The EM61-MK2A is a high sensitivity, high resolution, time domain metal detector suitable for the detection of both ferrous and non-ferrous metal. Typical target response is a single, sharply defined peak, facilitating quick and accurate determination of location. Achievable depth of detection will depend on several target characteristics, with the surface area and orientation of the target of particular importance. A single 200 litre (55 gal.) drum can be detected at depths greater than three metres.

In comparison with the previous-standard EM61-MK2, the EM61-MK2A provides the same feature and performance specifications. Differences between the two models are ergonomic: because the A-model does not include a backpack for system components, the electronics console is mounted on the U-handle, and the battery is positioned in the centre of the coils.

Data from multiple time gates -- three or four, user-selectable -- are recorded to provide a description of the response decay rate, supporting both the characterization and limited discrimination of targets. Data collection is supported by the DAS70-AR Data Acquisition System.

The system can be pushed or pulled as a trailer, by person or vehicle, as either a single unit or an array of multiple units; for multiple unit configurations, options are available to customize component specifications and layout. As may be required, with the addition of a backpack and associated cable set, the system can be carried by a single person with a belt harness.

High Power (HP) Modification
To increase the depth at which any target is detectable, the high power (HP) modification provides an eight-fold increase in the amount of signal received by a standard transmitter coil resulting in significant improvements in the signal-to-noise ratio. Relative to the standard EM61-MK2 (or EM61), the depth of detection for any target will increase between 45% and 80%, depending on target characteristics - (see sidebar Figure; click to enlarge).

Towed Arrays
For a substantial increase in productivity, particularly over larger areas, multiple EM61-MK2A systems can be configured as a single array to be towed behind a vehicle. Data collection is supported by the DAS70-ML Data Acquisition System that can receive data from as many as ten individual inputs simultaneously (e.g. 9 x EM61-MK2A units and 1 x GPS receiver). The DAS70-ML Data Acquisition System sports also on screen navigation displaying actual array span to provide real time control of the coverage area.