GB2500281A

GB2500281A - Magnetic particle inspection device

Info

Publication number: GB2500281A
Application number: GB1212162.0A
Authority: GB
Inventors: Jonathan Roger Max Johnson
Original assignee: Johnson and Allen Ltd
Current assignee: Johnson and Allen Ltd
Priority date: 2012-03-15
Filing date: 2012-07-09
Publication date: 2013-09-18
Also published as: GB201204569D0; GB201212162D0

Abstract

A magnetic particle inspection (MPI) device 10 comprises a light source 16 for illuminating an object under test, a magnetic particle applicator 14 for selectively applying magnetic particles to the object, and a handle 12 for manual positioning of the light source and applicator at a desired location relative to the object. A flowpath is provided for directing a flow of magnetic fluid within the device which comprises supply channel 36 for receiving fluid from a supply and conveying it to the applicator, and a bypass channel 38 for returning fluid to the supply. The light source may be a UV light source 28 and the device includes a mount on the handle 12 for mounting the source 28. The device may include means to connect to a magnetization source and actuators to switch the particle supply and the magnetization source.

Description

Magnetic Particle Inspection Device

Technical Field

The present invention relates to a magnetic particle inspection device and a method of inspecting a component using a hand held MPI device.

Background

Magnetic particle inspection is a non-destructive testing technique for detecting surface and sub-surface defects or discontinuities in felToelectric materials. To inspect a component using MPI, magnetic particles are applied to the suiface of the component and the component is magnetised using either direct or indirect magnetisation. Relative movement or congregation of the magnetic particles is observed, in order to evaluate the integrity of the component under test.

The magnetic particles are often iron oxide filings. These can be applied dry or in a suspension of oil or water. The iron oxide flings are sometimes dyed to make detection easier.

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Evaluation of the component may be assisted using a light source to illuminate the magnetic particles. e.g. using an ulira violet (UV) light source. Typically. UV lights include a mercury arc bulb. However, the mercury arc is prone to being drawn towards the magnetic field around the component, which can sometimes cause the arc to extinguish. An operator is then required to wait approximately 15 minutes for the light to cool down and the arc to re-ignite, making the inspection process unduly time-consuming.

Summary of invention

The present invention seeks to alleviate proNems associated with magnetic partide inspection equipment of the pnor art.

According to a first aspect of the present invention, there is provided a magnetic particle inspection (MPI) device comprising:

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a light source for illuminating an object or component under test; a magnetic particle applicator for selectively applying magnetic particles to an object or component under test; and a handle for manual positioning of the light source and applicator at a desired location relative to an object or component under test.

Advantageously, the MPI device enables one-handed operation for applying the magnetic particles and for inspecting a surface of a component under test during or after application of the magnetic particles. This simplifies the magnetic particle inspection process. The magnetic particles may be suspended in a fluid, often refelTed to as a magnetic fluid. The fluid may comprise oil or water.

The device may be configured for one-handed operation for applying the magnetic fluid and for inspecting a surface of a component under test during or after application of the magnetic fluid using said light source. For example, the light source, the magnetic particale applicator and the handle may be integrated into a single hand-held component.

In exemplary embodiments, the MPI device may comprise a connection to a magnetisation source. The MPI device may comprise an actuator positioned on the handle for activating and deactivating the magnetisation source. Advantageously, providing an actuator on the handle of the device permits an operator to activate the magnetic field as well as apply magnetic particles and inspect a component using a single hand. Single handed operation enables an operator to better concentrate on a component under inspection because there is no need for an operator to look away and become distracted from a component under inspection, e.g. to press a switch or button in a location other than the handle. It can also mean that an operator does not waste time looking for inki hoses, or conventional foot switches, and as such removes the need (and the time taken) for an operator to re-focus on a test area. Thus, inspection integrity can be improved and the time taken to inspect a component can be reduced.

The actuator positioned on the handle may be a button, or any suitable actuation means.

The MPI device may comprise an indicator to indicate when the magnetisation source is activated or deactivated. Such an indicator reduces the need for an operator to look away from a component under inspection, which eases the inspection process. For example, the indicator may be provided at a position corresponding to a line of sight of an operator. The indicator may be a light that is lit when the magnetisation source is activated. The indicator may show that the magnetisation source is activated when a current is flowing either through a component (i.e. direct magnetisation) or through an outside source (i.e. indirect magnetisation) provided to magnetise the component.

