Application of thin reference absorbers namely α-Fe foil, sodium nitroprusside, potassium ferricyanide and potassium ferrocyanide for testing and control of the velocity driving system in the high-quality and -sensitivity Mössbauer spectrometers is demonstrated. The deviation of the absorption line from Lorentzian shape may be considered as indicator of the velocity driving system being out-of-tune. Such an estimation of the differential nonlinearity of the velocity ranges is much more sensitive than that by laser interferometer. This testing and control of the velocity driving system provide the measurements of high-quality and precision Mössbauer spectra and avoid getting the poor spectra with obtaining artifact results.