1949年，压电晶体标准[l]发布，涵盖了压电晶体轴的定义及其与矩形轴的关系、规定晶体板方向的标准以及涉及压电关系、符号和单位的术语。1957年，关于压电晶体[2]的IRE标准发布，涵盖压电振子:定义和测量。本标准的目的是规定一种测定晶体基本弹性、压电和介电常数的方法。

IN 1949, Standards on Piezoelectric Crystals [ l ] were issued covering the definition of axes for piezoelectric crystals and their relation to rectangular axes, standards for specifying crystal plate orientation and nomenclature referring to the piezoelectric relations, symbols, and units. In 1957, the IRE Standards on Piezoelectric Crystals [2 ] was issued covering the piezoelectric vibrator: definition and measurements. It is the object of these present Standards to specify a method for determining the basic elastic, piezoelectric, and dielectric constants of crystals.