In the theoretical approach that bypasses gravity entirely, how is mass determined using an inertial balance?

Answer

By measuring the resulting frequency of oscillation when the object is attached to a spring

Inertial mass is found by attaching the object to a spring and measuring the period of vibration or resulting oscillation frequency, allowing calculation based on resistance to acceleration ($m=F/a$).

In the theoretical approach that bypasses gravity entirely, how is mass determined using an inertial balance?
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