Abstract: In order to measure the corrosion rate of metal bars precisely and quickly，a

MZ interferometer is used to monitor the processing of the dynamic corrosion process. The

corrosion rate of metal bars can be evaluated with ultra-sensitivity even when the

concentration of NaCl solution is only 0.05 wt%. It is found that the sensitivity response is a

function of the effective refractive index ( RI) . The experimental results reveal that the

speeds of the wavelength shift is up to -9.32×10-² nm / s，and the increase of the peak intensity

is about -3.93×10-² dB / s. Mo- reover，the electrochemical technology is used to accelerate the

corrosion process. And the whole process could be monitored within 1 min. This experiment can

be used as the extension experiment or innovative experiment of the

metal linear expansion coefficient experiment.

Key words: corrosion process, MZ interferometer, electrochemical technology