Thanks Larrin and Steve. We're all about finding out where the fences are for starters. Might be a good idea to begin with a belt grinder. Begin with a short period and light pressure and see if we trip the sensor paste. If not, a considerably longer period with more pressure, then check again etc. Depending on what we see and at what level we see it we may need to call on a good "non-power" man like you Steve.
By the bye. Just had a conversation with someone who maintains that the term we used "detempered" is not really an accurate term. Over heating would simply cause the edge to be tempered again, albeit at a potentially different temperature than the rest of the blade. It would not be as if the edge had lost all of its original temper and hardness simply because, during the grinding process, it was heated to a temperature that approximated its original tempering temperature.
By the bye. Just had a conversation with someone who maintains that the term we used "detempered" is not really an accurate term. Over heating would simply cause the edge to be tempered again, albeit at a potentially different temperature than the rest of the blade. It would not be as if the edge had lost all of its original temper and hardness simply because, during the grinding process, it was heated to a temperature that approximated its original tempering temperature.