Fault locating device, system and method

• US 5,804,822 A
• Filed: 12/09/1996
• Issued: 09/08/1998
• Est. Priority Date: 04/05/1995
• Status: Expired due to Fees

• Current Assignee: Brasscorp Limited
• Original Assignee: Brasscorp Limited
• Inventors: Goldfarb, Steven, Brass, Jack
• Primary Examiner(s): Berman, Jack I.
• Application Number:
  US08/755,851
• Time in Patent Office: 638 Days
• Field of Search: 250/302, 250/461.1, 250/504 H
• US Class Current: 250/302
• CPC Class Codes: G01M 3/20 using special tracer materials, e.g. dye, fluorescent material, radioactive material
• CPC Class Codes: G01N 21/91 using penetration of dyes, e.g. fluorescent ink

Abstract

A lamp system is for use in non-destructive testing to illuminate luminescent materials, such as fluorescent dyes. The lamp system has a control unit and a lamp. The lamp has a bulb and a filter. The bulb generates at least a first wavelength of invisible energy and the filter limits other visible wavelength light from the lamp. The lamp has a handle with a trigger. The control unit pulses the lamp on and off when the trigger is depressed. The luminescent material absorbs the first wavelength of energy and pulses in response when the lamp illuminates the material. The system can be AC or DC operated. It can be operated from an automotive battery.

Claims

1. A hand held lamp system for locating faults using luminescent material that absorbs ultraviolet electromagnetic radiation of a first wavelength, converts that energy and emits a second visible wavelength light, the system comprising:

a lamp for generating incident ultraviolet electromagnetic radiation of the first wavelength;

a bulb in the lamp, the bulb generating ultraviolet electromagnetic radiation, including radiation of the first wavelength and other wavelengths, and generating visible light; and

a control unit for repeatedly pulsing the bulb on and off at a pulse repetition frequency of substantially 0.5 Hz to less than 3 Hz, and with a bulb on duration which is long enough for the material to begin emitting the second wavelength, and with a bulb off duration which is long enough for the material to substantially stop emitting the second wavelength, the pulse repetition frequency, the bulb on duration and the bulb off duration all timed for the human eye to recognize the pulse of second wavelength light.

2. The lamp system of claim 1, wherein the lamp further comprises a filter for allowing electromagnetic radiation of the first wavelength to be emitted from the lamp while the filter limits visible light outside of the first wavelength from emitting from the lamp.

3. The lamp system of claim 1, wherein the first wavelength is approximately 360 nanometers.

4. The lamp system of claim 1, wherein the control unit pulses the bulb at a frequency between 0.5 and 3 Hz.

5. The lamp system of claim 1, wherein the lamp further comprises a handle for an operator to hold and aim the lamp, and a switch adjacent the handle for one handed operation of the lamp.

6. The lamp system according to claim 1, wherein the bulb comprises a halogen bulb.

7. The lamp system according to claim 1, wherein the bulb comprises a mercury vapour bulb, and wherein the control unit comprises (i) a strobing circuit for pulsing the bulb on and off, and (ii) a ballast.

8. The lamp system according to claim 1, wherein the bulb comprises an elongated fluorescent tube, and the lamp further comprises an elongated back casing for receiving the tube, the back casing being open on one side and coated internally with a reflective material.

9. The lamp system according to claim 8, wherein a shield encloses the back casing over the tube, and the shield is transmissive of the first wavelength radiation.

10. The lamp system according to claim 9, wherein the back casing and the shield extend into a housing for the control unit which is at least partially formed on a printed circuit hoard extending from the shield into the housing.

11. The lamp system according to claim 10, wherein the casing has a U-shaped profile and has opposing slots into which the shield is placed.

12. The lamp system of claim 10, wherein there is a duration between the bulb pulsing off and the bulb pulsing on, and the duration is greater than the time it takes for the material to cease emitting radiation after the bulb is pulsed off, to cause material on which the lamp is shone to emit radiation of the second wavelength pulsing on and off.

13. The lamp system of claim 12, wherein the material is phosphorescent.

14. The lamp system of claim 1, wherein the material is fluorescent.

15. A kit, comprising:

a hand held lamp system including;

a lamp for generating incident ultraviolet electromagnetic radiation of a first wavelength, and

a bulb in the lamp, the bulb generating ultraviolet electromagnetic radiation, including radiation of the first wavelength and other wavelengths, and generating visible light;

a control unit for repeatedly pulsing the bulb on and off at a pulse repetition frequency of substantially 0.5 Hz to less than 3 Hz, and with a bulb on duration which is long enough for the material to begin emitting the second wavelength, and with a bulb off duration which is long enough for the material to substantially stop emitting the second wavelength, the pulse repetition frequency, the bulb on duration and the bulb off duration all timed for the human eye to recognize the pulse of second wavelength light; and

a luminescent material that absorbs electromagnetic radiation of the first wavelength, converts that energy, and emits a second visible wavelength light to cause material on which the lamp is shone to emit radiation of the second wavelength pulsing on and off.

16. A method of locating luminescent material that absorbs electromagnetic energy of an ultraviolet electromagnetic radiation of a first wavelength, converts that energy and emits electromagnetic radiation of a substantially different visible second wavelength, the method comprising the steps of:

generating ultraviolet electromagnetic radiation, including radiation of the first wavelength and other wavelengths, and generating visible light from a bulb, and repeatedly pulsing the bulb on and off at a pulse repetition frequency of substantially 0.5 Hz to less than 3 Hz, and with a bulb on duration which is long enough for the material to begin emitting the second wavelength, and with a bulb off duration which is long enough for the material to substantially stop emitting the second wavelength, the pulse repetition frequency, the bulb on duration and the bulb off duration being timed for the human eye to recognize the pulse of second wavelength light;

while pulsing the bulb on, increasing the amount of ultraviolet electromagnetic radiation of the first wavelength emitting from the bulb relative to the amount of visible light emitting from the bulb by powering the bulb at a higher than nominal rating for the bulb to increase the temperature of the bulb over that which would result if the bulb was run at a nominal rating voltage for the bulb, and illuminating the material with the ultraviolet radiation of the first wavelength emitting from the bulb, to cause the material to fluoresce and pulse upon illumination.

