In order to investigate the response law of different interferometers to the mid-spatial frequency errors and obtain the relatively true power spectral density (PSD) distribution, the 4D AccuFiz, ZYGO DynaFiz and ZYGO GPI interferometers are respectively used to measure the periodic ripples and scratch samples, and the comparative analysis of the measured one-dimension PSD curves is made. The results show that the responsivities to the mid- and high-spatial frequency information are different for different interferometers, and the higher the interferometer resolution is, the higher the responsivity is. The instrument transfer function (ITF) curve is used to correct the measured PSD, and the truer PSD distribution is obtained. However, in the range of some frequency bands, there still exist some difference between the ITF curve and the practical response.