Groundwater velocity probe

• US 6,393,925 B1
• Filed: 03/17/2000
• Issued: 05/28/2002
• Est. Priority Date: 05/26/1999
• Status: Expired due to Fees

• Current Assignee: University of Waikato
• Original Assignee: University of Waikato
• Inventors: Devlin, John Frederick
• Primary Examiner(s): NOORI, MAX H
• Application Number:
  US09/528,172
• Time in Patent Office: 802 Days
• Field of Search: 73/861.07,861.05,861.95,866.5
• US Class Current: 73/861.05
• CPC Class Codes: G01F 1/7088 using electrically charged particles as tracers
• CPC Class Codes: G01P 5/20 using particles entrained by a fluid stream G01P5/22 takes precedence

Abstract

A groundwater velocity probe is provided comprising a surface with a first portion and a second portion, an injector for injecting a tracer proximate the first portion, a detector for detecting the tracer proximate the second portion, and a timer for measuring time elapsed between injecting the tracer and detecting the tracer. A method of measuring groundwater velocity in an aquifer is also provided comprising the steps of providing a groundwater velocity probe in an aquifer, the groundwater velocity probe having a surface with a first portion and a second portion, an injector for injecting a tracer having a characteristic property proximate the first portion, a detector for detecting the characteristic property of the tracer proximate the second portion, and a timer for measuring time elapsed between injecting the tracer and detecting the characteristic property of the tracer, injecting the tracer proximate the first portion, starting a timer in a datalogger, detecting the characteristic property of the tracer proximate the second portion, inputting an electrical signal representative of the characteristic property to the datalogger, and measuring time elapsed between injecting the tracer and detecting the characteristic property with the datalogger.

Claims

1. A groundwater velocity probe comprising a surface with a first portion and a second portion,

means for injecting a tracer proximate the first portion;

first means for detecting the tracer, said first means for detecting disposed at said second portion, and

means for measuring time elapsed between injecting the tracer and detecting the tracer.

2. The groundwater velocity probe as claimed in claim 1 wherein said surface is cylindrical.

3. The groundwater velocity probe as claimed in claim 2 wherein said cylindrical surface further comprises a third portion, and a second means for detecting the tracer is provided proximate the third portion, such that said means for injecting the tracer is disposed between said first means for detecting and said second means for detecting and such that said first means and said second means for detecting are oriented along different flowpaths originating from said means for injecting.

4. The groundwater velocity probe as claimed in claim 1 further comprising a pointed end for facilitating hammering of the probe into an aquifer.

5. The groundwater velocity probe as claimed in claim 1 wherein said first means for detecting the tracer includes a conductivity sensor.

6. The groundwater velocity probe as claimed in claim 1 wherein said tracer is injected along a first plane and said first means for detecting the tracer is disposed along substantially the same plane.

7. The groundwater velocity probe as claimed in claim 6 further comprising fist and second warning detectors disposed above and below said first means for detecting the tracer, the first and second warning detectors provided for sensing non-linear travel of the tracer.

8. The groundwater velocity probe as claimed in claim 7 wherein said first means for detect the tracer includes a conductivity sensor.

9. The groundwater velocity probe as claimed in claim 2 further comprising angular indicators for enabling rotation of the probe about its axis by a known angular displacement.

10. The groundwater velocity probe as claimed in claim 2 wherein said cylindrical surface comprises a third portion, and a second means for detecting the tracer is provided proximate the third portion, such that said first and said second means for detecting the tracer are oriented along a common flowpath originating from said means for injecting.

11. The groundwater velocity probe as claimed in claim 10 wherein each of said first and second means for detecting comprises a conductivity sensor.

12. The groundwater velocity probe as claimed in claim 1 further comprising a computing means for estimating groundwater velocity proximate said second portion.

15. The groundwater velocity probe as claimed in claim 1, further comprising a warning means for detecting the tracer, the warning means for detecting the tracer being disposed at a different plane than the first means for detecting the tracer.

16. The groundwater velocity probe as claimed in claim 15, wherein the warning means is disposed at a different vertical plane than the first means for detecting the tracer.

17. The groundwater velocity probe as claimed in claim 1, further comprising an angular indicator configured to facilitate rotation of the probe by a known angular displacement.

18. The groundwater velocity probe as claimed in claim 2, wherein the first means for detecting the tracer and the second means for detecting the tracer are disposed on a common plane.

19. The groundwater velocity probe as claimed in claim 18, wherein the first means and the second means are disposed on substantially the same vertical plane.

20. The groundwater velocity probe as claimed in claim 3, wherein the first means for detecting the tracer and are second means for detecting the tracer are oriented along directionally opposite flow paths.

21. The groundwater velocity probe as claimed in claim 10, wherein the first means and the second means for detecting the tracer are disposed on a substantially common plane.

22. The groundwater velocity probe as claimed in claim 21, wherein the first means and second means are disposed on substantially the same vertical plane.

13. A method of measuring groundwater velocity in an aquifer comprising the steps of:

providing a groundwater velocity probe in an aquifer, the groundwater velocity probe having a surface with a first portion and a second portion, means for injecting a tracer having a characteristic property proximate the first portion, means for detecting the characteristic property of the tracer proximate the second portion, and means for measuring time elapsed between injecting the tracer and detecting the characteristic property of the tracer;

injecting the tracer proximate the first portion;

starting a timer in a datalogger;

detecting the characteristic property of the tracer proximate the second portion;

inputting an electrical signal representative of the characteristic property to the datalogger, and

measuring time elapsed between injecting the tracer and detecting the characteristic property with the datalogger.

14. The method as claimed in claim 13 further comprising the step of inputting the time elapsed inflation into a computer for estimating velocity of the tracer proximate the second portion.