This paper explores the concept and the levels of genericity of different instruments, or beamlines, at a synchrotron radiation facility. We use conceptual tools from the sociology of science, bibliometrics and data from the European Synchrotron Radiation Facility (ESRF) publication database, enriched by data from Web of Science. The sample size is of 11,218 observations for the period 1996 to 2018. The combined data set includes the beamline name, available from the ESRF library database, which makes the instrument-level analysis possible. We operationalize instrument genericity as the disciplinary diversity in the corpus related to each instrument with a Herfindahl-based index theoretically supported by the concept of generic instruments. As a result, we gain a quantitative insight into the generic character of the instruments, as well as the way in which different scientific fields and the experimental use of instruments group and align.