"discharge tube." YourDictionary, n.d. Web. 08 December 2018. <https://www.yourdictionary.com/discharge-tube>.
discharge tube. (n.d.). Retrieved December 08th, 2018, from https://www.yourdictionary.com/discharge-tube
A closed vessel having electrodes at either end and containing a gas at low pressure. When a sufficient voltage is applied to the electrodes, an electric current flows through the gas. Discharge tubes can be used to prevent current flow below a certain voltage; they can also function as lamps by the use of ionizing gas, which glows when current flows through the tube.