Nernst LampA new form of incandescent light for homes and medical usesHistory (1897 - 1980s)

 Introduction & Statistics

 How They Work

 Inventors and Developments

 

 

The nernst lamp was invented as an improvement to the existing incandescent lamp. It lasted longer and had improved efficiency. The lamp became a serious competitor to standard bamboo and cellulose filament incandescent bulbs at the time. The nernst lamp was created by a physicist not an untrained tinker. This was actually an important trend of the 1890s. Simple trial and error methods used by Thomas Edison would not be able to create such a sophisticated device. The success of engineer/inventors equipped with the latest in scientific knowledge acquired in Germany and Switzerland sent a powerful message to the rest of the world that we are in a new age of technology. Because of market threat from the nernst lamps(Sold by Nernst in Europe and Westinghouse in US) and tantalum filament lamps (owned by Siemens & Halske), General Electric founded the GE Research Lab and hired people of every nationality to work together. Corporations knew they had to trust and invest in the 'new' breed of engineer to keep them afloat.

Statistics*Lumens per watt: 6-9*Lamp life: 450 - 1200 hours*CRI 100*Color Temperature ~3000

Common uses: indoor lighting, specific medical uses where infrared light is needed

This light is now obsolete. Nernst lamp heyday was 1900 - 1913. They are no longer produced.

 

1. How They Work 2. Inventors and Developments

 1. How they work

Nernst Lamp uses a small ceramic rod that was heated to incandescence. The lamp is also called a incandescent "glower". Ceramic does not oxidize like metal, so it did not need to be enclosed in a bulb.

Our video about the nernst lamp is the best way to understand how it works.

First the heater tubes would rise in temperature to the point of a soft red glow. This would prepare the glower. When the glower reached a certain temperature the resistivity dropped to the point where current would begin to flow through it. At this point a shifter or switch would stop providing power to the heater tubes and all current would flow through the glower (see the video of the schematic  below ). The glower created a nice pure white light similar to a halogen lamp today.

Longer Life:The point of the bulb in regular incandescent lamps is to create a vacuum around the filament to prevent the filament from oxidizing which lengthens the life of the filament. In a nernst lamp the glower had a longer life than the incandescents of the time. The glower could be replaced, boxes of replacement glowers were sold. This was much more practical than replacing the whole lamp head unit (see the illustration left).

The ballast is made of pure iron wire in a glass bulb filled with hydrogen gas (to prevent rust). It is a simple resistor.

Schematic of how the lamp works: (embedded Youtube video)

 

Type A Nernst Lamp:coiled ceramic glower

Type C lamp. Westinghouse ended up buying the license to sell the lamp in North America. This illustration above shows a large nernst lamp with 6 glowers. This would allow the lamp to be placed on high ceiling interior locations where it could replace the already popular carbon arc lamp. This meant that the nernst

lamp was competition for older small and large area lighting systems.

 2. Inventors and Developments

Walther Nernst

The Nernst Lamp was invented by Walther Nernst in Göttingen, Germany in 1897. This lamp emits a natural light, close to the daylight spectrum, unlike incandescent bulbs.

Nernst was born Briesen in West Prussia (close to the same region as Charles Steinmetz) and studied in Zurich, Berlin, Wuerzburg. He founds the Institute of Physical Chemistry and Electrochemistry at Göttingen in 1897. He worked on many other technologies and with a heavy background in science he helped steer engineering into a new age. He was a outspoken opponent of Nazism and Adolf Hitler, and as a result lost his job as a scientist and died poor in 1941.

*Nobel Laureate Irving Langmuir studied under Walther Nernst in Göttingen and helped him develop the Nernst lamp. Langmuir went on to work for GE and greatly improve the incandescent

lamp. (see the Incandescent Lamp section above)

Continued Use Today:The "Nernst Glower" was important for use in the medical field in infrared spectroscopy until the 1980s.

Neon and Argon LampsAn early form arc discharge lightingHistory (1898 - today)

The Neon lamp is a low pressure gas discharge lamp. It is a cold cathode fluorescent lamp (CCFL). The term "Neon Lamp" is used to describe a CCFL with a tube diameter less than 15 millimeters. Due to the great popularity and ubiquity of the neon lamp we consider it one of the 12 main types of electric lamps in this History of the Electric Lamp.

