The discovery of superconductivity in ThCr2Si2 type tetragonal Fe-based compounds (i.e. YFe2Ge2) have generated considerable interest. Recently we found bulk superconductivity in CaPd2As2, SrPd2As2 and CaPd2Ge2 with transition temperature Tc = 1.3 K, 0.9 K and 1.7 K, respectively. Investigations of superconducting properties by electrical resistivity and heat capacity measurements reveal electron-phonon mediated weak coupling type-II superconductivity possibly with a moderately anisotropic s-wave gap. It would be of interest to further investigate the superconducting properties of CaPd2As2, SrPd2As2 and CaPd2Ge2 using muon spin relaxation and rotation (µSR) technique to find out whether the time reversal symmetry is broken or not. We therefore propose to carry out µSR study on these compounds using the MUSR spectrometer.