Fluorescent Lamp

A <span style="margin: 0px; padding: 0px; border: 0px; font-variant-numeric: inherit; font-variant-east-asian: inherit; font-weight: 700; font-stretch: inherit; line-height: inherit; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Lato, Helvetica, Arial, sans-serif; vertical-align: baseline;">fluorescent lamp, or <span style="margin: 0px; padding: 0px; border: 0px; font-variant-numeric: inherit; font-variant-east-asian: inherit; font-weight: 700; font-stretch: inherit; line-height: inherit; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Lato, Helvetica, Arial, sans-serif; vertical-align: baseline;">fluorescent tube, is a low-pressure <a href="https://en.wikipedia.org/wiki/Mercury-vapor_lamp" title="Mercury-vapor lamp" style="background-color: rgb(255, 255, 255); margin: 0px; padding: 0px; border: 0px; font-variant-numeric: inherit; font-variant-east-asian: inherit; font-stretch: inherit; line-height: inherit; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Lato, Helvetica, Arial, sans-serif; vertical-align: baseline; color: rgb(107, 75, 161);">mercury-vapor</a> <a href="https://en.wikipedia.org/wiki/Gas-discharge_lamp" title="Gas-discharge lamp" style="background-color: rgb(255, 255, 255); margin: 0px; padding: 0px; border: 0px; font-variant-numeric: inherit; font-variant-east-asian: inherit; font-stretch: inherit; line-height: inherit; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Lato, Helvetica, Arial, sans-serif; vertical-align: baseline; color: rgb(107, 75, 161);">gas-discharge lamp</a> that uses <a href="https://en.wikipedia.org/wiki/Fluorescence" title="Fluorescence" style="background-color: rgb(255, 255, 255); margin: 0px; padding: 0px; border: 0px; font-variant-numeric: inherit; font-variant-east-asian: inherit; font-stretch: inherit; line-height: inherit; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Lato, Helvetica, Arial, sans-serif; vertical-align: baseline; color: rgb(107, 75, 161);">fluorescence</a> to produce visible light. An <a href="https://en.wikipedia.org/wiki/Electrical_conduction_in_gases" title="Electrical conduction in gases" class="mw-redirect" style="background-color: rgb(255, 255, 255); margin: 0px; padding: 0px; border: 0px; font-variant-numeric: inherit; font-variant-east-asian: inherit; font-stretch: inherit; line-height: inherit; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Lato, Helvetica, Arial, sans-serif; vertical-align: baseline; color: rgb(107, 75, 161);">electric current</a> in the gas <a href="https://en.wikipedia.org/wiki/Excited_state" title="Excited state" style="background-color: rgb(255, 255, 255); margin: 0px; padding: 0px; border: 0px; font-variant-numeric: inherit; font-variant-east-asian: inherit; font-stretch: inherit; line-height: inherit; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Lato, Helvetica, Arial, sans-serif; vertical-align: baseline; color: rgb(107, 75, 161);">excites</a> <a href="https://en.wikipedia.org/wiki/Mercury_(element)" title="Mercury (element)" style="background-color: rgb(255, 255, 255); margin: 0px; padding: 0px; border: 0px; font-variant-numeric: inherit; font-variant-east-asian: inherit; font-stretch: inherit; line-height: inherit; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Lato, Helvetica, Arial, sans-serif; vertical-align: baseline; color: rgb(107, 75, 161);">mercury</a> vapor, which produces short-wave <a href="https://en.wikipedia.org/wiki/Ultraviolet" title="Ultraviolet" style="background-color: rgb(255, 255, 255); margin: 0px; padding: 0px; border: 0px; font-variant-numeric: inherit; font-variant-east-asian: inherit; font-stretch: inherit; line-height: inherit; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Lato, Helvetica, Arial, sans-serif; vertical-align: baseline; color: rgb(107, 75, 161);">ultraviolet</a> light that then causes a <a href="https://en.wikipedia.org/wiki/Phosphor" title="Phosphor" style="background-color: rgb(255, 255, 255); margin: 0px; padding: 0px; border: 0px; font-variant-numeric: inherit; font-variant-east-asian: inherit; font-stretch: inherit; line-height: inherit; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Lato, Helvetica, Arial, sans-serif; vertical-align: baseline; color: rgb(107, 75, 161);">phosphor</a> coating on the inside of the lamp to <a href="https://en.wikipedia.org/wiki/Fluorescence" title="Fluorescence" style="background-color: rgb(255, 255, 255); margin: 0px; padding: 0px; border: 0px; font-variant-numeric: inherit; font-variant-east-asian: inherit; font-stretch: inherit; line-height: inherit; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Lato, Helvetica, Arial, sans-serif; vertical-align: baseline; color: rgb(107, 75, 161);">glow</a>. A fluorescent lamp converts electrical energy into useful light much more efficiently than <a href="https://en.wikipedia.org/wiki/Incandescent_light_bulb" title="Incandescent light bulb" style="background-color: rgb(255, 255, 255); margin: 0px; padding: 0px; border: 0px; font-variant-numeric: inherit; font-variant-east-asian: inherit; font-stretch: inherit; line-height: inherit; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Lato, Helvetica, Arial, sans-serif; vertical-align: baseline; color: rgb(107, 75, 161);">incandescent lamps</a>. The typical <a href="https://en.wikipedia.org/wiki/Luminous_efficacy" title="Luminous efficacy" style="background-color: rgb(255, 255, 255); margin: 0px; padding: 0px; border: 0px; font-variant-numeric: inherit; font-variant-east-asian: inherit; font-stretch: inherit; line-height: inherit; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Lato, Helvetica, Arial, sans-serif; vertical-align: baseline; color: rgb(107, 75, 161);">luminous efficacy</a> of fluorescent lighting systems is 50–100 lumens per watt, several times the efficacy of incandescent bulbs with comparable light output.