An atmospheric sensor on Sikaris
The Sikarian atmospheric sensor was a type of atmospheric sensor used on the planet Sikaris.
It emanated sounds and also looked like a musical instrument, but it wasn't one, as the frequencies of the chimes it emanated indicated changes in the weather conditions of Sikaris. It worked on the principle of non-linear resonance, by adjusting to the dynamic variables in the atmosphere.
In 2371, Eudana showed Harry Kim of the USS Voyager how to use the atmospheric sensor. (VOY: "Prime Factors")
The hand-held tool was previously used as part of the Exocomp in the Star Trek: The Next Generation episode "The Quality of Life" and was made from a part of a Romulan phaser rifle. It was later sold off on the Profiles in History auction. [1]