Calibrating Argon Spectrum with MicroLab Spectrometer Model 141

Click For Summary
SUMMARY

The discussion focuses on calibrating the argon spectrum using a MicroLab Spectrometer Model 141. Users suggest alternatives to gas discharge tubes for calibration, including using chemicals with known absorption wavelengths, such as chlorophyll and lanthanide salts like Europium nitrate. Fluorescent lamps are also recommended due to their emission lines, particularly at 546.5 nm and 611.6 nm. Budget constraints are acknowledged, with participants emphasizing the availability of low-cost options for calibration.

PREREQUISITES
  • Understanding of spectral imaging techniques
  • Familiarity with the MicroLab Spectrometer Model 141
  • Knowledge of chemical absorption and emission properties
  • Basic principles of fluorescence and light transmission
NEXT STEPS
  • Research the calibration process for the MicroLab Spectrometer Model 141
  • Investigate the spectral properties of Europium nitrate and other lanthanide salts
  • Learn about the emission spectra of fluorescent lamps and their applications in spectroscopy
  • Explore the use of gas discharge tubes for spectral calibration
USEFUL FOR

Researchers, chemists, and laboratory technicians involved in spectroscopy, particularly those working with plasma analysis and seeking cost-effective calibration methods.

jagadeeshr
Messages
11
Reaction score
0
Hi,

I need some help to calibrate argon spectrum.

I have a MicroLab Spectrometer (Model 141) to obtain spectral images of argon plasma. To calibrate the spectral images, I need a reference of known wavelength.

Usually, a discharge tube is used to obtain the reference spectrum. However, I cannot procure it now due to budget issues.

Another method is to is to fill a vial with chemical of known absorption/transmittance wavelength, and place it in the spectrometer. The wavelength at which the liquid absorbs or transmits light can be used as a references to calibrate the unknown spectrum.

Can you suggest any chemical that absorbs or transmits light in the visible range (400 to 700 nm)?

I could only think of chlorophyll. Maximum absorption at 430 & 662 nm for chlorophyll a and 453 & 642 nm for cholorophyll b.
http://www1.biologie.uni-hamburg.de/b-online/e24/3.htm

Thank you
Jagadeesh
 
Last edited:
Chemistry news on Phys.org
You can get gas discharge tubes for a few dollars. I don't know your budget, but it will be hard to get anything cheaper than that. Better ones cost more, but that is always the case.

Optical filters can have very narrow transmission or absorption windows. Sodium, rubidium, ... in flames produce narrow lines.
 
mfb said:
You can get gas discharge tubes for a few dollars. I don't know your budget, but it will be hard to get anything cheaper than that. Better ones cost more, but that is always the case.

Optical filters can have very narrow transmission or absorption windows. Sodium, rubidium, ... in flames produce narrow lines.

Thanks for the reply. The project budget will be approved in March, until then no "official" purchases can be made. So, I was looking for cheap alternatives.
 
A few dollars looks quite cheap, and you might be able to use it at home afterwards if you buy it yourself.
 
How about Xe lamps? They have a sharp emission peak at 467 nm.

If you are looking for chemicals, try known lanthanides salts. Excite it with UV (around 375 nm) and most of the time you will see their emission. Terbium or Europium salts show sharp emission peak at around 545 nm and 612 nm, respectively. Terbium is a little bit costly, but Europium nitrate cost around $60 per gram.

I have Europium nitrate at hand. If you want, I can give you the spectrum.
Better yet, you can also try Fluorescent lamps. They contain Eu3+ doped Y2O3 that emits in 610 nm or something.
 
Fluorescent lamps also show the lines of mercury.
 
Well of course, they are low vapor mercury lamp.