spectrumtube
nounUK /ˈspɛktrəm tjuːb/
US /ˈspɛktrəm tuːb/
A glass tube that glows with bright colors when electricity goes through it.
In science class, we watched the spectrum tube light up with a purple glow.
RELATED WORDS
OTHER MEANINGS
2. A sealed tube filled with gas used to study the colors of light each gas gives off.
The teacher used a spectrum tube to show the different colors of hydrogen.
3. A lamp that makes colored light by passing electricity through a gas.
The sign outside the shop was lit by a spectrum tube.
4. A small glass tube used in science labs to identify gases by their glow.
Each spectrum tube glowed a different color, helping us tell the gases apart.