摘要 |
A radial gap (22, 22') produced between the turbine housing (8) and the turbine shaft (4) or between the turbine housing (8) and a turbine blade (6) is monitored when a turbine (2) is running. According to the invention, in order to ensure that the radial gap (22, 22') is measured constantly and accurately, a measuring reference point (18, 18') of non-oxidizing material is disposed on at least one turbine blade (6) and/or on the surface of the turbine shaft (4) in order to reflect light from a glass fibre probe (12, 12') which is guided through the turbine housing (8). |