Fluid density measuring apparatus

A fluid density measuring apparatus is provided of the kind wherein a nozzle directs a turbulent jet through another fluid to a receiver tube, and is improved in that surfaces, from which sound waves emanating directly from the jet will be reflected, are outside the jet flow and are inclined at obtuse angles to these sound waves so that they will be reflected away from the jet. The fluid from the jet may be the one whose density is to be measured, in which case the density of the other fluid is known. The inclined surfaces minimize any effect the reflected sound waves may have on the spreading rate of the jet from the nozzle and thus improve the sensitivity of the apparatus.