A highly sensitive gravimeter using a magnetic parallel dipole line (PDL) trap system is provided. In one aspect, a gravimeter includes: a vacuum enclosure; a PDL trap within the vacuum enclosure, the PDL trap having a pair of dipole line magnets, and a diamagnetic rod levitating in between the dipole line magnets; and a heater and temperature sensor within the vacuum enclosure configured to maintain a constant temperature within the vacuum enclosure that is greater than a temperature outside of the vacuum enclosure and precision frequency measurement system. The frequency of the oscillation of the trapped diamagnetic rod will yield the local gravitational acceleration. Methods for measuring a local gravitational field using the present gravimeter are also provided.