It is well known fact that impact damper is effective to reduce the vibration amplitude. Two different paths are followed for the analysis of dashpot. In the first path, the concept of coefficient of restitution is used assuming two impacts per cycle symmetrically. In the other path impact forces are split assuming periodic impacts into harmonic functions through Fourier series expansion. The main concept of vibration analysis of impact damper is based on impact duration & impact interval. Study of impact damper is essential to reduce the amplitude of vibration so that the structure can be safe against vibration hazards. Mostly researchers adopt duration of contact to be zero. There is no experimental analysis available for the same. So, in this study attempt is made to set up the experiment to determine the characteristic of different parameters of impact damper for the case of periodic steady state vibration. For the experimentation forced vibration is created by unbalance rotating masses. Experimental outputs were studied on Digital Storage Oscilloscope, (DSO). In this paper first experimental set up is explained and in later part effect of speed, clearance and mass ratio on impact interval is explained.