Patent ID: 8504311
Filing Date: 2013-08-06
Classification: G01F,G05D,Y10T

Abstract:
1. A mass flow controller comprising: a bridge circuit including a first, second, third, and fourth nodes, a first resistive component being connected between the first and second nodes, a second resistive component being connected between the second and third nodes, a first sensing element being connected between the first and fourth nodes, a second sensing element being connected between the fourth and third nodes; a first processing portion to provide a first output that is indicative of a differential voltage between the second and fourth nodes; a second processing portion to provide a second output indicative of a top voltage between the first node and the third node; a look-up table that maps flow values of a calibration gas with calibration data, the calibration data being based upon values of the differential voltage and the top voltage that correspond to the flow values of the calibration gas; and a control portion configured to: