Applications: Current primary application for the G-856AX is as a base station system for monitoring and recording of the earth's diurnal field shift.  This base data is downloaded into MagMap2000 for automatic correction of G-865AX, G-858 or airborne survey data.  A standard accessory package with external power and 50 ft. sensor cable is available for base station operations. The G-856AX is also used in mapping geological structures, for mineral exploration, magnetic search for industrial, environmental or archaeological targets.  The optional gradiometer attachment gives greater resolution and noise immunity for conducting searches in industrial or high cultural noise environments. Simple operation, large digital data storage capability, and the inclusion of MagMap2000 data transfer and editing software provides a system well suited for both teaching and survey applications.   A thoroughly well proven design (over 2,500 units sold), excellent performance and the lowest price professional system are key features of the G-856AX. Combined with the ease of use, user friendly download/editing software, and readily available commercial contouring programs, the G-856AX represents a complete magnetic surveying package generating high quality data for budget conscious users. Specifications: Resolution: 0.1 nT Accuracy : 0.5 nT Clock: Julian date, accuracy 5 sec per month. Tuning: Auto or manual, range 20,000 to 90,000 nT Gradient Tolerance: 1000 nT/meter Cycle time:3 sec to 999 sec standard , can be manually selected as fast as 1.5 sec cycle time. Read: Manual, or auto cycle for base station use. Memory: 5700 field or 12500 base station readings Display: Six digit display of field/time, three digit auxiliary display of line number, day Digital Output: RS-232,  9600 baud. Input: Will accept external cycle command. Physical: Console: 7 x 10.5 x 3.5 inches, (18 x 27 x 9 cm) 6 lbs (2.7 kg) Sensor: 3.5 x 5 inches ( 9 x 13 cm) 4 lbs (1.8 kg Environmental:   Meets specifications within 0 to 40 C Will operate satisfactorily from -20 to 50 C Power: 9 each  1.5 "D" Cells Standard Accessories: Sensor, Staff, Chest Harness, Two sets of batteries, RS-232 cable, Operations manual,  Applications manual, MagMap 96 software Options: Gradiometer attachment. External Power/sensor lead, External power/RS-232/sensor lead, rechargeable battery and charger set