Hi guys,does anyone know what a ultrasonic thickness gauge needs to be set at when checking a Krugerrand ? Should it be faster or slower than 3240 m/sec (the speed in AU ) or do I use 91 % of the speed in AU and the rest of CU ? Thanks very much
Never been able to do a successful ultrasonic thickness test on a coin - the transducer head is too big to fit between the relief of the design, and the resolution (0.1mm) is not good enough when testing an item only 2-3mm thick.
I understand the issues.Not sure though how big your transducer head it,mine fits easily on a 1 oz coin.You will get a reading on a coin and I get readings somewhat near the targeted velocity but as you say,it is not precise.That brings us to the question if we can allow for a acceptable range or a "near enough". Also ,please help me with my original question,if you can.How do you calculate the speed through a disk made up of 91 % Gold and the rest of Copper ? I appreciate your time. Thank you
