[en] IH linac is suitable for heavy ion acceleration, because it will have high shunt impedance per unit length for the acceleration of low velocity particles. We are performing the RF measurement on a 1/6 scale model tank following the study on a simplified 1/8 scale model. The aim of series of measurements are a) to obtain the dependence of the shunt impedance on the tank structure, b) to know the resonance characteristics for the various tank structure, which is necessary for equivalent circuit analysis, and c) to study the electric field distribution along the tank axis and to clarify the effect of the tank end structure on the field pattern. Our experimental results show that in a few to several % β region( β: relative particle velocity) the electric shunt impedance Zs of model tank can take the values of the order of 170 -55 [ MΩ/m ] with various structure parameters. (author)