Split-flow-type flow sensor device

摘要

A split-flow-type flow sensor apparatus includes a main flow passage and a bypass flow passage, wherein a thermal flow sensor is placed on the wall face of the bypass flow passage. A first rectification member is placed upstream from a diversion part to the bypass flow passage in the main flow passage, and a second rectification member is placed upstream from the thermal flow sensor in the bypass flow passage. A bypass flow passage module is inserted into an opening formed on a side of a main flow passage module. The side opening of the main flow passage module is sealed and an entrance and an exit of the bypass flow passage are positioned in the main flow passage.