A micro channel integrated gas flow sensor for high sensitivity

In order to enhance measurement accuracy, a gas mass flow sensor integrated with micro channels is proposed in this paper. The uniqueness of this flow sensor is that there is thermal convection effect on two sides of diaphragm, which results in a more sensitive temperature distribution. The temperature characteristics of the novel flow sensor are simulated at different flow rates, and the optimization positions of the test resistor pair on the membrane are obtained from the simulations. Compared with traditional flow sensors, this flow sensor has higher measurement precision. When the incoming flow velocity is 3 m/s, its temperature difference between the upstream and the downstream can reach about 38.6 K, which is much higher than 26.8 K for the traditional flow sensor. In addition, the effects of physical parameters such as heater temperature and heater width are investigated. The results illustrate that the measurement accuracy increases but the measurement range narrows with increase of the heater temperature. The measurement accuracy increases and the measurement range widens with increase of the heater width.