A professional who records readings of gravity meter, torsion balance, and other gravity-measuring instruments at various points in terrain to obtain data regarding gravity characteristics indicating potential source of metallic ore or petroleum deposits. Responsibilities include:

• Sets up or directs set-up of instruments at specified location and records readings.
• Examines readings for accurate registration and adjusts instruments to specifications.
• Reads thermometers, barometers, and other instruments and records variations in temperature, barometric pressure, elevation, and other physical factors that affect instrument readings.
• May be designated according to instrument used as Gravity-Meter Observer; Magnetometer Operator.