nOzonoscope(Chem) An apparatus employed to indicate the presence, or the amount, of ozone.
Century Dictionary and Cyclopedia
nozonoscopeA test-paper which is oxidized and discolored by ozone. When properly exposed, the degree of discoloration indicates the relative amount of ozone in the air. Ozone-papers are usually either red litmus-paper dipped in a dilute solution of potassium iodide, or paper saturated with a mixture of potassium iodide and starch. In the litmus-paper the ozone decomposes the potassium iodide and combines with the potassium, forming potash, by which the red litmus is rendered blue. In the iodized starch-papers, the ozone combines with the potassium, and the free iodine combines with the starch, forming a blue iodide of starch.
Webster's Revised Unabridged Dictionary
Ozone, + -scope,
Critical examination of ozonoscopes.
"Scientific American, Vol. XXXIX.--No. 24. [New Series.], December 14, 1878" by Various