A novel approach for a high precision multi target level measurement system based on time-domain-reflectometry

A novel approach for a high precision multi target TDR level measurement system is presented with a greatly improved performance, to fulfil the growing needs of today´s industrial level measurement applications. Starting with the well known concept of the time-domain-reflectometry (TDR), a novel concept for the frequency stabilisation and the pulse generation lead to a higher performance compared to conventional industrial systems with regard to their precision, their resolution and their dynamic range. This article focuses on the description of the improved signal generation unit, comprising the generation of two RF-signals with a small frequency offset and a good phase noise performance and the generation of short electromagnetic pulses, optimized for the detection of thin interface layers. To determine the stability, the resolution and the dynamic range of the improved TDR-system, a prototype system is set up.