Bunsen lighter

November 2, 2021

The bunsen burner is a very important laboratory instrument. Today it is displaced by electrical equipment, but in its time, it allowed the discovery of new substances and facilitated work in the laboratory. It is used for heating and sterilization.

What is it?

It is an instrument used for the purpose of heating, sterilizing or combustion of samples or chemical reagents. It was invented by Robert Bunsen in 1857. This instrument provides a very fast transmission of high intensity laboratory heat.

It is a natural gas or liquefied petroleum gas burner. The flame it produces is adjustable as it has knobs that regulate the gas and oxygen mixture.

Its design began in 1852 when the University of Heidelberg hired Bunsen and offered him a new laboratory building. As gas began to be used for lighting, the university provided the laboratory with a gas supply for the burners. These burners were not efficient, so in late 1854, Bunsen suggested design principles to the university mechanic, Peter Desaga, who built a prototype of the burner.

This lighter was efficient at generating heat, it reduced the soot generated and the flame was not too bright.

Gustav Kirchhoff and Robert Bunsen built a spectroscope in 1860 to analyze the light patterns caused by heating substances in the lighter. This allowed the discovery of cesium, thallium, rubidium, and indium.


The burner has a heavy base into which the gas supply is inserted. From there there is a vertical tube through which the gas flows. On the sides of the tube there are adjustable perforations that allow air to enter, achieving a flammable mixture at the top of the tube.

It allows to obtain temperatures of 1500 ºC. The gas inlet is regulated by a needle valve.

In this way the amount of gas and the heat of the flame are controlled by adjusting the size of the hole in the base of the tube. If we allow more air to pass into the mixture with the gas, the flame will burn at a higher temperature and will acquire a blue hue.

If the side holes are closed, the gas will only mix with atmospheric oxygen, which is why a less efficient, colder and red flame is achieved. It is a dirty flame that leaves soot on the surface that is being heated. If the gas input is increased, the size of the flame will grow, but its temperature will drop because the extra amount of gas will continue to mix with the same amount of oxygen.

It is lit with a match or a spark lighter.

What is it for?

It can be used to perform the analysis of substances identifying how the flame alters, its fusibility and its volatility. For this there are reaction zones in the flame:

  • Flame base: Low temperature. It is used to investigate the presence of volatile substances that can color the flame.
  • Melting Zone: Used to investigate fusibility and volatility.
  • Lower oxidizing zone: it is used for the oxidation of dissolved substances in a vitreous flow.
  • Lower reducing zone: It is used to carry out reductions on charcoal or with vitreous flow.
  • Upper reducing flame: it is the luminous tip of the inner cone of the flame. It is produced by reducing air access. It allows to reduce oxides in the form of incrustations.
  • Upper oxidizing flame: It is the non-luminous area of ​​the flame. It works best when the air inlet holes are open. It is used in oxidation tests, to release volatile products and for oxidation processes that do not require excessively high temperatures.

Fusibility tests make it possible to determine at what temperature some substances melt. To determine the different temperatures of the flame, the light emitted by a platinum wire when it comes into contact with the flame is analyzed.

  • Incipient red 525 ° C.
  • Dark red 700 ° C.
  • Cherry red 950 ° C.
  • Yellowish red 1100 ° C.
  • Weak white red 1300 ° C.
  • Bright white red 1500 ° C.

Bunsen Burner Precautions

  • Before using the lighter you must recognize which pipe supplies gas and which hose is connected.
  • The lighter must be handled by a single person.
  • The match must be lit before opening the gas supply tap.
  • The rubber hose should not wrap around the lighter.
Dr. Loony Davis5
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Born and raised in Brussels in an English family, I have always lived in a multicultural environment. After several work experiences in marketing and communication, I came to Smart Water Magazine, which I describe as the most exciting challenge of my career.
I am a person with great restlessness and curiosity to learn, discover what I do not know, as well as reinvent myself daily, someone who is curious about life and wants to know. I enjoy sharing knowledge.
This is my personal project but I also collaborate in other blogs, it is the case, the most important web on water currently exists in the US, if you are interested you can read my articles here.

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