Patent ID: 6786102
Filing Date: 2004-09-07
Classification: G01N,G01P,G06F

Abstract:
A process for calculating an automatically calibrated gas velocity vector in external pressure-temperature, the process comprising:providing first and second transmitters adapted to transmit ultrasonic pulses, wherein the first transmitter is in an open configuration and the second transmitter is in a first ventilated tube, such chat the second transmitter is positioned along a first axis; providing third and fourth transmitters adapted to transmit ultrasonic pulses, wherein the third transmitter is in an open configuration and the fourth transmitter is in a second ventilated tube, such that the fourth transmitter is positioned along a second axis, the second axis perpendicular to the first axis; providing a receiver adapted to receive ultrasonic pulses from the transmitters, whereby the first and second transmitters are each positioned a first distance from the receiver, the third and fourth transmitters are each positioned a second distance from the receiver and are each positioned at a 90 degree angle from the first and second transmitters; transmitting a first ultrasonic pulse from the first transmitter to the receiver; calculating a first transit time vector for the first pulse to reach the receiver; transmitting a second ultrasonic pulse from the second transmitter to the receiver; calculating a second transit time vector for the second pulse to reach the receiver; transmitting a third ultrasonic pulse from the third transmitter to the receiver; calculating a third transit time vector for the third pulse to reach the receiver; transmitting a fourth ultrasonic pulse from the fourth transmitter to the receiver; calculating a fourth transit time vector for the fourth pulse to reach the receiver; calculating a first transit time differential vector by taking a first difference between the calculated first transit time vector and a first predetermined time transit vector; calculating a second transit time differential vector by taking a second difference between the calculated second transit time vector and a second predetermined time transit vector; calculating a third transit time differential vector by taking a third difference between the calculated third transit time vector and a third predetermined time transit vector; calculating a fourth transit time differential vector by taking a fourth difference between the calculated fourth transit time vector and a fourth predetermined time transit vector; calculating a first automatically calibrated gas velocity component vector by taking a first differential difference between the calculated first and second transit time differential vectors; calculating a second automatically calibrated gas velocity component vector by taking a second differential difference between the calculated third and fourth transit time differential vectors; and determining the automatically calibrated gas velocity vector by combining the first automatically calibrated gas velocity component vector and the second automatically calibrated gas velocity component vector.