17. The method of claim 16, wherein the ultraviolet electromagnetic radiation and visible light generated from the bulb are passed through a filter that allows the ultraviolet electromagnetic radiation of the first wavelength to pass and otherwise limits the amount of visible light passing through the filter.

18. A hand held lamp system for locating faults using luminescent material that absorbs ultraviolet electromagnetic radiation of a first wavelength, converts that energy and emits a second visible wavelength light, the system comprising:

a lamp for generating incident ultraviolet electromagnetic radiation of the first wavelength;

a bulb in the lamp, the bulb generating ultraviolet electromagnetic radiation, including radiation of the first wavelength and other wavelengths, and generating visible light; and

a control unit for, in normal operation, repeatedly pulsing the bulb on and off, the control unit increasing the amount of ultraviolet electromagnetic radiation of the first wavelength emitting from the bulb relative to the amount of visible light emitting from the bulb by repeatedly powering the bulb at a higher electrical rating than the nominal electrical rating for the bulb to increase the temperature of the bulb over that which would result if the bulb was run at the nominal rating for the bulb, to cause material on which the lamp is shone to emit radiation of the second wavelength pulsing on and off, the control unit pulsing the bulb with a bulb-on duration, a bulb-off duration, and a pulse frequency which are all timed to cause each pulse repetition of the second wavelength to be visible to the unaided human eye.

19. A lamp system according to claim 18, wherein said bulb comprises a tungsten filament bulb.

20. A system according to claim 18, wherein the electrical rating comprises a voltage.

21. A kit, comprising:

a hand held lamp system including;

a lamp for generating incident ultraviolet electromagnetic radiation of a first wavelength, and

a bulb in the lamp, the bulb generating ultraviolet electromagnetic radiation, including radiation of the first wavelength and other wavelengths, and generating visible light;

a control unit for, in normal operation, repeatedly pulsing the bulb on and off, the control unit increasing the amount of ultraviolet electromagnetic radiation of the first wavelength emitting from the bulb relative to the amount of visible light emitting from the bulb by repeatedly powering the bulb at an electrical rating which is higher than the nominal electric rating for the bulb to increase the temperature of the bulb over that which would result if the bulb was powered at the nominal electrical rating for the bulb, the control unit pulsing the bulb with a bulb-on duration, a bulb-off duration, and a pulse frequency which are all timed to cause each pulse repetition of the second wavelength to be visible to the unaided human eye; and

a luminescent material that absorbs electromagnetic radiation of the first wavelength, converts that energy, and emits a second visible wavelength light to cause material on which the lamp is shone to emit radiation of the second wavelength pulsing on and off.

22. A kit according to claim 21, wherein said bulb comprises a tungsten filament bulb.

23. A kit according to claim 21, wherein the electrical rating comprises a voltage.

24. A method of locating luminescent material that absorbs electromagnetic energy of an ultraviolet electromagnetic radiation of a first wavelength, converts that energy and emits electromagnetic radiation of a substantially different visible second wavelength, the method comprising the steps of:

generating ultraviolet electromagnetic radiation, including radiation of the first wavelength and other wavelengths, and generating visible light from a bulb, and, in normal operation, repeatedly pulsing the bulb on and off;

while pulsing the bulb on, increasing the amount of ultraviolet electromagnetic radiation of the first wavelength emitting from the bulb relative to the amount of visible light emitting from the bulb by powering the bulb at an electrical rating which is higher than the nominal electric rating for the bulb to increase the temperature of the bulb over that which would result if the bulb was run at a nominal electrical rating for the bulb, and illuminating the material with the ultraviolet radiation of the first wavelength emitting from the bulb, to cause the material to fluoresce and pulse upon illumination, the control unit pulsing the bulb with a bulb-on duration, a bulb-off duration, and a pulse frequency which are all timed to cause each pulse repetition of the second wavelength to be visible to the unaided human eye.

25. A method according to claim 24, wherein said step of generating ultraviolet radiation includes the step of generating the radiation of the first wavelength and other wavelengths and the visible light with a tungsten filament bulb.

26. A method according to claim 24, wherein the electrical rating comprises a voltage.

27. A hand held lamp system for locating faults using luminescent material that absorbs ultraviolet electromagnetic radiation of a first wavelength, converts that energy and emits a second visible wavelength light, the system comprising:

hand-held means for an operator to grip said lamp system;

a lamp for generating incident ultraviolet electromagnetic radiation of the first wavelength;

a tungsten filament bulb in the lamp, the tungsten filament bulb generating ultraviolet electromagnetic radiation, including radiation of the first wavelength and other wavelengths, and generating visible light; and

a control unit for, in normal operation, repeatedly pulsing the tungsten filament bulb on and off to cause (i) the luminescent material to convert the absorbed ultraviolet radiation to pulses of the second wavelength light, and (ii) the converted pulses of second wavelength light to be recognizable by a human eye as pulses, the control unit pulsing the bulb with a bulb-on duration, a bulb-off duration, and a pulse frequency which are all timed to cause each pulse repetition of the second wavelength to be visible to the unaided human eye.