EM31-MK2
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
Description
Technical Specifications
Power source
8 disposable alkaline “C” cells (approx. 20 h continuous)
Dimensions
Boom: 4m ext.; 1.4m stored
Case: 145x38x23 cm
Weights
Instrument: 12.4 kg;
Shipping: 28 kg
Acquisition
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
