Fourier transform infrared spectroscopy, also commonly known as FT-IR is a preferred method for infrared spectroscopy, which uses the mathematical Fourier transform process to convert the raw data “interferogram” into the actual spectrum.
An infrared beam containing various frequencies of light will pass through the sample, and the amount of IR light absorbed by the sample is measured. Then the process is repeated many times with different combinations of IR light frequencies. An Interferometer, a fixed mirror & a moving mirror are used to create an interferogram which has the unique property that every data point (a function of the moving mirror position) has the information about every infrared frequency which comes from the IR source. Then computer processing with Fourier transform takes place to convert the raw data (light absorption for each mirror position) into the desired result (light absorption for each wavelength). High purity gases, like nitrogen & synthetic air, will be required as purge gas and zero gas. Multiple cylinders of high accuracy gas mixtures at multiple concentrations will be required to generate the required calibration curves for the instrument.
Fourier transform infrared spectroscopy (FT-IR) instrumentation gas finder
Detection limit |
Gas recommendation |
Regulator recommendation |
Gas generator recommendation |
Calibration gas mixtures | |||
≤ 1 ppm | HiQ Accredited Mixtures | REDLINE C200 series | n/a |
≤ 1 ppm | HiQ Car Exhaust Control Mixtures | REDLINE C200 series | n/a |
≤ 1 ppm | HiQ environmental Mixtures | REDLINE C200 series | n/a |
≤ 1 ppm | HiQ Hydrocarbon Mixtures | REDLINE C200 series | n/a |
Purge gas | |||
≤ 1 ppm | HiQ Nitrogen 5.0 | BASELINE C106 series | HiQ MISTRAL Nitrogen |
≤ 1 ppm | HiQ Synthetic Air 5.0 Zero | BASELINE C106 series | HiQ Zero Air |
Zero Gas | |||
≤ 1 ppm | HiQ Nitrogen 5.0 Zero | BASELINE C106 series | HiQ MISTRAL Nitrogen |
≤ 1 ppm | HiQ Synthetic Air 5.0 Zero | BASELINE C106 series | HiQ Ultra Zero Air |