Limit switch for identifying whether a measured material arranged within a hollow body undershoots or exceeds a minimum or maximum limit level, wherein the limit switch comprises: - a detector device, wherein the detector device is designed to record radiometric radiation of at least the measured material in an at least partly penetrating manner at at least two different points (Pzl, Pz2) along a direction of change (z) of a fill level of the measured material, and - an evaluation device, wherein the evaluation device is designed - to identify a change in a radiometric radiation recorded by the detector device at at least the two points (Pz1, Pz2), - to determine a change period (Δt) or a variable corresponding to the change period (Δt) for the identified change, and, - if the determined change period (Δt) or the variable satisfies a change criterion, wherein the change criterion is characteristic of the fact that the change period (Δt) is equal to or greater than a time threshold value (ΔtG), to determine the undershooting or exceeding, - wherein the detector device comprises a first detector, in particular a first point detector, characterized in that the detector device comprises a second detector, in particular a second point detector, different from the first detector, wherein the first detector is designed to record the radiation at a first point of the two points (Pz1, Pz2), and wherein the second detector is designed to record the radiation at a second point of the two points, different from the first point, and in that the evaluation device is designed to identify the change based on the radiation recorded by the first detector at the first point and the radiation recorded by the second detector at the second point. - a detector device, wherein the detector device is designed to record radiometric radiation of at least the measured material in an at least partly penetrating manner at at least two different points (Pzl, Pz2) along a direction of change (z) of a fill level of the measured material, and - an evaluation device, wherein the evaluation device is designed - to identify a change in a radiometric radiation recorded by the detector device at at least the two points (Pz1, Pz2), - to determine a change period (Δt) or a variable corresponding to the change period (Δt) for the identified change, and, - if the determined change period (Δt) or the variable satisfies a change criterion, wherein the change criterion is characteristic of the fact that the change period (Δt) is equal to or greater than a time threshold value (ΔtG), to determine the undershooting or exceeding, - wherein the detector device comprises a first detector, in particular a first point detector, characterized in that the detector device comprises a second detector, in particular a second point detector, different from the first detector, wherein the first detector is designed to record the radiation at a first point of the two points (Pz1, Pz2), and wherein the second detector is designed to record the radiation at a second point of the two points, different from the first point, and in that the evaluation device is designed to identify the change based on the radiation recorded by the first detector at the first point and the radiation recorded by the second detector at the second point.