Lviv Centre of Institute of Space Research

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Main features:

bulletHigh resolution and accuracy
bulletLow noise
bullet4 electric + 3 magnetic channels
bulletVery low temporal and thermal drift
bulletLow power consumption
bulletUp to 2 GB CompactFLASH CARD
bulletSatellite synchronization
bullet4-lines digital display
bulletRS - 232 (RS - 422) outputs
bulletMagnetic sensor with leveling facilities
bulletWaterproof plastic case


LEMI-417M digital seven-component magnetotelluric station (MTS) (three magnetic + four electric channels) is intended for the measurement of natural magnetic and electric field components and their variations in laboratory and field conditions. The magnetometer is produced on the base of flux-gate sensor, all three components of which are implemented in the same thermostable housing. The electrometer has four channels with high input resistance and offset compensation, which can operate with any type of measuring electrodes. The electronic unit allows acquisition, processing and storage of data about magnetic and electric fields variations in internal memory and their transmission to the computer via RS-232 (or RS - 422) interface. Built-in GPS receiver provides satellite synchronization of the internal clock and the coordinates of the MTS location. MTS operation algorithm allows organizing both autonomous and synchronous operation of a set of the MTS installed at the studied area. Several sensor options, e.g., tilt compensated sensor, for observatory and laboratory use with leveling facility, hermetically sealed sensor etc. may be selected. We are flexible to adopt every parameter to your needs.

Innovative Aspect and Main Advantages

LEMI-417M major advantages are very low temporal drift and high accuracy of measurements, what makes it especially efficient for deep sounding application. LEMI-417M is high sensitive device, which has unique low power consumption 1W at the maintenance of main technical characteristics at the level of the best word standards.

The station has waterproof housing and can autonomously operate during 6 months and longer in wide temperature range. 

Areas of Application

LEMI-417M is used for deep sounding of the Earths crust and the determination of vertical resistivity profile parameters down to 400 km with the purpose of mineral prospecting and search of earthquake precursors.



LEMI-417M station in the packing box

Main window of  LEMI-417. program


Magnetic variations measuring ranges along each component 70 000 nT
Resolution 10 pT
Noise level at 1 Hz < 10 pT rms
Temperature drift     < 0.2 nT/C
Transformation factor linearity error   < 0.01%
Components orthogonality error < 30 min of arc
Electric voltage total measurement range  600 mV
Resolution 75 nV
Input resistance    10 GOhm
Time of samples 1 s
Samples  averaging (by software) 2, 5, 10, 15, 20, 30, 60
Volume of the removable Compact FLASH memory card (CF FAT16) ≤ 2 GB
Operating temperature range minus 20 to +50 C
Power supply source      12+6-2  V
Power consumption      < 1.2 W
Weight of electronic unit with magnetic sensor 2.7 kg
Length of connecting cable between magnetic sensor and electronic unit 10 m *
Length of connecting cable between GPS antenna and electronic unit 3 m *

Optional: Cu-CuSO4 electrodes (matched pairs).

* - other values possible to realize on demand.

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Last modified: 06-12-2012

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