1. A method for calibrating an arbitrarily oriented non-contact measurement sensor that is pre-calibrated and includes a structural light source and optical sensing means, with respect to an external coordinate system, the method comprising: using the structured light from the sensor to create a target lying simultaneously within a measuring zone of the sensor and a measuring zone of measuring means external to the sensor; using the sensor to determine first spatial coordinates of the target expressed in terms of the sensor's coordinate system; using the external measuring means to determine second spatial coordinates of the target expressed in terms of the external coordinate system; and transforming the first spatial coordinates into the coordinates expressed in terms of the external system using the first and second spatial coordinates of the target.