Specialist sensors. In an ND study, a simple data-logging capability may not be enough by itself, depend- ing on the study objectives. Therefore the data logging can be enhanced with specialist sensing equipment. Such sensors can be mounted to the vehicles themselves and linked to the data acquisition system to record information on channels such as pedal position, steering wheel position, road speed, and suspension movement. Specialist sensors cover a large and diverse equipment group and are often tailored to a particular application, vehicle or installation requirement. In almost all cases, if there is a requirement for a specific measurement, then there will be a sensor available to do this. It is worth bearing in mind that specialist sensors can carry problems which can be manifold and complex to resolve. It will inevitably become a trade-off between the re- quirement for a dedicated sensor and the added problems they bring. Common issues with these specialist sensors involve their added cost (sensors can easily cost upwards of 1000 each), the requirement therefore for protecting these sensors and the subse- quent replacement complexity should they become damaged. Furthermore, calibration of high sensitivity sensors can be problematic and their integration into a data acquisi- tion system will almost inevitably be complex.