The device may be configured to be programmable for an inspection routine, including the steps of magnetising a component. applying magnetic particles to a component and inspecting a component. The MPI device may comprise an actuator, for example a button or toggle for selecting andlor activating an inspection program.

For example, an operator may be able to scroll through programs to select a desired program, position a shde button on a desired program or press a button to activate a program. The button or toggle may be positioned on the handle.

In exemplary embodiments, the light source is an Ultra Violet (UV) light source. For example, the fight source may be a UV light emitting diode (LED). The UV LED may be a high intensity UV LED. Unlike the mercury arc lamps of the prior art, a UV LED can be held within a strong magnetic field without the magnetic field affecting it.

As such, an UV LED does not experience the problem of the light extinguishing during the testing process. and therefore there is not the problem of an operator being required to wait approximately 15 minutes for the light to cool and be used again during the testing process. Therefore, the efficiency of the magnetic particle inspection process is improved.

In exemplary embodiments, the device includes a fiowpath for directing a flow of magnetic fluid within the device, e.g. a fluid comprising water or oil base with magnetic particles suspended therein. The magnetic particles may be iron oxide particles. The magnetic particles may be dyed or coated with a florescent dye. The magnetic particles may comprise a magnetic powder, for example an iron oxide powder.

In exemplary embodiments, the fiowpath may comprise a supply channel for receiving fluid from a remote supply and conveying said fluid to the applicator. The supply channel may be located within the handle of the device.

In exemplary embodiments, the device is configured for selectively supplying a flow of magnetic fluid to the applicator. For example, a supply switch having an open and a closed position may be provided within the supply channel for selectively interrupting a flow of fluid to the applicator.

The MPI device may comprise an actuator, e.g. a button for actuating the supply switch. The button may be removable from the MPI device. Removal of the button can permit access to the supply switch for maintenance work, for example, replacing one or more seals associated with the supply switch.

A groove may be provided in the MPI device extending from a region where the button is located. The groove may direct any magnetic fluid that may leak from the device to a desired location. For example, the groove may extend along the handle of the device such that, when not in use, if the N4P1 device, in particular the handle of the MPI device, is mounted above a collection tank, the fluid can be directed to the collection tank.

The MPI device may comprise an actuator for actuating the supply switch and an actuator for actuating and deactivating a magnetisation source, and both actuators may be positioned towards a front of the handle, but one of the actuators may be provided towards one side of the handle and the other actuator may be provided towards an opposite side of the handle. For example, the handle may configured for a user to grip the handle using a power grip and one button may be positioned such that a user's index finger can actuate one of the buttons without substantially releasing the power grip.

In exemplary embodiments, the flowpath further includes a bypass channel for returning fluid supplied to the device (e.g. if the supply switch is in a position to prevent the fluid being conveyed to the applicator). The bypass channel may form part of a circulation system between the device and the remote source of fluid, which has the advantage of keeping the fluid fresh. For example, where the fluid is a suspension of magnetic particles in a water or oil base, the circulation system reduces settlement of the particles in the oil or water base which means the correct concentration of magnetic fluid is delivered to a component. The circulation system also reduces the likelihood of associated clogging/blockages within the flowpath of the device.

In exemplary embodiments, the by-pass channel extends at least partly within the handle of the device. Advantageously this means that the length of the supply path between a junction with the bypass channel and the applicator can be reduced. Such an arrangement means that there is no need for the supply channel to be bled before use, because the colTect concentration of magnetic fluid can be supplied a'most, if not, 1 5 from first use.

In exemplary embodiments, the device includes a supply conduit extending into the handle, for conveying fluid to the device from a remote source. The conduit is arranged in communication with the supply channel and the bypass channel, so that fluid from the remote source may flow along the supply channel and the bypass channel. If flow within the supply channel is interrupted (e.g. via operation of the supply switch), all of the flow will continue along the bypass channel, e.g. for return to the remote source. In exempbry embodiments, the device includes a conduit extending from the handle and in communication with the bypass channel, e.g. for returning fluid to the remote source.

In exemplary embodiments, a valve is provided in the bypass channel, for adjusting the pressure of fluid within the device, and thereby controlling or adjusting the pressure of the magnetic fluid flowing towards the applicator. This enables an operator to adjust the flow rate of fluid exiting the applicator depending on the shape and/or size of a component to be inspected.

The valve may be a restrictor valve. The restrictor valve may be preset before use by an operator.

The applicator may comprise a nozzle. The nozzle may be removably mounted to the MPT device such that the nozzle is interchangeable. for example. the nozzle may be changed to adjust the flow rate and/or the spray pattern. The spray pattern may, for example, be a circubr spray pattern or a flat curtain spray.

