StrataGem

Technical Specifications

Operating Principle	Frequency domain tensor EM, natural and controlled source
Operating Range	10 Hz to 100 KHz, low frequency option available
Transmitter	Model TxIM2 with Vertical loop antenna
Transmitter range	1 KHz to 70 KHz
Antenna Moment	400 amp -msq, Larger moment antenna available (6000 amp.msq)
Visual Output	1D soundings and 2D Sections for in-field QC, 2E fields and 2 H fields
Electric Sensors	Four Model BE26 Buffered , active high frequency dipole, 26m cable with four stainless steel electrodes
Magnetic Sensors	Two model BF1M Magnetic Field sensors (10 Hz to 100 KHz with 10m cable. Note Low frequency options available (0.1Hz to 1KHz)
ADC resolution	18 bits

Power requirements	1. Transmitter -12 VDC 2. Receiver Console and AFE - 12 VDC
Environmental	Temperature: -0 C to +50C Will operate below Zero but specifications not guaranteed
Shipping Weight	Approximately 200 kgs

The Stratagem EH4 uses the magnetotelluric (MT) method to measure subsurface conductivities. The MT method is based on the fact that the ratio of the magnetic field to the electric field at a given frequency is a constant for a constant resistivity. The StrataGem, uses natural fields created by lightening strikes and is augmented by a field generated by a local transmitter, shown above. Compared to other MT systems, because the StrataGem is operating at relatively high frequencies, the Stratagem is quite a rapid tool ,with data acquisition , once a station is established taking of the order of 5-10 minutes.

Data is visually presented on the screen of the console, and once two or more stations have been acquired a 2D section can be drawn on the screen for in-field QC of data.

Applications include:

Groundwater surveys

Depth to bedrock

Engineering and environmental studies

Geological structure mapping

Mineral Exploration

EM and MT Research

StrataGem Analogue Front End with E and H field sensors

Stratagem console with typical QC screen

Geometrics main