A method of identifying a crack in a touchscreen display system includes measuring a distance between a first layer of the touchscreen display system and a second layer of the touchscreen display system, detecting a change in the distance at a portion of the touchscreen display system, identifying a crack in the first layer at the portion of the touchscreen display system based on the change in the distance, and adjusting one or more parameters of the touchscreen display system based on the crack in the first layer.

A method of identifying a crack in a touchscreen display system includes measuring a distance between a first layer of the touchscreen display system and a second layer of the touchscreen display system, detecting a change in the distance at a portion of the touchscreen display system, identifying a crack in the first layer at the portion of the touchscreen display system based on the change in the distance, and adjusting one or more parameters of the touchscreen display system based on the crack in the first layer.

A method of identifying a crack in a touchscreen display system includes measuring a distance between a first layer of the touchscreen display system and a second layer of the touchscreen display system, detecting a change in the distance at a portion of the touchscreen display system, identifying a crack in the first layer at the portion of the touchscreen display system based on the change in the distance, and adjusting one or more parameters of the touchscreen display system based on the crack in the first layer.

An edge detector is provided for determining the axial position of the leading or trailing edge of a rotating blade within rotating machinery. The edge detector includes a set of axially spaced tip detection probes locatable within a casing of the machinery. Each probe is arranged to detect whether or not the blade tip passes over that probe. The edge detector determines the axial position of the edge of the blade as the position of the boundary between those tip detection probes which detect passage of the blade tip thereover and those tip detection probes which detect no passage of the blade tip thereover.