| 摘要 |
<p>A densimeter for measuring the density of liquids is disclosed. The densimeter comprises a substantially vertical shaft having a central axis. The densimeter further comprises a motor for rotating the shaft about its axis and a vessel mounted on the shaft asymmetrically with respect to the shaft axis. A counterbalance is provided on the shaft for at least partly compensating for the asymmetry. The shaft is resiliently mounted with freedom of oscillation transverse to the shaft axis. A measuring device is provided for measuring the amplitude of the oscillations, this being proportional of the deviation of the specific gravity of the sample from a reference value. The measuring device comprises a slotted drum carried by the shaft and acting to shutter two light beams as the shaft rotates. Two waveforms are generated and a device measures the phase shift between the waveforms, this being indicative of the amplitude of the oscillations. Instead of a discrete sample, a continuous flow of liquid may be measured, the liquid passing to the vessel through one of two concentric tubes forming the shaft and the liquid returning from the vesel via the space between the two tubes.</p> |
