Claims
- 1. A pH sensor system comprising:
a housing having at least one transparent surface; a light sensing circuitry enclosed within the housing; and, a chromatic pH sensitive material overlaying at least a portion of the transparent surface having the characteristic of becoming saturated when an ambient pH level reaches a predetermined level, wherein the light sensing circuitry detects a different intensity of incident light when the chromatic pH sensitive material is saturated than when the chromatic pH sensitive material is not saturated.
- 2. The pH sensor system of claim 1 wherein the housing is a material selected from the group consisting of ceramic material, plastic material, nylon, concrete, epoxy and combinations thereof.
- 3. The pH sensor system of claim 1 wherein the transparent surface comprises glass or sapphire.
- 4. The pH sensor system of claim 1 wherein the pH sensitive material comprises an inert material and a pH indicator.
- 5. The pH sensor system of claim 4 wherein the inert material is cellulose, cellulose acetate or a silica-based gel.
- 6. The pH sensor system of claim 4 wherein the pH indicator is trinitrobenzene sulfonic acid.
- 7. The pH sensor system of claim 4 wherein the pH sensitive material further comprises a catalyst selected from the group consisting of sodium hydroxide, potassium hydroxide, water and mixtures thereof.
- 8. The pH sensor system of claim 1 wherein the pH sensitive material comprises an inert material selected from the group consisting of cellulose, cellulose acetate or a silica-based gel, trinitrobenzene sulfonic acid and a catalyst selected from the group consisting of sodium hydroxide, potassium hydroxide, water and mixtures thereof.
- 9. The pH sensor system of claim 1 wherein the light sensing circuitry comprises a light emitting diode capable of emitting light and a photo-detector capable of detecting incident light reflected by the transparent surface.
- 10. The pH sensor system of claim 1 wherein the light sensing circuitry is powered by a power source.
- 11. The pH sensor system of claim 10 wherein the power source is inside or outside the housing.
- 12. The pH sensor system of claim 11 wherein the power source is a battery or capacitor.
- 13. The pH sensor system of claim 9 wherein the light sensing circuitry further comprises a voltage meter and A/D converter.
- 14. The pH sensor system of claim 9 wherein the light sensing circuitry further comprises a lock-in amplifier and A/D converter.
- 15. The pH sensor system of claim 1 wherein the ambient pH level is from about 12 to about 14 and the predetermined pH level is less than or equal to about 12.
- 16. The pH sensor system of claim 8 wherein the ambient pH level is from about 12 to about 14 and the predetermined pH level is less than or equal to about 12.
- 17. A method for monitoring the pH level of a medium comprising the steps of:
providing a pH sensor system comprising a housing having at least one transparent surface; a light sensing circuitry enclosed within the housing; and, a chromatic pH sensitive material overlaying at least a portion of the transparent surface having the characteristic of becoming saturated when an ambient pH level reaches a predetermined level such that the light sensing circuitry detects a different intensity of incident light when the chromatic pH sensitive material is saturated than when the chromatic pH sensitive material is not saturated; and, embedding the pH sensor system within the medium to be monitored.
- 18. The method of claim 17 wherein the medium possesses a pH level from about 12 to about 14.
- 19. The method of claim 17 wherein the medium is selected from the group consisting of concrete, soil, storage tanks containing chemical reagents or biological mediums.
- 20. The method of claim 19 wherein the chemical reagents in the storage tank are an alkali medium.
- 21. The method of claim 20 wherein the alkali medium is selected from the group consisting of potassium hydroxide, sodium hydroxide and mixtures thereof.
- 22. The method of claim 17 wherein the housing of the pH sensor system is a material selected from the group consisting of ceramic material, plastic material, nylon, concrete, epoxy and combinations thereof.
- 23. The method of claim 17 wherein the transparent surface of the housing comprises glass or sapphire.
- 24. The method of claim 17 wherein the light sensing circuitry is powered by a power source.
- 25. The method of claim 24 wherein the power source is inside or outside the housing.
- 26. The method of claim 24 wherein the power source is a battery or capacitor.
- 27. The method of claim 17 wherein the pH sensitive material comprises an inert material and a pH indicator.
- 28. The method of claim 27 wherein the inert material is cellulose, cellulose acetate or a silica-based gel.
- 29. The method of claim 27 wherein the pH indicator is trinitrobenzene sulfonic acid.
- 30. The method of claim 27 wherein the pH sensitive material further comprises a catalyst selected from the group consisting of sodium hydroxide, potassium hydroxide, water and mixtures thereof.
