Abstract: A gas turbine meter that is miniaturized based on its design is disclosed. While the size of the gas turbine meter is small, it performs all the functions of prior gas turbine meters and has a large rangeability over a very large range of pressure. The turbine meter includes a body which is bilateral or symmetrical, permitting the turbine meter to be installed in either orientation in a flow line. Diffusers are included with the turbine meter that maintain the rotor of the turbine meter in position and prevent dust from entering into bearings which connect the rotor with the diffusers. The rotor of the turbine meter optimally has twelve flat vanes, each having blades angled at 45.degree. from the plane of the blank in which it was made. Close clearance is maintained between the blades and the interior of the meter. Slots are formed at the lower end of the rotor, thereby forming the shanks of the vanes. The slots are optimally sized to increase stiffness.

Abstract: A method and apparatus for transporting solid particulate material and calculating mass flow rate of the material through a rotary feeder having helical pockets is provided. At least one radiation source and two or more detectors are positioned in a manner whereby radiation flux is directed through, and attenuated by particulate material contained in a helical pocket. The amount of attenuation is measured at least when the pocket is filled with material and when the pocket has discharged most of the material. The difference in the amount of flux detected at the filled and discharged positions is used to determine the mass flow rate of the particulate material.