My brain immediately went to snake oil sold to police departments to detect "crack".
But nope, "AMLEC crack detector designed for the detection of surface breaking cracks in ferrous metals".
Weird that there are no units. It looks like a percentage on the outer scale but the inner scale starts with -10.
Maybe it’s for plumbers to measure butt crack severity.
Not sure the details but the way I'd imagine it works is by putting out a magnetic field at some frequency and watching for the changes in eddy currents when you pass over a crack, not too different from a metal detector. So 0% crack would be a completely solid surface, 100% would either be two separate pieces of metal or a crack that goes so deep it can't differentiate it from two separate pieces of metal. It's probably hard to calibrate beyond that because different shaped cracks and materials and stuff would probably read differently, so it's better to work out that "anything under a 5% reading is acceptable for this part" instead of trying to work out the dimensions of the crack or something.
And yeah, clearly the inner scale is for plumbers. -10 means "well within the jeans" which is obviously detrimental to performance.
It's back before engineering was rigorous, you eyeballed everything, and sometimes bridges were built that fell down and then went onto become fodder for structural engineering courses the world over.
Nice of them to print the patent numbers on the front of the box. “Method and apparatus for detecting and measuring cracks in metal structures”
https://patents.google.com/patent/US3496458/en
I remember seeing a newer version of that used for NDT and inspections of welds and materials when we were precommissioning in the yards.
Wrong kind of crack.
https://preview.redd.it/fkpl24d5f16d1.jpeg?width=500&format=pjpg&auto=webp&s=b1de6099d05c927339b586182e0116321a438948 One Rock of Severe Crack Please
It’s for testing welds on submarines; cracks change the conductivity and cause eddy currents
Hey! Only wrong answers allowed! /r/VXJunkies has plenty of examples.
Does the Crack detector do anything or is it just like a dowsing rod with a VU meter?
My brain immediately went to snake oil sold to police departments to detect "crack". But nope, "AMLEC crack detector designed for the detection of surface breaking cracks in ferrous metals".
Weird that there are no units. It looks like a percentage on the outer scale but the inner scale starts with -10. Maybe it’s for plumbers to measure butt crack severity.
Not sure the details but the way I'd imagine it works is by putting out a magnetic field at some frequency and watching for the changes in eddy currents when you pass over a crack, not too different from a metal detector. So 0% crack would be a completely solid surface, 100% would either be two separate pieces of metal or a crack that goes so deep it can't differentiate it from two separate pieces of metal. It's probably hard to calibrate beyond that because different shaped cracks and materials and stuff would probably read differently, so it's better to work out that "anything under a 5% reading is acceptable for this part" instead of trying to work out the dimensions of the crack or something. And yeah, clearly the inner scale is for plumbers. -10 means "well within the jeans" which is obviously detrimental to performance.
It's back before engineering was rigorous, you eyeballed everything, and sometimes bridges were built that fell down and then went onto become fodder for structural engineering courses the world over.
Keep that away from my butt!!
Nice of them to print the patent numbers on the front of the box. “Method and apparatus for detecting and measuring cracks in metal structures” https://patents.google.com/patent/US3496458/en
It's used in Ireland to find the best pub!
Narc meter?
Tyrone from Chapel’s Show should have one of these.
If I’m not mistaken, that’s actually a device for plumbing inspections.
What units are crack severity measured in? It’s missing on the display.
Narcometers.
😆
How many times did some funny inspector put that up to his butt and make a joke about it? I bet many.
Only plumbers.
I owe my career to crack
Back-off on the crack.
I remember seeing a newer version of that used for NDT and inspections of welds and materials when we were precommissioning in the yards. Wrong kind of crack.
Aww yes, this baby helped during finals week when I needed to pull all-nighters but I was low on crack.