Abstract: Measurement apparatus is described that comprises a measurement portion for acquiring object measurements and an output portion for outputting measurement data relating to the acquired object measurements. A deactivation portion is provided for inhibiting normal operation of the measurement apparatus such that output of the measurement data is prevented. The deactivation portion, in use, reads apparatus usage information from an apparatus usage module and inhibits normal operation of the measurement apparatus if said apparatus usage information fails to meet one or more predetermined criteria. The apparatus usage module may be provided as an integral part of the measurement apparatus or as a separate activation button. The measurement apparatus may comprise a measurement probe such as a touch trigger measurement probe.

Abstract: A measurement probe, such as a touch trigger probe, is described that comprises a stylus module attachable to a base module. The stylus module comprising a housing and a stylus holder moveably attached to the housing. The base module comprises a measurement portion for generating measurement data indicative of movement of the stylus holder relative to the housing. The stylus module has an inbuilt failure mode and thereby a substantially predetermined operational lifetime. In one embodiment, the inbuilt failure mode is provided by integrating a battery into the stylus module. Providing a mechanical failure mode in which a component of the stylus module catastrophically fails after a certain amount of usage is also described.

Abstract: A measurement probe, such as a touch trigger measurement probe, is described that comprises a measurement portion for measuring an object and a data transfer portion for receiving data from and/or transmitting data to an associated unit. The measurement device also comprises an authentication module for verifying the authenticity of the associated unit. The authentication module may include a processor for running a one-way hash algorithm. Authenticity may be established using a challenge and response authentication process.

Abstract: Measurement apparatus is described that comprises a measurement portion for acquiring object measurements and an output portion (for outputting measurement data relating to the acquired object measurements. A deactivation portion is provided for inhibiting normal operation of the measurement apparatus such that output of the measurement data is prevented. The deactivation portion, in use, reads apparatus usage information from an apparatus usage module and inhibits normal operation of the measurement apparatus if said apparatus usage information fails to meet one or more predetermined criteria. The apparatus usage module may be provided as an integral part of the measurement apparatus or as a separate activation button. The measurement apparatus may comprise a measurement probe such as a touch trigger measurement probe.

Abstract: A method of measurement using a measurement probe system includes the steps of (i) providing a measurement probe system having a measurement probe to a user, the measurement probe system being suitable for use with co-ordinate positioning apparatus and (ii) monitoring usage of the measurement probe system.

Abstract: A measurement probe, such as a touch trigger probe, is described that comprises a stylus module attachable to a base module. The stylus module comprising a housing and a stylus holder moveably attached to the housing. The base module comprises a measurement portion for generating measurement data indicative of movement of the stylus holder relative to the housing. The stylus module has an inbuilt failure mode and thereby a substantially predetermined operational lifetime. In one embodiment, the inbuilt failure mode is provided by integrating a battery into the stylus module. Providing a mechanical failure mode in which a component of the stylus module catastrophically fails after a certain amount of usage is also described.

Abstract: A method and apparatus are disclosed for providing a battery low voltage warning for a range of batteries having various initial voltages. When a battery is inserted into a battery holder its initial off-load voltage is measured using a microprocessor. The microprocessor selects a suitable voltage threshold, at which the battery is considered to be discharged, from a predetermined number of voltage thresholds. The initial off-load voltage of the battery is used by the microprocessor as a basis for selecting a suitable threshold. An LED warning or the like is used to indicate that the threshold is reached in use. A measurement probe is shown which uses such a method and apparatus.

Abstract: An optical pulse signal from a machine tool measuring probe is received by a photodiode (28). To reduce interference from xenon strobe beacons, fluorescent lights etc., the pulse signal is processed by an AGC amplifier (30) with low frequency signal cancellation, and the pulses are then detected by a threshold detector (32). The threshold of this detector (32) is variable by a circuit (50), in accordance with the overall amplitude of the signal pulses, in order to provide the best rejection of interference pulses.

Abstract: A method and apparatus are disclosed for providing a battery low voltage warning for a range of batteries having various initial voltages. When a battery is inserted into a battery holder its initial off-load voltage is measured using a microprocessor. The microprocessor selects a suitable voltage threshold, at which the battery is considered to be discharged, from a predetermined number of voltage thresholds. The initial off-load voltage of the battery is used by the microprocessor as a basis for selecting a suitable threshold. An LED warning or the like is used to indicate that the threshold is reached in use. A measurement probe is shown which uses such a method and apparatus.

Abstract: A programmable device which produces a plurality of outputs is connected to a controller having less input ports than there are outputs to be received by the controller. To overcome this problem the controller is programmed to send different signals to the device, one at a time, upon receipt of a particular one of which, the device sends back a corresponding one of its outputs. In the specific example described the signals are different sequences of timing pulses.

Abstract: A programmable device which produces a plurality of outputs is connected to a controller having less input ports than there are outputs to be received by the controller. To overcome this problem the controller is programmed to send different signals to the device, one at a time, upon receipt of a particular one of which, the device sends back a corresponding one of its outputs. In the specific example described the signals are different sequences of timing pulses.

Abstract: Described is a device which enables toolsetting on a machine tool. The device includes a light emitting unit (10) and a light detecting unit (14). A light source (30) causes a light beam (12) to propagate from the emitting unit (10) to the detecting unit (14). A light detector (40) detects the presence or absence of the beam. A trigger signal is produced when occlusion occurs and so the position of an object can be determined by reference to the machine's coordinate readings. The beam (12) may be uncollimated and thus provide a device with an easier set-up and a greater resistance to vibration in use. The light detector (40) and/or light source may be protected from contamination by windows (34,44) or a protector having an aperture therein. The light emitting and detecting units each have an aperture for the light beam.

Abstract: An optical signal transmission circuit for a probe is switched on by an optical switch-on signal comprising a burst 42 of pulses having a predetermined length. This is detected by a circuit which discriminates whether an input signal is a genuine switch-on signal or an interference burst 44, on the basis of the duration of the switch-on signal.

Abstract: An optical signal transmission circuit for a probe is switched on by an optical switch-on signal comprising a burst 42 of pulses having a predetermined length. This is detected by a circuit which discriminates whether an input signal is a genuine switch-on signal or an interference burst 44, on the basis of the duration of the switch-on signal.