Vertical centrifugal pumps are provided in fast reactors for circulating the primary coolant and flow measurements in these pumps are done using Eddy Current Flow Meters (ECFM). ECFM is an assembly of Outer and Inner Guide Tube (IGT) and a probe that needs replacement after every five years of operation. IGT is a nine meter long, slender component that requires blind insertion through intermittent supports in the pump’s stationary portion. IGT, being flexible, may miss out on its supports during assembly, leading to errors in flow measurement, undesired flow-induced vibration, and stresses. In-situ vibration measurements were conducted to ensure proper assembly of the IGT. The experimental results were then compared with analytical ones obtained using finite element based models to confirm the number of supports acting on IGT. This paper describes the experiments and related analyses, with the help of which vibration characteristics of ECFM assembly are understood and a conclusion on the state of IGT supports is reached.