Sensitive Measurement of Flow Velocity and Flow Direction Using a Circular Thermistor Array
نویسندگان
چکیده
Eight highly sensitive amorphous germanium thermistors (TCR = -1.8%/K) are the sensitive part of the micromachined sensors for flow velocity and flow direction. Carried by a 1.3 μm thick diaphragm they measure temperature differences generated by the sample flow and a heater (430 μW). This allows gas flow measurements in the range from 0.025 m/s to about 3 m/s with a sensitivity of up to 30 mV/(m/s). Two orthogonal pairs of opposed thermistors feature a sensitivity of 150 μV/°. An increase in sensitivity (50%) is gained by using two 90° rotated thermistors situated in the downstream position.
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