Abstract: A hydrometer comprises a transparent container including a top opening, two arcuate dividers extended from both sides of top opening for dividing the interior of container into a measuring chamber and two opposite side channels each having a bottom open end in communication with measuring chamber and a top inlet open to outside, and a pointer pivotably mounted inside measuring chamber and adapted for indicating a specific gravity of liquid (e.g., sea water) contained in measuring chamber A fluid path is formed from top inlet through channel and bottom open end into measuring chamber as container immersed in the liquid to be measured. This can avoid the generation of bubbles. Further, the time(s) of adjustment of the specific gravity of liquid can be precisely determined.

Abstract: A method of improving an output characteristic of an angular rate sensor including, for example, a fork oscillator and an improved structure of an angular rate sensor are provided. The improvement of the output characteristic is achieved by adjusting a physical structure of the oscillator to minimize unwanted vibrations of the oscillator or noises of a sensor output. The adjustment of the physical structure is achieved by trimming away an edge portion of the oscillator or a supporter for supporting the oscillator on a base.