CG–3/3M AUTOGRAV - Scintrex

Instrument OverviewExcellent protection from changes in ambient temperature and atmosphericpressure is achieved by sealing the Autograv sensing element in a temperaturestabilized vacuum chamber. The wide operating temperature of -40°Cto +45°C (optional +35°C or +55°C) enables the operator to use the Autogravin many environments. Since the sensor is made from non-magnetic fusedquartz, the Autograv is not affected by magnetic field variations (as long asthey are less than ten times the Earth’s magnetic field, i.e. ± 0.5mT).Low drift is a result of the extremely stable operating environment of thequartz elastic system. It allows the long term drift of the sensor to be accuratelypredicted and a real time software correction reduces it to less than0.02 mGals per day.Internal tilt sensors constantly supply the Autograv with information whenan operator selects the continuous tilt correction feature. If measurementsare taken on unstable ground, errors due to the movement of the Autogravare automatically eliminated.An automatic tidal correction can also be selected via the keyboard. The operatorenters in the geographical location and time zone information andthe Autograv automatically calculates and applies a real time tidal correctionto each reading.The internal 12 volt rechargeable battery provides sufficient power to operatethe Autograv throughout a normal survey day. An operator can check thebattery voltage at any time by pressing a key and viewing the display. Whenthe battery voltage is approaching the discharge level, the Autograv emits anaudible alarm. An optional cable enables the instrument to operate fromany external 12 volt DC power supply or battery which can supply 3 amperespeak current. In the event of a main battery failure, a set of built-in miniaturebatteries keeps the memory safe for several days.1-2 Autograv CG–3 Manual