| Author | Message | ||
     Saf Ahmed (Saf) |
I am a research student for a small company based in the UK. The aim of the project is to capture molecular frequencies of any substance, record and digitise them using a computer equipped with a sound card. What devices, analytical instrumentation and software is required for me to carry out this research. Is it easy to setup? My reserach on the internet led me to the understanding that I will require a Raman Spectrometer. I sincerely appreciate your time and effort. | ||
| MPDC |
What kind of frequencies are you talking about? Surely a sound card can only detect frequencies in the +/- 10Hz to 20 KHz range(audible). | ||
| Saf Ahmed (Saf) |
The frequency in question is the resonating frequency of any particular molecule. I know that water has a resonating frequency of 140Hz. Is there equipment available to boost the frequency so that one can hear it audibly via a special amplifier? | ||
| hlmark |
Saf - actual vibration frequencies of atoms within molecules are on the order of 10^14, orders of magnitude above the frequency you mention and far too high to directly measure. For this reason, secondary physical phenomena are used to detect the vibrations. Some of the most common ones are infrared spectroscopy, near infrared spectroscopy and Raman spectroscopy. These all work by measuring the effect of the vibrations on electromagnetic waves that interact with the vibrations, the strength of the interactions at different optical wavelengths are used to determine the frequencies and strengths of the underlying atomic and molecular vibrations. This is, in one sense, an indirect measurement, but it is the one most commonly used for this purpose. The different types of spectroscopy are sensitive to somewhat different characteristics of the underlying vibrations, and also some other characteristics of the molecules (such as dipole moments and polarizability) I think you need some more guidance in these matters; you should contact a local university to see if they have a course you can take. Alternatively there are short courses given at some of the major analytical conferences, such as Pittcon, EAS and FACSS - unforutnately you just missed the EAS conference, which was held at the beginning of this week. If you wish to contact me off the discussion group we can further discuss possibilities. Howard \o/ /_\ | ||
| lois_weyer |
It "sounds" to me that you must be referring to ultrasound transmission or absorption, which is not the same as molecular vibrations and is unrelated to Raman. Ultrasound measurements will give you some measure of the compressibility of liquids or solutions, something like density. It can be useful for measuring water and some binary mixtures, but not alot else. |