Abstract: An analogue probe for a machine tool apparatus, which includes a probe body, a stylus member movably secured to the probe body and a sensor that measures the extent of displacement of the stylus member relative to the probe body, in which the sensor is contained within a chamber in the probe body. The analogue probe further includes a vent between the chamber and the outside of the probe body, configured such that, when the vent is open, the pressure within the chamber can equalize with the analogue probe's operating environment's pressure, and is further configured such that the vent's opening to the outside of the probe body can be closed so as to seal the chamber and the sensor from external contaminants during operation of the analogue probe.

Abstract: An analogue probe for a machine tool apparatus, which includes a probe body, a stylus member movably secured to the probe body and a sensor that measures the extent of displacement of the stylus member relative to the probe body, in which the sensor is contained within a chamber in the probe body. The analogue probe further includes a vent between the chamber and the outside of the probe body, configured such that, when the vent is open, the pressure within the chamber can equalise with the analogue probe's operating environment's pressure, and is further configured such that the vent's opening to the outside of the probe body can be closed so as to seal the chamber and the sensor from external contaminants during operation of the analogue probe.