Speaker
Summary
The LSP-S4 probe head of the Leitz Infinity Coordinate Measuring Machine (CMM) is a complex assembly which changes its shape when a force is applied on the extremity of the probe tip during a contact measurement. This change in shape provides part of the information about the position of a measured point. A magnetic field may induce a force on some parts of the probe head. The behaviour of the mechanical parts of the probe head is very well-known when used in usual conditions, nevertheless it had never been assessed within a strong magnetic field.
Historically, the CMM were based on contact measurements, so the first trials were to measure the wire’s position with a contact probe tip: the results were not stable and the diameter of the measured circle was found negative as the wire was pushed during the probing. This wire will define one of the axis of the coordinate system of a quadrupole magnet therefore it must not move during the measurements, which is why a non-contact probe tip is required. Several possibilities exist and are being tested for this application, namely LASER sensors such as the KEYENCE, capacitive sensors such as the Wire Positioning Sensors, and optical sensors such as the Precitec Lateral Resolution sensor, the white light Precitec sensor and the SHARP optical switch.
