Abstract: Hitherto known gratings for covering shafts, channels or similar structures comprise peripheral rails (10, 10?) cross-bars (20) that are joined to the peripheral rails (10, 10?) and consist of sheet metal sections, and longitudinal bars (30) joined to the cross-bars (20). In order to provide a better foothold and improved anti-skid properties, the longitudinal bars (30) are secured to the cross-bars (20) in such a way that top stepping surfaces (31) of the longitudinal bars (30) are lower than or flush with at least stepping portions (21) of upper edges (22) of the cross-bars (20).

Abstract: In a method for determining a frequency/time profile of hit sequences and the corresponding device, a measuring window is opened after an external starting signal has been locked. As long as the measuring window is open, the clock periods are counted. If a hit occurs, it is marked with the number of clock periods elapsed up until it occurs, the so-called time mark. The number of hits with this specific time mark determined hitherto is implemented by one. Repeated opening of the measuring window results in a frequency/time profile of the hit sequences due to the fact that, for each value of the time mark, the number of correspondingly marked hits is added together. The hit detection, the hit analysis and the final hit processing all occur in real time for each individual hit in a single measuring step, i.e. the processing of a hit sequence is already concluded immediately after a measuring cycle has elapsed.