The EM31-MK2 maps geologic variations, groundwater contaminants, or any subsurface feature associated with changes in ground conductivity. using a patented electromagnetic inductive technique that allows measurements without electrodes or ground contact. With this inductive method, surveys can be carried out under most geologic conditions including those of high surface resistivity such as sand, gravel and asphalt.

Ground conductivity (quad-phase) and magnetic suceptibility (in-phase) measurements are read directly from an integrated DL600 data logger (which can be easily removed from the console for data transfer).  Real time (RT) graphical presentation of the data during collection is possible by connecting a computer directly to the RS232 output port on the frond panel with an optional RS232 interconnect cable.

The effective depth of exploration is about six metres, making it ideal for geotechnical and environmental site characterization. Important advantages of the EM31-MK2 over conventional resistivity methods are the speed with which surveys can be performed, the precision with which small changes in conductivity can be measured and the continuous readout and data collection while traversing the survey area. Additionally, the in-phase component is particularly useful for the detection of buried metallic structure and waste material


Technical Specifications

Power source
8 disposable alkaline “C” cells (approx. 20 h continuous)

Boom: 4m ext.; 1.4m stored
Case: 145x38x23 cm

Instrument: 12.4 kg;
Shipping: 28 kg


Measured quantities
1:  Apparent conductivity in millisiemens per metre (mS/m)
2:  In-phase ratio of the secondary to primary magnetic field in parts per thousand (ppt)

Intercoil spacing :
3.66 metres

Operating frequency:
9.8 kHz

Measuring range :
Conduct.:10,100,1K mS/m;
In-phase: +/- 20 ppt

Measurement resolution :
+/- 0.1% of full scale

Measurement accuracy :
+/- 5% at 20 mS/m

Noise levels
Conductivity: 0.1 mS/m
In-phase: 0.03 ppt

Data storage : 10,000 records (2 components); 16,500 records (1 component); ext. memory available