Abstract: A vortex type flowmeter having a body member, a cover member and an interior varying diameter cavity formed in the body member in which fluid is introduced to flow in a generally helical pattern within the cavity, the fluid being introduced at the periphery of the cavity having the largest diameter and the fluid exiting from an aperture at the center of the vortex formed by the helical flow. The flowmeter includes a toothed rotor mounted for rotation within the cavity and the flow of fluid causes the rotor to rotate within the cavity at a rotational rate which is generally directly related to the velocity of flow. The flowmeter is provided with a light-emitting diode and photosensitive transistor combination which senses the passage of each of the teeth as the rotor is rotating within the cavity. This combination is formed as a unitary assembly, a portion of which nests a portion of the rotor.

Abstract: A vortex type flowmeter having a body member, a cover member and an interior varying diameter cavity formed in the body member in which fluid is introduced to flow in a generally helical pattern within the cavity, the fluid being introduced at the periphery of the cavity having the largest diameter and the fluid exiting from an aperture at the center of the vortex formed by the helical flow. The flowmeter includes a toothed rotor mounted for rotation within the cavity and the flow of fluid causes the rotor to rotate within the cavity at a rotational rate which is generally directly related to the velocity of flow. The flowmeter is provided with a light-emitting diode and photosensitive transistor combination which senses the passage of each of the teeth as the rotor is rotating within the cavity.