Theoretical responses of a contact-break accelerometer are analyzed for steady-state and some transient motions. The distributed mass of the spring is considered in the present analysis. For steady-state motions, viscous damping is assumed to exist between the spring and the case of the instrument. Responses to simple harmonic motions of different frequencies are shown. Responses to a single cosine wave and a step function of acceleration are analyzed. The main source of error in the contact-break accelerometer is shown to be due to the spring mass. An electromagnetic-contact accelerometer with no spring mass is proposed. Preliminary study of this accelerometer is shown.