Abstrait

Constant airflow sensing of vehicle intake system based-on hot-film airflow sensor

Rong-Hua Ma

The goal of this study is to develop an airflow meter sensor for vehicle intake system detection in internal combustion engines. The study uses micro-electromechanical process technology to develop a hot-filmflowmeter with an alumina substrate and platinum film heater; the hotline method is used to create a micro airflow anemometry meter sensor relying on variations in resistance of the platinum film corresponding to different wind velocity at the set temperatures. The micro-sensor is less bulky and simpler structure than ordinary meters, and its small size enables it to provide good sensitivity and measurement precision. The alumina plate used in this study is produced by polishing an alumina substrate, a platinum film is then deposited on the plate to complete the micro-heater used in the sensor. Resistance on the sensor side varies as gas flows through the sensor, and the instrument determines airflow velocity on the basis of the changes in resistance caused by gas flow differences.Airflow velocity form10m/s to 60m/s are used to test. It seems a regular slope resistance varies, indicating the relationship between airflow velocities varies remain predictable throughout the sensing range. Therefore, the sensor can achieve its airflow measurement purpose completely.