David and Prospectors Gold and Gems are top notch and totally trustworthy. For the Sigma to test properly, the black circle around the main sensor must be filled with the piece being tested. In other words, you can not test a coin that does not fill the black circle on the main sensor. It must be tested with the wands.
Sir, we are glad to have found this video. Which XRF tester brand is that (Olympus)? That's a darn tootin' pricey metal analyzer!! Holey moley!! This is a phenomenal educational video. Thank you , for the education that the Sigma is a verifier used for government minted shapes etc. That clears up a lot of things. So really what it comes down to is the Sigma is actually rather limited.
The Sigma manual says that coins not in a case must be greater than 24mm in diameter to be read accurately by the main sensor. Coins in a case such as an Airtite must be at least 30mm diameter for accurate reading. This means that when you put one of your little rectangular bars of gold on the main sensor, you shouldn’t expect an accurate reading. You should instead be using a wand appropriate for the size and thickness of the coin or bar that you’re testing.
This was really eye opening for me. I was very confused about all the recent stuff going on with silver bars getting wacky readings on the Sigma, but it doesn't seem too unusual for certain types of silver and gold. Thanks for the demonstration and information, it's much appreciated. It's been hard for me to wrap my head around the variances in results, but I guess it's something like a lie detector test. With the right tester and subject it can be nearly flawless, but an unskilled tester or unusual/deviant subject can give unreliable results.
