Touch Probes

Touch Probes have a measurement tip attached via several lymbs and joints. The location of the tip relative to the base can be calculated by knowing the lymb lengths and the joint angles.

The configuration of the number of joints and lymbs will determine the reach and the ability of the touch probe. Touch probes can range from small desktop models capable of measuring 50" sphere up to large industrial models that can measure up to a 12' sphere. They typically have up to seven degrees of freedom. Optical encoders are used at each joint to determine the angle.

An advantage of touch probes is that they are intuitive to use. You move the tip to the location you want to measure, and tell the computer to acquire a point. Touch probes can reach behind and into objects. The disadvantage is that it can time-consuming to measure a lot of points. If the tip used is not a point, then offset calculations are required.