Working of Hollow Cathode Lamp [How HCL are used]
Hollow Cathode Lamps are ideal source of spectral lines that are used for testing in laboratories. Hollow Cathode Lamps working totally depends on the hollow cathode effect. Hollow Cathode Effect was first observed in 1916 by Friedrich Paschen, a German physicist, known for his work on electrical discharges. Basically Hollow Cathode Effect is electrical conduction at lower voltage. Apart from HCLs, Hollow Cathode Effect gets used in neon signages as well.
Typical Hollow Cathode Lamp Setup
An HCL is formed of a Glass Tube that contains an anode, a cathode and inert gas. When Voltage gets passed through the anode, the inert gas gets ionized. Due to creation of plasma from the inert gas, sputtering of atoms from the cathode takes place as inert gas ions get bombarded on the cathode.
The excited atoms of the inert gas and cathode are used for detection and to measure the spectrum while testing.
Advantages of Hollow Cathode Lamps [Why HCL in AAS?]
- Better Lifetime compared to other lamps
- Low Noise & hence better spectral response
- Stability in the light output
Some of the benefits of choosing Heraeus made HCLs are,
- Substantially Low Price
- Variety of single- and multi-element coded / non-coded in low and high-current, 37 mm and 50 mm lamps
- Long life due to higher gas volume
- Clear signals and low distortion due to special cathode technology
- Can be used for almost any AA instrument
Heraeus’ lamps are also compatible with all major Atomic Absorption Spectrophotometry including:
- Analytik Jena
- Perkin Elmer
- Thermo Fischer
Various benefits of Hollow Cathode Lamps makes it ideal for usage in AAS.
Culled from HTPC website
Posted by Oluwakemi Adi