A Carrier Gas Flow Velocity and Flow Direction Sensor and its Interface Circuit

Abstract

For the selenium content on-line detection of low voltage electrophoresis chip-atomic fluorescence, a design scheme of carrier gas flow velocity and flow direction sensor, which is fabricated using MEMS technology, is presented. A new structure was designed to achieve the current detection of heater, the detection of temperature and the discrimination of flow direction. Cu layer of the flexible PCB was used as resistive material because of its stable physical properties and linearity of temperature to resistance conversion. The sensor consists of one copper current detector, two copper flow direction detectors, one double-spiral copper micro-heater and one copper temperature detector. The operating principles and the fabrication of carrier gas flow velocity and flow direction sensor is emphatically expounded. Simultaneously, the detection and control system of carrier gas flow velocity and flow direction sensor and its interface circuit are analyzed and discussed.