What is hollow cathode lamp?

A hollow cathode lamp is a type of gas discharge lamp used in atomic absorption spectroscopy and other analytical techniques. It consists of a cylindrical metal tube filled with a noble gas, typically argon or neon, at low pressure. Inside the tube, there is a small piece of the metal or element to be analyzed, known as the cathode.

When a high voltage is applied to the lamp, the noble gas is ionized, creating a plasma that excites the atoms of the metal or element in the cathode. This excitation produces specific wavelengths of light characteristic of the metal or element. These wavelengths can be used to identify and quantify the presence of the metal or element in a sample.

Hollow cathode lamps are known for their high sensitivity, low background noise, and narrow spectral lines, making them ideal for trace elemental analysis. They are commonly used in analytical chemistry laboratories for determining the concentrations of metals in a variety of samples, such as environmental samples, biological samples, and industrial materials.