A pulsed supersonic molecular beam apparatus has been constructed using an automobile fuel injector as the nozzle beam source and a “flow-through” detector. The apparatus is separated into three parts and is differentially evacuated by five turbo-molecular pumps with moderate pumping speeds. The flow-through detector, which has a high senistivity and a sufficient time resolution, was used in time-of-flight (TOF) measurements of molecular velocities. For the TOF measurements of the pulsed beams we developed a data acquisition system using two personal computers. The maximum speed ratios and absolute beam intensities of the pulsed beams of He, Ne, Ar, D2, N2, CO2 and C2H2 prepared in the present apparatus are satisfactorily high compared with the values so far published.
The movable orifice flowmeter, here reported, is an orifice meter of force measuring type. An orifice plate in a pipe is supported by a bellows or springs and can be displaced slightly along the axis of the pipe. The flow rate can be obtained from the measurement of the force F exerted on the orifice plate by the bellows or springs. For a steady flow of liquid of density ρ, the flow rate Q is expressed by Q=αK√-F/ρ where K is a constant of the apparatus used and α is the flow coefficient. The above equation is obtained from Newton's law of motion and Bernoulli's theorem. Eight trial flowmeters of three different types have been experimentally examined. The results of these experiments show that flow rates can be obtained by a calibrated movable orifice flowmeter.