Abstract Two previous generations of RZB borehole strainmeters carry the measurement based on the transformer bridge consisting of the ratio arms and two differential capacitences of the transducer. The insitu calibration of the strainmeter was achieved by manual electric calibration methord. Because being unable to realize insitu calibration without the ratio arms the third generation of RZB borehole strainmeters using digital capacitance displacement transducers is unqualified for the technical requirements of instruments in network for earthquake monitoring. For these digital capacitance displacement transducers the research on new micro displacement calibration technique choosing REMA Magnetostrictive Alloys is carried through recently, the configuration and primary experimental results of new regulator are introduced and causes resulting in calibration error are also discussed.
