This paper reconstructs the theoretical rationale and technical implementation of a logarithmic scale paradigm for pitch analysis devised by Chinese phonetician Fu Liu (刘复) in the 1920s. Faced with the challenge of representing tones, which requires both fine-grained measurement and the visualization of psychoacoustically motivated pitch contours, Liu designed a system based on logarithmic spacing and twelve-tone equal temperament. Unlike his European and American contemporaries such as Daniel Jones, Rousselot, and Scripture, who relied on perceptual judgment, proportional Musical scales, or direct frequency tracing, Liu sought a reproducible framework for tonal analysis grounded in numerical precision. Drawing on original documents and comparative analysis, this study situates Liu’s work within the broader context of early 20th-century phonetics. The logarithmic scale is now widely used in modern acoustic analysis tools, but Liu’s accurate implementation of the scale was achieved manually before our digital era, which should be considered as a pioneering contribution. Through the lens of Liu’s legacy — often overlooked — we show the importance of cross-cultural and crossdisciplinary exchange in shaping the early development of phonetic sciences.