Automated FTIR gas analyzer

A system for certifying to a user a concentration of gas in a cylinder comprising:

• a gas cell configured to receive a sample gas from a cylinder,
• an FTIR (Fourier Transform Infrared) spectrometer coupled to the gas cell for scanning the sample gas and forming a beam spectrum,
• a processor coupled to the FTIR spectrometer for calculating an intensity response of the sample gas based on the beam spectrum,
• a storage device for storing data points of a plot of intensity response of a known gas versus concentration levels,
• wherein the processor is configured to interpolate between the stored data points of the plot to determine an interpolated data point corresponding to a resultant intensity response of the sample gas, and
• provide to the user a concentration level of the sample gas based on the interpolated data point,
• the gas cell is configured to receive a standard gas from a cylinder and a zero gas from another cylinder,
• the FTIR spectrometer is configured to scan the standard gas and the zero gas,
• the processor is configured to calculate an intensity response of the standard gas and an intensity response of the zero gas, and
• the resultant intensity response of the sample gas is calculated based on a sequence of first, second and third tests;
• wherein the first test includes a scan order of scanning first the zero gas, second the standard gas, and third the sample gas, and then computing a first correction,
• the second test includes a scan order of scanning first the standard gas, second the zero gas, and third the sample gas, and then computing a second correction,
• the third test includes a scan order of scanning first the standard gas, second the sample gas, and third the zero gas, and then computing a third correction, and
• the resultant intensity response is based on the first, second and third corrections.

A system for certifying to a user a concentration of gas in a cylinder comprising:

• a gas cell configured to receive a sample gas from a cylinder,
• an FTIR (Fourier Transform Infrared) spectrometer coupled to the gas cell for scanning the sample gas and forming a beam spectrum,
• a processor coupled to the FTIR spectrometer for calculating an intensity response of the sample gas based on the beam spectrum,
• a storage device for storing data points of a plot of intensity response of a known gas versus concentration levels,
• wherein the processor is configured to interpolate between the stored data points of the plot to determine an interpolated data point corresponding to the intensity response of the sample gas, and
• provide to the user a concentration level of the sample gas based on the interpolated data point,
• a gas divider is disposed between the gas cell and the cylinder for diluting the concentration of the sample gas in the cylinder, and
• when the sample gas in the cylinder has a concentration level greater than the concentration levels of the known gas stored in the storage device, then the gas divider is configured to dilute the sample gas before scanning.