This article addresses the problem of the impact of a major change in the "instrumentation space" of a given scientific domain. The domain under scrutiny is turbulent combustion. It has the peculcarcty of being developed, essentially since the 1940s, by the progressive interpenetration of two autonomous fields, the chemistry of combustion and the mechanics of turbulence. The analyzed change in instrumentation is a major one in that the new laser-based optical diagnostic techniques which, since the 1970s, invaded turbulent combustcon, allowed (...) for the first time the quantitative characterization of turbulent reacting flows. The impact of this new instrumentation on the relations between experimental and theoretical lines of work is analyzed. These relations concern both the global organization of the workplace and the scientific "division of labor" between theoreticians and experimentalists. The impact of the sudden availability of new experimental information on the cognitive structure of this borderland domain is also explored. (shrink)