Patent ID: 6956382
Filing Date: 2005-10-18
Classification: G01F

Abstract:
1. A radar level gauge coupleable to a two-wire process control loop for measuring level of a product in a tank comprising: a microwave antenna unit directable into a tank, a low power microwave source for sending a microwave signal through the antenna unit into the tank, a low power microwave receiver for receiving a reflected microwave signal from a surface of the product in the tank, measurement circuitry coupled to the source and receiver for initiating transmission of the microwave signal and for determining product level based upon the received signal, output circuitry coupled to the two-wire process control loop for transmitting information related to product level over the loop, power supply circuitry coupled to the two-wire process control loop for receiving power from the loop being the sole source of power for the low power microwave source, the low power microwave receiver, the measurement circuitry and the output circuitry in the radar level gauge, an isolation circuit for non-conductively transferring power from the loop to the power supply circuitry and for the non-conductively transmitting said information between the output circuitry and said loop and said transferring of power from the loop to the power supply circuit performed by means of an inductive coupling device.