- 31. The method of claim 17 wherein the pH sensitive material comprises an inert material selected from the group consisting of cellulose, cellulose acetate or a silica-based gel, trinitrobenzene sulfonic acid and a catalyst selected from the group consisting of sodium hydroxide, potassium hydroxide, water and mixtures thereof.
- 32. The method of claim 17 wherein the light sensing circuitry comprises a light emitting diode capable of emitting light and a photo-detector capable of detecting incident light reflected by the transparent surface.
- 33. The method of claim 32 wherein the light sensing circuitry further comprises a voltage meter and A/D converter.
- 34. The method of claim 32 wherein the light sensing circuitry further comprises a lock-in amplifier and A/D converter.
- 35. The method of claim 17 wherein the ambient pH level is from about 12 to about 14 and the predetermined pH level is less than or equal to about 12.
- 36. The method of claim 24 wherein the ambient pH level is from about 12 to about 14 and the predetermined pH level is less than or equal to about 12.
- 37. A pH sensor system comprising:
a housing having at least one transparent surface; a light sensing circuitry enclosed within the housing; and, a chromatic pH sensitive material comprising an inert material and a pH indicator capable of indicating a pH of less than or equal to about 12 and overlaying at least a portion of the transparent surface having the characteristic of becoming saturated when an ambient pH level reaches a predetermined level of less than or equal to about 12, wherein the light sensing circuitry detects a different intensity of incident light when the chromatic pH sensitive material is saturated than when the chromatic pH sensitive material is not saturated.
- 38. The pH sensor system of claim 37 wherein the housing is a material selected from the group consisting of ceramic material, plastic material, nylon, concrete, epoxy and combinations thereof and the transparent surface comprises glass or sapphire.
- 39. The pH sensor system of claim 37 wherein the pH sensitive material comprises an inert material selected from the group consisting of cellulose, cellulose acetate or a silica-based gel, trinitrobenzene sulfonic acid and a catalyst selected from the group consisting of sodium hydroxide, potassium hydroxide, water and mixtures thereof.
- 40. The pH sensor system of claim 37 wherein the light sensing circuitry comprises a light emitting diode capable of emitting light and a photo-detector capable of detecting incident light reflected by the transparent surface.
- 41. The pH sensor system of claim 37 wherein the light sensing circuitry is powered by a power source.
- 42. The pH sensor system of claim 41 wherein the power source is inside or outside the housing.
- 43. The pH sensor system of claim 41 wherein the power source is a battery or capacitor.
- 44. The pH sensor system of claim 40 wherein the light sensing circuitry further comprises a voltage meter and A/D converter.
- 45. The pH sensor system of claim 40 wherein the light sensing circuitry further comprises a lock-in amplifier and A/D converter.
- 46. The pH sensor system of claim 37 wherein the ambient pH level is from about 12 to about 14.
- 47. A method for monitoring the pH level of a medium comprising the steps of:
providing the pH sensor system of claim 37; and, embedding the pH sensor system within a medium selected from the group consisting of concrete, soil and storage tanks containing a chemical reagent.
- 48. The method of claim 47 wherein the housing is a material selected from the group consisting of ceramic material, plastic material, nylon, concrete, epoxy and combinations thereof and the transparent surface comprises glass or sapphire.
- 49. The method of claim 47 wherein the pH sensitive material comprises an inert material selected from the group consisting of cellulose, cellulose acetate or a silica-based gel, trinitrobenzene sulfonic acid and a catalyst selected from the group consisting of sodium hydroxide, potassium hydroxide, water and mixtures thereof.
- 50. The method of claim 47 wherein the light sensing circuitry comprises a light emitting diode capable of emitting light and a photo-detector capable of detecting incident light reflected by the transparent surface.
- 51. The method of claim 47 wherein the light sensitive circuitry is powered by a power source.
- 52. The method of claim 51 wherein the power source is inside or outside the housing.
- 53. The method of claim 51 wherein the power source is a battery or capacitor.
- 54. The method of claim 50 wherein the light sensing circuitry further comprises a voltage meter and A/D converter.
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Application No. 60/210,547, filed Jun. 9, 2000, entitled “Embeddable Solid State Sensor for pH Monitoring in Concrete and Other Mediums” of Phillips et al. The contents of the aforesaid U.S. Provisional Application No. 60/210,547 are hereby incorporated by reference.
PCT Information
Filing Document |
Filing Date |
Country |
Kind |
PCT/US01/18694 |
6/8/2001 |
WO |
|