Actinometer

2 definitions found

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

  Actinometer \Ac`ti*nom"e*ter\, n. [Gr. ?, ?, ray + -meter]
     (a) An instrument for measuring the direct heating power of
         the sun's rays.
     (b) An instrument for measuring the actinic effect of rays of
         light.
         [1913 Webster]



From WordNet (r) 2.0 [wn]:

  actinometer
       n : an instrument for measuring the intensity of electromagnetic
           radiation (usually by the photochemical effect)