Touch trigger probe
As the sensor makes contact with the part, the difference in contact resistance indicates that the probe has been deflected
The computer records this contact point coordinate space
An LED light and an audible signal usually indicate contact
Touch probe assemblies consist of three components; probe head, probe and stylus
Analog scanning probe
Use to measure contour surfaces, complex, irregular
Remains in contact with the surface of the part as it moves
Improve the speed and accuracy