Crack depth measurements are used to determine if a part can be economically repaired or possibly to determine if a shaft or other component may remain in service while a replacement part obtained.
The Karl Deutsch RGM 4015 crack depth gauge measures crack depths on workpieces of iron, ferrous and austenitic steels and can also be used for cracks in copper, brass, aluminium and other non-ferrous metals.
The RGM 4015 uses the electrical potential principle: A probe with four spring-loaded, gold plated, contact pins is positioned across the crack to be measured on the workpiece. A constant alternating current is passed via two of the pins into the workpiece; the two other pins measure the voltage drop across the crack from which the depth of the crack is derived. The alternating current creates a skin effect, which forces the current to follow the surface of the conductor and therefore follows the contour of the crack. The instrument compares the change in current on between a good area and compares it with current over a crack. The amount of change is proportional to the crack depth.
1- RGM 4015
1- Carrying case
1- Interface cable
1- RMSQ 0 degree Probe
1- Calibration block, 0 to 10 mm crack depth