Abstract: A fluid flow meter is disposed in a conduit. A casing of the flow meter includes a main body section defining a circuit board installation recess, and has a peripheral wall section projecting from the main body section so as to surround the circuit board installation recess. A part of the peripheral wall section is cut out to form an installation plate insertion groove. A silicon-containing filler is disposed in the board installation recess of the casing to cover the circuit board. A fluorine-containing sealant is disposed in the board installation recess close to the installation plate insertion groove so as to seal the installation plate insertion groove and maintain the silicon-containing filler inside the board installation recess.

Abstract: An fluid flow meter for measuring a flow amount of gas. The fluid flow meter comprising a casing installed to a conduit in which a measured gas flows. The casing includes a main body section defining a board installation recess, and a peripheral wall section projecting from the main body section and surrounding the board installation recess. A part of the peripheral wall section is cut out to form an installation plate insertion groove, the part abutting to an inside of the conduit. An installation plate is provided including a board installation section disposed in the board installation recess, and an element installation section extending from the board installation section through the installation plate insertion groove to an outside of the board installation recess. A circuit board is disposed on the board installation section of the installation plate, electronic parts being provided to the circuit board.

Abstract: An apparatus for measuring gas flow rate is comprised of a pipe body whose inside space performs as a passage for flowing measured gas. A housing including a generally U-shaped bypass passage is integrally formed with the pipe body. A plate-type flow-rate detection element is disposed in a first passage of the bypass passage, and a passage restricting portion is disposed in a second passage of the bypass passage downstream of the first passage. The inlet portion of the bypass passage is disposed in the vicinity of an axial center of the pipe body, and the outlet port of the bypass passage is disposed in the vicinity of a pipe wall of the pipe body. Therefore, the influence of a pulsating flow to the flow-rate detection element is decreased, and the high-accuracy detecting of gas flow-rate is executed.