Infrared transmission flow cell with thermal ramping capability

A method to measure a liquid analyte with a weak absorbance in a prescribed reference solution with a very high absorbance, comprising:

• alternatively flowing the liquid analyte and the prescribed reference solution through a fluid chamber in a liquid flow cell;
• restricting flow of an output of the liquid flow cell along tubing carrying the output of the liquid flow cell;
• emitting an infrared (IR) light from an IR light source, the IR light being filtered through an optical filter;
• transmitting the filtered IR light through a sample cell in the fluid chamber to produce a chamber signal;
• and
• using a detector having an optical range to detect the chamber signal.

A system to measure a liquid analyte with a weak absorbance in a prescribed reference solution with a very high absorbance, the system comprising:

• a tunable optical laser source configured to emit coherent light across a range of wavelengths;
• a liquid flow cell having a sample chamber with a chamber window, the liquid flow cell configured to alternatively receive the liquid analyte and the prescribed reference solution;
• a detector having an optical range to detect the chamber signal;
• and
• a restriction along tubing configured to carry output of the liquid flow cell.

A method to measure a liquid analyte with a weak absorbance in a prescribed reference solution with a very high absorbance, comprising:

• alternatively flowing the liquid analyte and the prescribed reference solution through a fluid chamber in a liquid flow cell to a waste vessel;
• pressurizing a headspace of the waste vessel above the waste liquid analyte and prescribed reference solution;
• emitting an infrared (IR) light from an IR light source, the IR light being filtered through an optical filter;
• transmitting the filtered IR light through a sample cell in the fluid chamber to produce a chamber signal;
• and
• using a detector having an optical range to detect the chamber signal.