All credits and sources are located at the bottom of each lighting page

Advantages

*Good lumen per watt performance

 Introduction & Statistics  Colors

 How They Work  Inventors and Developments

 

*Neon performs more reliably in cold weather than hot cathode fluorescent lights*More reliable than LEDs for airport runway landing lights

50 Lumens per watt (red)65 Lumens per watt (green)

Disadvantages

*Shape of tube is a limitation*Argon is not reliable in cold temperatures*Diffused light (not good for any focused beam applications)

Below: Video on Neon Lamps (Youtube must not be blocked on your server for this to work)

Statistics*Lumens per watt: 50 - 65*Lamp life: 25,000 hours*CRI (for white lamps only) 70 *Color Temperature (for white lamps): ~5000

Common uses: signs, accent lighting, highlighting building features

 

1. How it Works 2. Colors3. Inventors

and Developments

 1. How it Works

The classic neon lamp is made of a glass tube containing a mixture of neon (99.5%) and argon gas. There are two electrodes, one positive, and the other negative. Voltage rises and an arc is struck between. Argon gas is used in other fluorescents as well because of a lower striking temperature. After the argon strikes an arc the neon gas is warmed and current is able to flow through the neon gas, ionizing more molecules as the current rises. A ballast is necessary to limit the current since resistance will continue to drop as current rises. See how it works in the video.

Other "Neon" Lamps:

People use the term 'neon sign' to describe CCFLs of all colors. Other colors may not use neon. They may use helium, xenon, or other nobel gases. Today most other colors work by using mercury vapor. This type of lamp was invented 3 years after the neon lamp (1901). First argon strikes the arc, this heats up and vaporizes mercury stuck to the sides. The arc then goes through mercury vapor, which creates UV light. The UV light excites the colored phosphor and you get your desired colored light. The mercury vapor lamp is one of the main 12 kinds of lamps and you can read more about ithere. We recommend you continue reading below before moving on to mercury vapor lamps.

The neon lamp works on AC or DC power. Interestingly when using the lamp with DC, only one of the electrodes will glow since ions are formed off of that electrode. AC power provides a nice uniform look with a glow evenly distributed.

Applications:

Plasma monitors/televisionsSignsIndicator LightsNumeric Indicators (Nixie Tubes)Mechanical Scan TelevisionsAC or DC indicator

Left: Neon signs use the top 5 gases from the nobel inert gases

Colors:

While in the past a great variety of gases and phosphors were used to create signs of various colors, today there are more effective phosphors which will work simply with mercury/argon lamps. The mercury vapor is a more efficient lamp and is desired over other gas fillings like xenon and helium. You can still get lamps with a variety of nobel gases.

Clear red - neon

Red opaque - Neon Gas with red phosphor

Neon + Argon + Hg combination used for outdoor use in order to function more reliably in cold weather

Blues, Greens, yellow- phosphor with Argon and Mercury Gas (Argon starts the arc, warms up, then mercury gas ionizes, UV light is emitted) UV activates the colored phosphor

Pinkish white and white - Helium gas in a clear tube, or you can use Hg vapor with a white phosphor

Orange - Neon Gas with yellow phosphor

 

Yellow - can also be created with helium and a yellow phosphor

Other Colors in a clear tube:Krypton - Whitish-Green

Xenon - bluish-white

 2. Inventors and Developments

The neon lamp was discovered in 1898, however its roots lie in the early experimental cold cathode tubes created in the 1850s and later. Georges Claude contributed the most to the neon lamp but all the engineers below deserve recognition.

1857 Heinrich Geissler - father of fluorescent lamps: developed a glass tube with partial vacuum with two electrodes on each end. He experimented with electric arcs through different types of gasses. The "Geissler Tube" created an impressive soft colored glow and is the basis for many kinds of lights today such as the Mercury Vapor Lamp, Neon Lamp, Fluorescent Lamp, Metal Halide Lamp, and Sodium Lamp

1898 William Ramsay & Morris W. Travers - discovered the neon lamp at a time when neon was a very rare naturally created gas. They moved on to other experiments and did not see the lamp as remotely cost effective.

1904 Daniel McFarlan Moore - first commercial installation of the "Moore Tube": a predecessor to the fluorescent lamp and neon lamp. He uses and arc through nitrogen and carbon dioxide gas to make light.

1915 Georges Claude - around 1902 discovers how to create neon gas during his work on liquefying air. Claude is aware of the work of George McFarlan Moore in New Jersey, and he creates a "Moore Tube" with neon gas. After further work he displays the first modern neon lamp in 1910 a the Paris Motor Show (Salon de l'Automobile et du Cycle). By 1915 Claude creates his own unique and reliable neon lamp. he corners the market until the 1930s. He later is condemned for being a fascist and sympathizing with the Nazis.

1917 Daniel McFarlan Moore - (General Electric) Moore again makes his mark on lamp history by inventing the negative glow neon lamp. He creates small bulbs with two electrodes, neon gas glows immediately around the electrodes. This is used as indicator lights on many devices until it is replaced by the LED in the 1960s. It is still used in decorative Christmas lights since the red light flickers and dances between electrodes similar to a flame.Photo: Schenectady Museum www.SchenectadyMuseum.org

The first HID lampHistory (1901 - Today)All credits and sources are located at the bottom of each lighting page

 Introduction & Statistics

 How They Work

 Inventors and Developments

Introduction:

The mercury vapor lamp is a high intensity discharge lamp. It uses an arc through vaporized mercury in a high pressure tube to create very bright light directly from it's own arc. This is different from fluorescents which use the mercury vapor arc to create a weaker light that mainly creates UV light to excite the phosphors. The "Merc" as it is known has been a workhorse for society; lighting streets, factories and large areas for over 100 years.

