Method for measuring flow within an open tube

• US 6,779,396 B2
• Filed: 04/08/2002
• Issued: 08/24/2004
• Est. Priority Date: 04/08/2002
• Status: Expired due to Fees

• Current Assignee: Chemco Scientific Co., Ltd., Motonori Munesue, Takao Tsuda
• Original Assignee: Chemco Scientific Co., Ltd., Motonori Munesue, Takao Tsuda
• Inventors: Munesue, Motonori, Tsuda, Takao
• Primary Examiner(s): Lefkowitz, Edward
• Assistant Examiner(s): THOMPSON, JEWEL VERGIE
• Application Number:
  US10/119,131
• Publication Number:
  US 20030188575A1
• Time in Patent Office: 869 Days
• Field of Search: 732/042.7, 732/042.6, 732/042.3, 732/041.9, 732/042.5, 732/041.5
• US Class Current: 73/204.27
• CPC Class Codes: G01F 1/7084 using thermal detecting arrangements
• CPC Class Codes: G01N 2030/324 speed, flow rate
• CPC Class Codes: G01N 30/32 of pressure or speed G01N30/36 takes precedence

Abstract

A change in physical properties of a fluid within an open tube which is caused by heating an arbitrary portion in the open tube by heating means is detected by using a detector disposed with a predetermined spacing from the arbitrary portion, thereby measuring the flow in the open tube. The present invention provides a method for measuring flow within an open tube, in which a mechanical error and contamination of a passage do not occur, as a method for measuring flow within an open tube having a very small diameter provided for the separation analysis field and chemosynthesis field.

Claims

1. A method for measuring flow within an open tube having no insulating layer comprising:

heating an arbitrary portion in the open rube by heating means to make a change in physical properties of a fluid within the open tube;

providing an optical detector disposed with a predetermined spacing from the arbitrary portion; and

detecting the change by using the optical detector to measure the flow within the open tube.

2. The method according to claim 1, wherein a time difference between a time at which heating is started by the heating means and a time at which a signal is detected by the optical detector is measured.

3. The method according to claim 1, wherein the heating means is current-passing heating means or light-collecting heating means.

4. The method according to claim 1, wherein the heating by the heating means is performed by a gradient voltage.

5. The method according to claim 1, wherein the open tube is a capillary column for use in capillary electrophoresis, capillary liquid chromatography, and the like.

6. The method according to claim 1, wherein the open tube is a pre-column or a post column for use in gas chromatography, liquid chromatography, and the like.

7. The method according to claim 1, wherein the open tube is a catheter or a tube connected to a catheter for use in a system for automatically supplying chemical to an animal or a human being.

8. The method according to claim 1, wherein the open tube is a micropipet or a tube connected to a micropipet for use in study of life science and the like.

9. The method according to claim 1, wherein the change in physical properties of the fluid within the tube is a change in temperature or occurrence of bubbles.

10. The method according to claim 1, wherein the optical detector is constructed by a combination of an infrared LED and a photodiode.

21. The method according to claim 1, wherein the heating means is local heating performed by a current passing means comprising a single-wound coil.

11. A method for measuring flow within an open tube having no insulating layer comprising:

heating an arbitrary portion in the open tube by heating means to make a change in physical properties of a fluid within the open tube;

providing an optical detector disposed with a predetermined spacing from the arbitrary portion;

detecting the change by using the optical detector to measure the flow within the open tube; and

performing a computing process of the flow by a computer system to obtain a flow signal.

12. The method according to claim 11, wherein a time difference between a time at which heating is started by the heating means and a time at which a signal is detected by the optical detector is measured.

13. The method according to claim 11, wherein the heating means is current-passing heating means or light-collecting heating means.

14. The method according to claim 11, wherein the heating by the heating means is performed by a gradient voltage.

15. The method according to claim 11, wherein the open tube is a capillary column for use in capillary electrophoresis, capillary liquid chromatography, and the like.

16. The method according to claim 11, wherein the open tube is a pre-column or a post column for use in gas chromatography, liquid chromatography, and the like.

17. The method according to claim 11, wherein the open tube is a catheter or a tube connected to a catheter for use in a system for automatically supplying chemical to an animal or a human being.

18. The method according to claim 11, wherein the open tube is a micropipet or a tube connected to a micropipet for use in study of life science and the like.

19. The method according to claim 11, wherein the change in physical properties of the fluid within the tube is a change in temperature or occurrence of bubbles.

20. The method according to claim 11, wherein the optical detector is constructed by a combination of an infrared LED and a photodiode.

22. The method according to claim 11, wherein the heating means is local heating performed by a current passing means comprising a single-wound coil.

23. A method for measuring flow within an open tube comprising:

heating an arbitrary portion in the open tube by heating means to make a change in occurrence of bubbles of a fluid within the open tube;

providing a detector disposed with a predetermined spacing from the arbitrary portion; and

detecting the change by using the detector to measure the flow within the open tube.

24. The method according to claim 23, wherein a time difference between a time at which heating is started by the heating means and a time at which a signal is detected by the detector is measured.

25. The method according to claim 23, wherein the heating means is current-passing heating means or light-collecting heating means.

26. The method according to claim 23, wherein the heating by the heating means is performed by a gradient voltage.

27. The method according to claim 23, wherein the open tube is a capillary column for use in capillary electrophoresis, capillary liquid chromatography, and the like.

28. The method according to claim 23, wherein the open tube is a pre-column or a post column for use in gas chromatography, liquid chromatography, and the like.

29. The method according to claim 23, wherein the open tube is a catheter or a tube connected to a catheter for use in a system for automatically supplying chemical to an animal or a human being.

30. The method according to claim 23, wherein the open tube is a micropipet or a tube connected to a micropipet for use in study of life science and the like.

31. The method according to claim 23, wherein the detector is constructed by a combination of an infrared LED and a photodiode.

32. A method for measuring flow within an open tube comprising:

heating an arbitrary portion in the open tube by heating means to make a change in occurrence of bubbles of a fluid within the open tube;

providing a detector disposed with a predetermined spacing from the arbitrary portion; and

detecting the change by using the detector to measure the flow within the open tube; and

performing a computing process of the flow by a computer system to obtain a flow signal.

33. The method according to claim 32, wherein a time difference between a time at which heating is started by the heating means and a time at which a signal is detected by the detector is measured.

34. The method according to claim 32, wherein the heating means is current-passing heating means or light-collecting heating means.

35. The method according to claim 32, wherein the heating by the heating means is performed by a gradient voltage.

36. The method according to claim 32, wherein the open tube is a capillary column for use in capillary electrophoresis, capillary liquid chromatography, and the like.

37. The method according to claim 32, wherein the open tube is a pre-column or a post column for use in gas chromatography, liquid chromatography, and the like.

38. The method according to claim 32, wherein the open tube is a catheter or a tube connected to a catheter for use in a system for automatically supplying chemical to an animal or a human being.

39. The method according to claim 32, wherein the open tube is a micropipet or a tube connected to a micropipet for use in study of life science and the like.

40. The method according to claim 32, wherein the detector is constructed by a combination of an infrared LED and a photodiode.