Abstract: A servo type accelerometer including a main support base, a pendulum assembly and a servo arrangement is disclosed herein. The pendulum assembly includes a pendulum and means supporting the pendulum for limited rotational movement through a normal resting plane about a fixed axis within that plane and relative to the base in response to and as a result of the pendulum being subjected to acceleration forces normal to the resting plane. The servo arrangement cooperates with the pendulum for monitoring the presence and magnitude of these acceleration forces, if present. A particular feature of the accelerometer disclosed resides in specifically designed flexures for supporting the pendulum and a technique for preventing these flexures from being placed in a state of compression and possibly being damaged thereby.

Abstract: An angular rate instrument adapted for mounting to a given object for measuring the rate of turn of the latter is disclosed herein. This instrument utilizes an angular accelerometer to sense angular acceleration to which the instrument is subjected and a circuit for integrating the difference between this signal and a reference signal to produce an integrated output signal corresponding to the rate of turn of the object. The angular rate instrument also utilizes a null circuit for producing the reference signal in response to and dependent on low frequency error signals which appear at the output of the signal integrating circuit. The null circuit uses a capacitor to provide the reference signal and means for maintaining the charge on the capacitor during power interruptions so as to prevent losing the reference signal as a result of such interruptions.