AC-73-DH / AC-72-DH / AC-71-DH Force Balance Accelerometer Features I Applications □ True Electro-mechanical Force Balance Accelerometer □ Built-in compass as well as tilt, temperature and humidity sensors □ Extremely robust downhole housing □ Suitable for borehole diameters of 100 mm and larger □ Proprietary iSensor™ interface □ Dynamic Range 165 dB □ Full Scale ± 0.5, 1, 2, 3 or 4 g □ Bandwidth from DC to 200 Hz □ Earthquake and Structural monitoring □ Ambient seismic noise monitoring □ Oil and gas exploration □ Ocean bottom seismic monitoring Outline The AC-73-DH sensor package is a true electromechanical triaxial downhole accelerometer designed for broadband earthquake monitoring as well as applications requiring highly sensitive and rugged sensors with minimum maintenance and a simple method for periodic testing. The rugged mass suspension moving coil system improves the signal to noise ratio. The magnetic system and capacitive position sensors offer symmetrical controls for the accurate electronic centring of the mass. At rest the accelerometer mechanism is in balance and no electrical output is generated. In case of a ground motion, AC-73-DH yields an electrical output proportional to the current used to keep the mass centred. This output signal is precisely calibrated to provide a signal at the utmost accuracy and with a lowest possible noise level. The symmetrical positioning system incorporated with the force balance accelerometer principle, the accelerometer faithfully keeps its scaling and calibration even under extreme conditions. The DC response allows the sensor to be tilt tested or recalibrated in the field. With the help of the test line the AC-73-DH accelerometer can be completely tested assuring proper operation and accurate acceleration measurement. This test line is internally connected to the external world only when a given command is sent to the sensor to avoid any noise pick-up through the test input. The AC-73-DH is equipped with electronic offset adjustment features that make its installation very user friendly. This powerful feature allows the users to install the AC-73-DH without mechanical offset adjustment and fine levelling. The advanced iSensor™ interface allows easy deployment using built-in hardware like compass as well as tilt, temperature and humidity sensors. The sensor can be powered from 9.5 to 18 VDC source with the advantage that its power input is insulated from the sensor’s electronic ground. This avoids ground loops and reduces noise induced through the power supply.

General Characteristics Configurations: Axes Alignment** iSensor™ interface iSensor™ interface is a state of the art innovative and proprietary hardware and software interface developed by GeoSlG, which allows through its special computer software, the operation, control, logging and data export for the built-in: - compass - tilt sensor - temperature sensor - humidity sensor Full Scale Range: Sensor Element Type: Dynamic Range: Power Power input: Supply Voltage: Consumption: Overvoltage Protection: Nonlinearity: Cross Axis Sensitivity: Bandwidth: Damping: Offset Drift: Span Drift: Full Scale...