Limit switch (G) for identifying whether a measured material (S) arranged within a hollow body (B) undershoots or exceeds a minimum or maximum limit level (z0), wherein the limit switch (G) comprises: - a detector device (D), wherein the detector device (D) is designed to record radiometric radiation (RS) of at least the measured material (S) 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 (FS) of the measured material (S), and - an evaluation device (A), wherein the evaluation device (A) is designed - to identify a change in a radiometric radiation (RS) recorded by the detector device (D) at at least the two points (Pz1, Pz2), - to determine a change period (Δt) or a variable (GR) corresponding to the change period (Δt) for the identified change, and, - if the determined change period (Δt) or the variable (GR) satisfies a change criterion (AK), wherein the change criterion (AK) 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 (D) comprises a first detector (D1), in particular a first point detector (PD1), characterized in that the detector device (D) comprises a second detector (D2), in particular a second point detector (PD2), different from the first detector (D1), wherein the first detector (D1) is designed to record the radiation (RS) at a first point (Pz1) of the two points (Pz1, Pz2), and wherein the second detector (D2) is designed to record the radiation (RS) at a second point (Pz2) of the two points, different from the first point (Pz1), and in that the evaluation device (A) is designed to identify the change based on the radiation (RS) recorded by the first detector (D1) at the first point (Pz1) and the radiation (RS) recorded by the second detector (D2) at the second point (Pz2). - a detector device (D), wherein the detector device (D) is designed to record radiometric radiation (RS) of at least the measured material (S) 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 (FS) of the measured material (S), and - an evaluation device (A), wherein the evaluation device (A) is designed - to identify a change in a radiometric radiation (RS) recorded by the detector device (D) at at least the two points (Pz1, Pz2), - to determine a change period (Δt) or a variable (GR) corresponding to the change period (Δt) for the identified change, and, - if the determined change period (Δt) or the variable (GR) satisfies a change criterion (AK), wherein the change criterion (AK) 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 (D) comprises a first detector (D1), in particular a first point detector (PD1), characterized in that the detector device (D) comprises a second detector (D2), in particular a second point detector (PD2), different from the first detector (D1), wherein the first detector (D1) is designed to record the radiation (RS) at a first point (Pz1) of the two points (Pz1, Pz2), and wherein the second detector (D2) is designed to record the radiation (RS) at a second point (Pz2) of the two points, different from the first point (Pz1), and in that the evaluation device (A) is designed to identify the change based on the radiation (RS) recorded by the first detector (D1) at the first point (Pz1) and the radiation (RS) recorded by the second detector (D2) at the second point (Pz2). <EOS>