IR Spectroscopy

Infrared spectroscopy is a principle for organic and inorganic chemistry analysis using infrared light interacting with a molecule. Infrared spectroscopy exploits the fact that molecules absorb specific wavelengths of light that are characteristic of their structure. Selected molecules have specific resonant frequencies where the absorption of radiation with proper wavelength is significantly higher in comparison to other parts of the spectra. The level of absorption at a given wavelength can be precisely measured and recalculated to the amount of the substance of interest. By transmitting a beam of IR radiation through the air, or through any particular gas volume, and recording how much is transmitted at selected spectral lines, one may decide which gases are present and how much of each.

Most gases have their characteristic spectra in the infrared spectrum. Those spectra derive from the molecule’s composition in such a way that no two molecular gases have the same IR spectrum. IR spectra are the fingerprints of gases and thus allow gases to be uniquely identified. Infrared wide-spectrum radiation is passing through the gas column. At the same time, the sampled gas is transported through the tube.

The infrared analyses used in our products are unique in the field of extremely short analytical tubes (just 80 mm), combined with highly sophisticated analog and software signal processing technology, capable of extracting the “invisible” signal from the surrounding noise level. This solution, originally applied in radar signal detection technologies, allows the use of an extremely small, short analytical tube to achieve the real detection limit at the hundreds of ppm level.

The special selection of the individual infrared sensors and customer-made sensor selective filter (as for the group of petroleum hydrocarbons, carbon dioxide, N₂O, H₂S, and precise reference channel and unique methane measuring channel, which spectral line is located at the wavelength where other infrared sensors do not operate) enables our new system to achieve the extreme sensitivity in this size of instrument case and, also, the unique capability of the infrared section to provide exclusive and sharp selectivity for the methane gas existing in the wide spectrum range of other organic compounds. Optional H₂S and N₂O channels enable the system for application in the very specific environmental investigation projects.

There is the additional advantage of our new infrared system solution that can be found in the signal processing and analog system dynamic range. Our infrared measuring channels work in the huge dynamic range from an unbelievable hundreds of ppm to 500 000 ppm without changing the measuring range; that is absolutely unique in the field of portable instruments. This unique feature enables the making of measurements of soil-sampled gas simultaneously and, what is more important, in one sampling, without the necessity to repeat the measurement if the measuring range of the (other) instrument would be selected improperly. “One-shot” measurement is extremely important in working in non-permeable soils, where the real amount of the gas sample is very limited and cannot be available for repeated measurement (with different measuring ranges). This feature makes the ECOPROBE system still unbeatable and very popular in real field use.