LEMI-424

Product type:
Long-period magnetotelluric station (MTS)

Product description:
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. High-pass filter-free technology of input stages was used in order to let super-long period signals (up to 100.000 second) to pass. The lightning protection unit (at the photo, two models shown left and right, below) allows both the protection against nearby lightning discharges and easy connection of electric lines in the field. Specially developed very low noise LEMI-701 electrodes are recommended (at the photo, upper right), but any other electrode types may be used too.

Highlights:
High resolution and accuracy
Very low noise
4 electric and 4 magnetic channels
Very low temporal and thermal drift
Low power consumption
8 GB SD card
Satellite synchronization
Graphic display with touch screen
USB output
Waterproof plastic case
Two models of lightning protection units to choose

Product image:

Specifications:

  • Frequency band | DC-0.5 Hz
  • Measured range | ±2450 mV
  • Resolution of electric meter along each component (ADC 32 bit) | 2 nV
  • Sample rate | 1 per s
  • SD card | 8 GB
  • Digital output and control | USB
  • GPS timing, coordinates and altitude determination (antenna cable length 3m)
  • Operating temperature range | minus 20 to +60°C
  • Power supply | (5-20) V
  • Power consumption | <0.35 W
  • Weight: Electronic unit | 2.0 kg, Lighting protection unit | 1.1 kg

Product type:
3-Component analog magnetometer

Product description:
LEMI-424 Long-Period MT Station includes as the second unit the vector AM for the precise measurement of Earth’s magnetic field and its variations at land conditions as well as in geomagnetic observatory (at the photo, above). It is produced on the base of flux-gate sensor, all three components of which are implemented in the same body. The electronics is implemented as “black box” PCB with analog output fixed in the same housing which has to be connected to DL. It is also possible to use any other analog registration unit. Very low power consumption of the magnetometer allows using a small buffer battery what is convenient for long-term autonomous measurements in field conditions, where power breaks may often occur.

Highlights:
High resolution and precision
Low noise
Low temperature offset
Temperature channel
Convenience of installation and service
Low power consumption
3 years operational guarantee

Product image:

Specifications:

  • Measured range at analog output | ±65000 nT
  • Frequency band for magnetometer | DC-10 Hz
  • Transformation factor of analog output | 25 µV/nT
  • Noise level at 1 Hz | <= 10 pT/√Hz
  • Temperature drift | < 0.3 nT/°C
  • Components orthogonality error | < 30 min of arc
  • Operating temperature range | minus 20 to + 60° C
  • Power supply | 5 V
  • Weight: sensor with support and 10m cable | 3 kg
  • Length of sensor connecting cable as manufactured | 6 m* (* any other values up to 75 meters are possible to use.)

Additional Information:

LEMI-424_Datasheet.pdf