The Long-Period Magnetotelluric Station LEMI-424 is composed of two units – Data Logger (DL) and Analog Magnetometer (AM). DL (at the photo above) is developed for the analog signals received both from AM and from electric lines for telluric field measurements digitizing and storage. In order to realize the design of
electric channels major attention was paid to thermal and temporal stability, high input impedance and low drift. Highpass filter-free technology of input stages was used in order to let superlong period signals (up to 100.000 second) to be
measured.