Tachometer

3 definitions found

From The Collaborative International Dictionary of English v.0.48 [gcide]:

  Hydrometer \Hy*drom"e*ter\, n. [Hydro-, 1 + -meter: cf. F.
     hydrom[`e]tre.]
     1. (Physics) An instrument for determining the specific
        gravities of liquids, and thence the strength spirituous
        liquors, saline solutions, etc.
        [1913 Webster]


  
     Note: It is usually made of glass with a graduated stem, and
           indicates the specific gravity of a liquid by the depth
           to which it sinks in it, the zero of the scale marking
           the depth to which it sinks in pure water. Extra
           weights are sometimes used to adapt the scale to
           liquids of different densities.
           [1913 Webster]
  
     2. An instrument, variously constructed, used for measuring
        the velocity or discharge of water, as in rivers, from
        reservoirs, etc., and called by various specific names
        according to its construction or use, as {tachometer},
        {rheometer}, {hydrometer}, {pendulum}, etc.; a current
        gauge. Hydrometric

From The Collaborative International Dictionary of English v.0.48 [gcide]:

  Tachometer \Ta*chom"e*ter\, n. [Gr. ta`chos swiftness, speed
     (fr. tachy`s quick) + -meter: cf. F. tachom[`e]tre.]
     An instrument for measuring the velocity, or indicating
     changes in the velocity, of a moving body or substance.
     Specifically: 
     [1913 Webster]
     (a) An instrument for measuring the velocity of running water
         in a river or canal, consisting of a wheel with inclined
         vanes, which is turned by the current. The rotations of
         the wheel are recorded by clockwork.
         [1913 Webster]
     (b) An instrument for showing at any moment the speed of a
         revolving shaft, consisting of a delicate revolving
         conical pendulum which is driven by the shaft, and the
         action of which by change of speed moves a pointer which
         indicates the speed on a graduated dial.
         [1913 Webster]
     (c) (Physiol.) An instrument for measuring the velocity of
         the blood; a haematachometer.
         [1913 Webster]

From WordNet (r) 2.0 [wn]:

  tachometer
       n : measuring instrument for indicating speed of rotation [syn:
           {tach}]