you: Will an XRF detect a silver plated lead alloy? :/

It will as long as the the plating is thinner than 30-50 microns.

Coins - No Problems.

Thickly plated Silver over Lead ... Tricky. But that's when you would use your ultrasonic tester.

 

[mdbruhn]

One other question for you: Will an XRF detect a silver plated lead alloy? :/

It will as long as the the plating is thinner than 30-50 microns.

Coins - No Problems.

Thickly plated Silver over Lead ... Tricky. But that's when you would use your ultrasonic tester.

OK, so all I need to do is convince my boss that we really need that XRF machine for testing the secondhand steel we buy

 

[Midnight Man]

Nope.... Need an XRF for coins.

I won't just "say thanks" for brevity here, because that doesn't tell you that I have found exactly as Cap'n Kook has reported - for the thickness guage to work, you must have good, even contact for the sensor - impossible on a coin, and sometimes even challenging on a Perth Mint blob (poured bar), casts work incredibly well, as you've probably found out yourself

 

[goanna]

Nope.... Need an XRF for coins.

I won't just "say thanks" for brevity here, because that doesn't tell you that I have found exactly as Cap'n Kook has reported - for the thickness guage to work, you must have good, even contact for the sensor - impossible on a coin, and sometimes even challenging on a Perth Mint blob (poured bar), casts work incredibly well, as you've probably found out yourself

How about if you did the coin across the diameter, ie edge to edge?

 

[Midnight Man]

How about if you did the coin across the diameter, ie edge to edge?

Have tried it (on 1oz coin), no luck for me, and if the coin has a milled edge, you can most certainly forget it. The problem is that there just isn't enough "meat" on a 1oz coin to measure.

I don't have bigger than 1oz coin to try, so - maybe on bigger coins? Unsure.