Programmable gain control for rotating transducer ultrasonic tools

Abstract

A rotary ultrasonic transducer logging tool is set forth which has a transmitter connected to a transducer for transmitting pulses periodically, and a rotor with angle sensor connected thereto. One full revolution is divided into a specified number of incremental steps. The output of the receiver is supplied to an automatic gain control amplifier, then to an analog to digital converter. A gain control setting for the AGC amp is included. The AGC setting for the particular corresponding points in a first revolution of the transducer are used to provide settings for the AGC amplifier in the next revolution. A first buffer is used to store the data for the first revolution, a second buffer for the second revolution, and alternately back to the first buffer. These two buffers provide an output signal for a gain control buffer then input to the AGC amplifier. Alternate forms of gain control signal selection are used such as prior gain control settings.

Dependencies are inferred from the claim text.