Apparatus and methods for making spectroscopic measurements of cathode fall in fluorescent lamps
View Patent ↗Apparatus and methods are disclosed for measuring cathode fall within a fluorescent lamp that contains an electrode and a gas. A level of cathode fall associated with the electrode may be identified based on an intensity and wavelength of radiation emitted by the gas.
1. A method for measuring cathode fall voltage within a fluorescent lamp that contains an electrode and a gas, the method comprising:
detecting radiation emitted from the gas; and
identifying a level of cathode fall voltage associated with the electrode based on an intensity and wavelength of the detected radiation.
2. The method of claim 1 , further comprising identifying that the cathode fall voltage has exceeded an excitation potential that corresponds to the wavelength of the emitted radiation.
3. The method of claim 1 , further comprising identifying that the cathode fall voltage has exceeded an excitation potential associated with a metastable state of the gas.
4. The method of claim 1 , further comprising identifying that the cathode fall voltage has exceeded an excitation potential associated with a 4p state of the gas.
5. The method of claim 1 , further comprising identifying that the cathode fall voltage has exceeded an excitation potential associated with a 5p state of the gas.
6. The method of claim 1 , further comprising identifying that the cathode fall voltage has exceeded an excitation potential associated with a metastable state of the gas and that stepwise excitation to a 5p state of the gas is occurring.
7. The method of claim 1 , further comprising identifying that the cathode fall voltage has exceeded an excitation potential associated with a metastable state of the gas and that stepwise excitation to a 4p state of the gas is occurring.
8. The method of claim 1 , further comprising identifying that the cathode fall voltage has exceeded an excitation potential associated with a 4p state of the gas and that direct excitation to the 4p state is occurring.
9. The method of claim 1 , further comprising identifying that the cathode fall voltage has exceeded an excitation potential associated with a 5p state of the gas and that direct excitation to the 5p state is occurring.
10. The method of claim 1 , wherein the gas includes at least one of helium, neon, argon, krypton, and xenon.
11. The method of claim 1 , wherein the gas includes argon, and the radiation has a wavelength of at least one of about 420.0 nm and about 811.5 nm.