Advantages:- Good efficiency (lamps after 1980s have a high lumen per watt rating)- Color rendering is better than that of high pressure sodium street lights- Some lamps last far longer than the 24000 hour mark, sometimes 40 years

Disadvantages:- Like many lamps it contains traces of mercury which must be disposed of properly- HPS streetlights have a better lumen per watt rating- Human skin looks green under the light, it is poor for color film/photography-Warm up time required to start the lamp

Statistics*CRI 20 (clear bulb) 60 (phosphor coated)*Color Temperature - 6800 K (clear bulb)*Lumens per watt: 30-60*Lamp life: 24,000 - 175,000 hours*Available in 40-1000 W

Common uses: large areas like parks, street lighting, high ceiling buildings, gyms. Low pressure lamps with a quartz envelope are used for germicidal purposes since they allow UV light to pass.

Left: Mercury Vapor with phosphor for improved color

1. How it works 2. Inventors and Developments

 Video:

 1. How it Works

Above is a "Lifegaurd" brand lamp by Westinghouse, it needs a ballast to run.

UV rays are produced, but blocked by the borosilicate glass.

There are several versions of the lamp but the basic principle is the same.

Low Pressure:

The first mercury vapor lamps were in a lower pressure tube. One would tip the lamp, and electrical contacts on each side of the lamp would send electricity through a liquid mercury which started the lamp. After that the lamp would heat fast and mercury became a vapor. The light would intensify as the arc grew stronger in the tube.

High Pressure:

Lamps of today are high pressure lamps with a fused quartz inner discharge tube. The high pressure helps increase efficiency and this was developed in 1936, 35 years after the low pressure lamps came out.

This lamp start with a small arc between the starting electrode and the main electrode. This arc goes through argon gas which easily strikes, even in cold weather. This little arc heats the tube, and over several minutes the tube gets hot enough to vaporize the solid mercury stuck to the sides. The mercury vaporized creates a strong light between the two main electrodes. (see graphic to the left)

To prevent the arc from infinitely getting stronger a ballast limits the current. Some lamps are "Self Ballasted", they use an incandescent filament to act as a resistor, limiting current. Home lighting fixtures usually use the self-ballasted type where as the more expensive but more efficient ballasted lamps are found in large fixtures for municipal lighting.

The photo below shows a self-ballasted lamp, notice the tungsten filament.

In this clear bulb zinc and cadmium are metals used along with the mercury to help color and brightness.

A Mercury Vapor with a transformer (ballast) build into the base.

The bulb at left is just warming up, the bulb at right is after a few minutes of warming. This bulb has phosphor to help make the light more of a true white color. It can take several minutes to warm up.

Left: small amounts of mercury visible on a large discharge tube.\Right: older heavy ballast for a standard ceiling mounted merc fixture

 2. Inventors

1835 - Tested mercury vapor arcs in air at common atmosphereCharles Wheatstone (London) worked with arcs through mercury during this tests in spectropy. He would create an arc through a metal, then observe what colors it produced when a prism separated the light into it's individual frequencies.

1860 - Developed a rudimentary mercury vapor lampJohn Thomas Way (London) Developed a mercury vapor lamp. He tested them on the Hammersmith Bridge in London.

1892 - Developed an experimental mercury vapor lampLeo Arons, (University of Berlin). His lamp worked fine but had a green blue color that was not acceptable to most people.

1901 - The First Commercial Mercury Vapor LampPeter Cooper Hewitt (New York City) had a history of innovations in other fields, and when he set about on the project of the mercury vapor lamp in 1898 it only took 3 years to develop the first reliable lamp with a acceptable color of light. His work was a commercial success and eventually his company and patents were bought out by General Electric in 1913.

An early mercury vapor lamp. One would tip the light to get it to start. These early low pressure lamps used a lot of mercury, today's lamps use a tiny amount of mercury. Right around 1900 the mercury arc rectifier was developed, this luminous device was very important for power conversion. NYC subways were still using original mercury arc rectifiers to convert AC to DC power up until the end of the 20th century. (Read more about theMercury Arc Rectifier)

Later Cooper Hewitt mercury vapor tubes and historic fixture

1906 - Higher pressure mercury vapor light in a fuzed quartz tube is developedKuch & Retschinsky (Siemens, Munich)

1936 - The modern high-pressure mercury vapor lamp is developed, type MBPhilips (Nederlands) No individual names are available