Patent attributes
The invention is a method to detect a weak interface signal in a guided wave level measurement device. The device includes a waveguide, a signal generator and a signal receiver, the signal generator and signal receiver being operationally connected to the waveguide. The method includes the steps of transmitting an outgoing signal; monitoring the signal received at the signal receiver to detect a first signal level that exceeds or equals a first threshold level (TH1) and if such a signal level is detected, continue monitoring the received signal to detect a second signal level that exceeds or equals TH1. Finally, if a second signal level in excess of TH1 is detected, continue monitoring the received signal to detect a third signal level that exceeds or equals a second threshold level TH2.