초록 ▼

An arrangement for fill level measurement is provided, with which accurate fill level measurement on a continuing basis is possible, including a container (3) containing a fill substance (1) whose fill level is to be measured, a fill level measuring device ( 5) arranged at the container (3) and oper

An arrangement for fill level measurement is provided, with which accurate fill level measurement on a continuing basis is possible, including a container (3) containing a fill substance (1) whose fill level is to be measured, a fill level measuring device ( 5) arranged at the container (3) and operating according to the travel time principle, an apparatus (11, 13) for registering a filling and/or emptying of the container (3), an auxiliary unit (19), which by means of the filling and/or emptying registered by the apparatus (11, 13), determines an instantaneous change in fill level (VL) or an instantaneous change in material flow rate, and makes such available to the fill level measuring device (5) for determining the fill level (L) to be measured.

대표청구항 ▼

The invention claimed is: 1. A method for fill level measurement with an arrangement for fill level measurement having a fill level measuring device arranged on the container, and operating according to the travel time principle, a material flow apparatus for registering or recording a filling and/

The invention claimed is: 1. A method for fill level measurement with an arrangement for fill level measurement having a fill level measuring device arranged on the container, and operating according to the travel time principle, a material flow apparatus for registering or recording a filling and/or emptying of the container, and an auxiliary unit, which by means of the filling and/or emptying registered or recorded by said material flow apparatus determines the instantaneous change in fill level (VL) or the instantaneous material flow rate, the method comprising the steps of: transmitting a send-signal (S) to the fill substance; receiving the echo-signal (E) of the send-signal; determining at least one echo (E) of the echo-signal (E); determining a provisional fill level (LE) from the travel time (tE) of this, respectively these, echoes (E); determining a measured change (V(E)) in the fill level from the provisional fill level (LE) and at least one other fill level (L) measured in a previous measuring cycle; determining a deviation (Δ(V(E); VL) between the measured change in fill level (V(E)) and the instantaneous change in fill level (VL); determining at least one other echo (E') as probably the echo (E') reflected on the upper surface of the fill substance when the deviation (Δ(V(E); VL) exceeds a predetermined upper limit (ΔM); and repeating said last determination until an echo (E) is found for which the deviation (Δ(V(E); VL) lies below the predetermined upper limit (ΔM), and the provisional fill level (LE) corresponding to this echo (E) is then accepted as the measured fill level (L), or until a terminating condition (X) occurs. 2. The method as claimed in claim 1, wherein: for the case that a terminating condition (X) occurs, one of the following results: a safety mode (43) is assumed, and in the case of a known instantaneous change in fill level (VL), the fill level to be measured is extrapolated from the previously measured fill level (L) and the instantaneous change in fill level (VL), and in the case of an unknown instantaneous change in fill level (V L), the fill level to be measured is set equal to the previously measured fill level (L). 3. The method as claimed in claim 1, wherein: in each measuring cycle the echo probably reflected on the upper surface of the fill level is sought within a window, and the position of the window is given by the travel time corresponding to the previously measured fill level (L). 4. The method as claimed in claim 3, wherein: for the case that no echo (E) leading to a measured fill level (L) can be found within the window, in the case of a known instantaneous change in fill level (VL), the fill level to be measured is extrapolated from the previously measured fill level (L) and the instantaneous change in fill level (VL), and in the case of an unknown instantaneous change in fill level (VL), the fill level to be measured is set equal to the previously measured fill level (L). 5. The method as claimed in claim 4, wherein: the window has one of the following: a predetermined breadth when the previously determined fill level (L) was found using an echo, a breadth enlarged by a factor allowing for increased uncertainty when the previously determined fill level (L) was found using extrapolation, and a size at which the fill level to be measured in the next measuring cycle will then also still lie in the window, when the fill level changes at a maximum velocity predetermined by the arrangement, if the fill level to be measured previously was set equal to the preceding current fill level.