Patent ID: 6198424
Filing Date: 2001-03-06
Classification: G01F,G01S

Abstract:
A low power radar level transmitter providing multiple process product interface detection, the level transmitter comprising:a termination positionable into first and second products in a tank;a pulse generator coupled to the termination to generate a microwave transmit pulse which is transmitted along the termination into the first and second products in the tank, a first portion of the transmit pulse being reflected at a first product interface and a second portion of the transmit pulse being reflected at a second product interface, the second product interface being formed between the first and second products;a pulse receiver coupled to the termination to receive a first reflected wave pulse corresponding to reflection of the first portion of the transmit pulse at the first product interface, and to receive a second reflected wave pulse corresponding to reflection of the second portion of the transmit pulse at the second product interface;a threshold controller coupled to the pulse receiver to detect whether the first reflected wave pulse at least meets a first threshold value and whether the second reflected wave pulse at least meets a second threshold value, and provide receive pulse output information related to detection of the first and second reflected wave pulses;a dielectric constant calculator coupled to the threshold controller to calculate a dielectric constant of the first product in the tank as a function of the receive pulse output information; anda level computer coupled to the threshold controller and to the dielectric constant calculator to calculate a level of the first product as a function of a time of detection of the first reflected wave pulse, and to calculate a level of the second product as a function of a time of detection of the second reflected wave pulse and as a function of the calculated dielectric constant of the first product.