Gas equilibrium coil for providing, in real-time, a gas calibrating solution

1. A gas-solution equilibrium device for use in a liquid sample gas analyzer comprising:

a temperature-controlled, thermally-conductive mandrel;

a coil of gas-permeable tubing wrapped around the mandrel, the gas-permeable tubing having an inlet and an outlet; and

a housing having an internal space containing the temperature-controlled, thermally-conductive mandrel, the coil of gas-permeable tubing and a volume of gas wherein the coil of gas-permeable tubing has a predefined linear length and the gas-permeable tubing has a predefined wall thickness, the combination of which together is capable of equilibrating a liquid passing through the coil at a predefined flow rate with the gas within the internal space to provide a gas calibration solution in real time at the outlet of the tubing for the liquid gas analyzer.

2. The device of claim 1 wherein the volume of gas is atmospheric air.

3. The device of claim 1 wherein the gas-permeable tubing is made of a material having a relatively high gas permeability for oxygen or carbon dioxide in the range of about 0.6×10 −13 cm 3 cm cm −2 s −1 Pa −1 to about 10×10 −13 cm 3 cm cm −2 s −1 Pa −1 .

4. The device of claim 1 wherein the gas-permeable tubing is made of a material having an oxygen permeability selected from the group consisting of equal to or greater than about 0.6×10 −13 cm 3 cm cm −2 s −1 Pa −1 , equal to or greater than about 3×10 −13 cm 3 cm cm −2 s −1 Pa −1 , and equal to or greater than about 7×10 −13 cm 3 cm cm −2 s −1 Pa −1 .

5. The device of claim 1 wherein the gas-permeable tubing is made of a material having an oxygen permeability equal to about 3×10 −13 cm 3 cm cm −2 s −1 Pa −1 .

6. The device of claim 1 wherein the gas-permeable tubing is made of a material having an oxygen permeability equal to about 7×10 −13 cm 3 cm cm −2 s −1 Pa −1 .

7. The device of claim 1 wherein the gas-permeable tubing is made of a material having an oxygen permeability in the range of about 3×10 −13 cm 3 cm cm −2 s −1 Pa −1 to about 7×10 −13 cm 3 cm cm −2 s −1 Pa −1 .

8. The device of claim 1 wherein the gas-permeable tubing has a wall thickness in the range of about 0.011 inches to about 0.014 inches.

9. The device of claim 1 wherein the gas-permeable tubing has a wall thickness in the range of about 0.012 inches to about 0.013 inches.

10. The device of claim 1 wherein the gas-permeable tubing has a wall thickness sufficient to prevent wall collapse when the tubing is subjected to vacuum effect from a peristaltic pump while providing sufficient oxygen permeability to achieve solution oxygen equilibrium with atmospheric oxygen at the solution outlet for a solution passing through the tubing.

11. The device of claim 1 wherein the gas-permeable tubing is made of a material having a carbon dioxide permeability selected from the group consisting of equal to or greater than about 3×10 −13 cm 3 cm cm −2 s −1 Pa −1 , equal to or greater than about 7×10 −13 cm 3 cm cm −2 s −1 Pa −1 , and equal to or greater than about 10×10 −13 cm 3 cm cm −2 s −1 Pa −1 .

12. The device of claim 1 wherein the gas-permeable tubing is made of a material having a carbon dioxide permeability equal to about 3×10 −13 cm 3 cm cm −2 s −1 Pa −1 .

13. The device of claim 1 wherein the gas-permeable tubing is made of a material having a carbon dioxide permeability equal to about 7×10 −13 cm 3 cm cm −2 s −1 Pa −1 .

14. The device of claim 1 wherein the gas-permeable tubing is made of a material having a carbon dioxide permeability equal to about 10×10 −13 cm 3 cm cm −2 s −1 Pa −1 .

15. The device of claim 1 wherein the gas-permeable tubing is made of a material having a carbon dioxide permeability in the range of about 7×10 13 cm 3 cm cm −2 s −1 Pa −1 to about 10×10 −13 cm 3 cm cm −2 s −1 Pa −1 .

16. The device of claim 1 wherein the temperature-controlled, thermally-conductive mandrel has a thin-film heater disposed on an inside wall of the tubular mandrel.

17. The device of claim 1 wherein the gas-permeable tubing has a length in the range of about 35 inches to about 75 inches.

18. The device of claim 17 wherein the perfluoroalkoxy copolymer is tetrafluoroethylene-perfluoro(alkoxy vinyl ether).

19. The device of claim 17 wherein the ethylene-tetrafluoroethylene copolymer is polyethylenetetrafluoroethylene.

20. The device of claim 1 wherein the coil has predefined number of turns in the range of about 11 turns to about 23 turns.

21. The device of claim 1 wherein the gas-permeable tubing is made of a material selected from the group consisting of polytetrafluoroethylene, fluorinated ethylene propylene, perfluoroalkoxy copolymer, and ethylene-tetrafluoroethylene copolymer.

22. A gas-liquid equilibrium coil where the gas-liquid equilibrium coil provides, in real-time, a gas calibrating solution in a gas-liquid analyzer, the gas-liquid equilibrium coil comprising:

a temperature-controlled, thermally-conductive mandrel;

a coil of gas-permeable tubing wrapped around the mandrel, the gas-permeable tubing having an inlet and an outlet; and

temperature and gas means for controlling the environment around the gas-liquid equilibrium coil wherein a gas calibrating solution that exits the gas-liquid equilibrium coil has a predefined gas concentration defined by the temperature and gas of the temperature and means.

23. The equilibrium coil of claim 18 wherein the gas permeable tubing is made of a material having a relatively high gas permeability for oxygen or carbon dioxide in the range of about 3×10 −13 cm 3 cm cm −2 s −1 Pa −1 to about 10×10 −13 cm 3 cm cm −2 s −1 Pa −1 .