I think this is not correct. No need to subtract anything.. Apply the load and wait 10 sec. remove the load and find out the hardness directly. That s it.. Pls don't follow this.
@@Pageskeptunturned you described in your vedio that small circle in the dial as C scale. That is not at all a scale , that is an indication for a minor load to fix the intender and the job. In this dial when the pointer reaches the red point it is meaning a 10 kg load is applied , that is to fix the material to the intender. C scale outer most black dial with diamond indender with 150 kg load. As you mentioned no difference in reading is not to be calculated the final position after releasing the load is the reading. HRc _ 150 kg diamond indendet HRb_100kg load steel ball indender HRa_60kg load diamond indender.
