OMEGA 48 Resistivity System

OMEGA-48 is a multichannel Resistivity system designed for vertical electrical sounding (VES) and induced polarization (IP) methods on electrical resistivity tomography (ERT) technology.

Resistivity system OMEGA-48 consists of

  • Multi-electrode 10-channel Resistivity instrument which includes transmitter, receiver and switching unit connected to current and measuring lines in a single heavy duty cable with waterproof enclosure
  • Two sections of multi-core cable with 24 electrode each
  • Industrial laptop
  • Software for system control, results acquisition, data processing and interpretation
    • developing field measuring protocol, SEQ files,
    • managing measuring process, data collection and storage,
    • visualization and editing field data,
    • automatic data 2D inversion,
    • visualization of inversion results.

Resistivity instrument measures amplitude parameters of output current of the transmitter, electrical potential difference between measuring electrodes (apparent resistivity), time parameters of chargeability (apparent chargeability) determined on voltage decay curve at measuring electrodes after switching off the current:


Number of measuring and current electrodes connected to the multi-core cable 48, the multi-core cable consist of two sections, 24 electrodes each, the unit is located in the center
Number of channels for simultaneous measuring operation 1 to 10. A pair of receiving electrodes for each channel is selected according to protocol
Number of current lines in simultaneous operation 1. Transmitting electrodes pair is selected according to protocol
Electrode spacing 1 to 10 m
Multi-core cable lenght 50 to 500 m (two sections with length from 25 to 250 m)
Signal form direct current bipolar impulses of regulated duration with pauses
Power supply 24 V, external
Operating temperature -20 to +50°C (option down to -40°C)


Number of input channels 1 (or 2 lines) (commutation multi-core cable is possible)
Direct current bipolar impulses of regulated duration with pauses
Impulses duration 0.2048, 0.4096, 0.8192, 1.6384, 3.2768, 6.5536, 13.1072, 26.2144, 52.4288 seconds
Duty ratio 0.2 .. 0.5
Output voltage 30, 100, 300, 500 V
Instability of output voltage under variation of load resistance 1% at most
Output current 10 mA to 5A
Maximum output capacity 0.5 kW (500 V - 1 A, 100 V - 2 A, 30 V - 5 A)
Time for complete current cut-off on active load 10 μs at most
Protection from short circuits on the output


Number of input channels 1 to 10 pairs of dipoles
Input resistance of each channel at least 20 MOhm
Range of measured signals 10 μV to 12 V
Amplitude response of each channel at least 2 to 3 μV
Instant dynamic range at least 90 dB
Voltage of in phase signal on the input 12.5 V at most
Amplification rate of the prime amplifier 1, 10, 100, 1000
Bit length of Sigma-delta analog-digital converter (ADC) 24
Level of in phase interference suppression at least 80 dB
level of industrial interference suppression with frequencies 45 to 55 and 55 to 65 Hz at least 80 db
Operating temperature from -20 to +50°C (option down to -40°C)