一前言物理科学是最讲究精确的,为了描述各种量的大小,就给这些量定义一些单位。有一门专门研究科学上各种单位的学科,叫做计量学。实际上,地震学上通用的震级单位“级”,也是一个计量学的问题。计量学所定义的单位,一般应服从三条基本原则:第一,所建立的单位是合理的;第二,单位的复现精确度要高;第三,使用应当简便迅速。我们用“合理、精确、实用”六个 I. INTRODUCTION Physical science is the most precise and precise, and to describe the size of various quantities, some units are defined for these quantities. There is a discipline specializing in various units of science called metrology. In fact, the seismically universal magnitude unit “level” is also a metrological problem. The units defined by metrology generally should be subject to three basic principles: first, the units established are reasonable; second, the unit’s recurring accuracy is high; and third, the use should be quick and easy. We use “reasonable, precise and practical” six