Probe assembly and circuit for measuring machine

摘要

A probe assembly has a housing connected to the head of a coordinate measuring machine, a carrier movably connected to the housing, and a piezoelectric crystal mounted on the carrier. A stylus is mounted on the carrier. An electronic circuit receives signals from the crystal and, at an adjustable threshold value, the circuit provides output signals which are greater than and substantially simultaneous with signals from the crystal. A timer maintains the output signal for a time interval after the signal is produced by the crystal.