This PhD project aims to develop an on-line measurement device for clearance in steam turbines which can be installed as a standard measuring device without complicated access routes being provided through the casing of the steam turbine. The existing technology is that of a "wear peg" which provides little diagnostic capability. The equipment has to be able to cope with high temperatures and pressures, ideally typical HP steam turbine inlet pressure and temperature of around 180 bar and 540 degrees Celsius. This is beyond conventional electronics, so extremely challenging. Initial designs would therefore focus on typical maximum LP inlet conditions of 380 degrees Celsius and 15bar. This project is to be conducted in the Engineering department at Durham University with a supervision team consisting of experts in electronics, instrumentation and steam turbine technology. The department operates as a unified engineering school and therefore is ideally suited to such an interdisciplinary project.