CET. A cased hole cement evaluation log that displays data processed from ultrasonic transducers in such a way that channels in the cement sheath can be detected. The quality of the cement is given in eight radial segments, and the orientation of a channel can be determined from a recording of the well deviation and the relative bearing of the first transducer. An acoustic caliper measurement is provided from eight radii measurements. Compare cement bond log. CET is a Schlumberger mark.