Ramón Jardí i Borrás falling. If the rain is heavy enough, it can exceed the device's capacity. At that level, the regulating hole is uncovered, discarding the excess water. If the rain decreases, the buoy drops at the same speed -as the cylindrical reservoir empties. The pluviometer recorded precipitation in Barcelona for 95 years and in places such as Hong-Kong). To measure the average intensity of rainfall in a certain interval of time, the Pluviometer of intensities uses the formula: Intensity varies over time. The pluviometer records instantaneous rain intensity (as its name defines): Ramón Jardí i Borrás Ramon Jardí i Borras (Tivissa, November
Pre-measure is called "σ"-additivity. Thus, what is missing for a pre-measure to be a measure is that it is not necessarily defined on a sigma-algebra (or a sigma-ring). It turns out that pre-measures give rise quite naturally to outer measures, which are defined for all subsets of the space "X". More precisely, if "μ" is a pre-measure defined on a ring of subsets "R" of the space "X", then the set function "μ" defined by is an outer measure on "X" and the measure "μ" induced by "μ" on the σ-algebra Σ of Carathéodory-measurable sets satisfies formula_4 for formula_5 (in particular,