Piezoelectric sensor

Abstract

A piezoelectric sensor capable of preventing fluctuation in the sensitivity of the piezoelectric sensor over a wide temperature range is provided. This is a piezoelectric sensor comprising a piezoelectric element and a holding member for holding the piezoelectric element, the piezoelectric element comprising a piezoelectric ceramic having formed on the surfaces thereof a pair of electrodes. The piezoelectric ceramic satisfies the following requirement (a) and/or requirement (b): (a) in the temperature range from −30° C. to 160° C., the thermal expansion coefficient is 3.0 ppm/° C. or more, and (b) in the temperature range from −30° C. to 160° C., the pyroelectric coefficient is 400 μCm−2K−1 or less.

Dependencies are inferred from the claim text.