The invention relates to a weight measuring apparatus utilizing a vibration type force sensor having a greatly increased Q and being inexpensive and easy to manufacture. The force sensor includes a single vibratory beam or a pair of vibratory beams, which oscillate at a particular measurement frequency related to the stress applied to the sensor by a weight. A rotational mass is coupled to a nodal point of the vibratory beam at the measurement frequency, and greatly influence the frequency at which the beam will vibrate. As a result, the tolerances for manufacture of the force sensor are greatly relaxed, and the pendulum-like movement of the rotational masses for a double-ended tuning fork type sensor tends to override any mismatch between the two parallel vibratory beams.