According to a second aspect of the invention there is provided a magnetic particle inspection (MPI) device comprising: a mount for a light source for illuminating an object or component under test; a magnetic particle applicator for selectively applying magnetic particles to an object or component under test; and a handle for manual positioning of the light source and applicator at a IS desired location rdative to an object or component under test; and a flowpath for directing a flow of magnetic fluid within the device; wherein the flowpath comprises a supply channel for receiving fluid from a remote supply and conveying said fluid to the applicator, and a bypass channel for returning fluid supplied to the device.

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The mount may comprise a concave surface positioned at an end of the handle.

According to a third aspect of the invention there is provided a magnetic partide inspection (MPI) device comprising: a mount for a light source and/or a light source for illuminating an object or component under test; a magnetic particle applicator for selectively applying magnetic particles to an object or component under test; a handle for manual positioning of the light source and applicator at a desired location relative to an object or component under test; a connector for connection to a magnetisation source; a first actuator for actuating a supply of magnetic particles to the magnetic particle applicator; and a second actuator for actuating a magnetisation source for magnetising a component for inspection.

Optional features described with reference to the first and/or second aspect may be applied to the MPI device for the third aspect.

According to a fourth aspect of the invention there is provided an MPI apparatus including a reservoir of magnetic fluid, and a device of the first, second, or third aspect wherein the device is arranged in flow communication with the magnetic fluid in the reservoir.

A pump may be included for pumping fluid from the reservoir to the device. An agitator may be provided within the reservoir, for agitating the fluid and reducing settlement within the fluid.

In exemplary embodiments, the apparatus is configured to aflow fluid to return to the reservoir from the device (e.g. via the bypass channel). Fluid returning to the reservoir may be cooled, e.g. by passing over a cooled surface or through a heat exchanger, en route between the device and the reservoir.

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According to a fifth aspect of the invention, there is provided a bench inspection unit comprising the MPI device according to the first or second aspect, or the MPI apparatus according to the second aspect.

According to a sixth aspect of the invention, there is provided a method of MPI inspection, the method comprising the steps of: applying a magnetic fluid to a component using a hand held MPI device; using said hand held MPI device to illuminate said component and locate surface defects using an ultra violet light source; wherein the hand held MPI device is connected to a tank for stonng said magnetic fluid, and circulation system is used to selectively circubte said magnetic fluid between the device and the tank.

The hand held MPI device may be the MPI device of the first or the second aspect of the invention.

Description of the drawings

Embodiments of the invention will now be described with reference to the drawings in which: Figure 1 shows a perspective view of a magnetic particle inspection (MPI) device according to an embodiment of the invention; Figure 2 shows a schematic of a re-circulation system of the MPI device of Figure 1; Figure 3 shows an inspection bench according to an embodiment of the invention; Figure 4 shows a rear view of a magnetic particle inspection (MPI) device according to a further embodiment of the invention; Figure 5 shows a front view of the MPI device of Figure 4; Figure 6 shows a side view of the MPI device of Figure 4; IS Figure 7 shows a perspective view of the MPI device of Figure 4; Figure 8 shows another perspective view of the MPI device of Figure 4; and Figure 9 shows a rear view a MPI device according to yet a further embodiment of the invention.

Detailed description

Referring to Figures 1 and 2, a magnetic particle inspection (MPI) device according to an embodiment of the invention is indicated generally at 10. The device 10 includes a light source 16 for illuminating an object or component under test, a magnetic partide applicator 14 for selectively applying magnetic particles to an object or component under test. and a handle 12 for manual positioning of the light source and applicator at a desired location relative to an object or component under test.

In this embodiment, the handle is an elongate component dimensioned to fit in a hand, e.g. so that the handle is positioned between the palm and the fingers, and the fingers and the thumb of the hand wrap around the handle -known in ergonomics as a power grip'. The handle has a surface formation 18 induding grooves, three in this embodiment, for supporting a user's fingers, so as to improve the comfort for a user when gripping the handle. In alternative embodiments, the handle may be of any other suitable shape or configuration for hand-held use.

In this embodiment, the light source is an ultra violet (IJV) light source 16 having a main body, similar in construction to a torch, mounted at an upper end of the handle 12.

In this embodiment, the applicator 14 is positioned below the main body 28 of the UV light source 16, extending from the handle 12, at a position adjacent the upper end of the handle 12.

The applicator 14 includes a flexible arm 20 extending transversely from the handle 12 and having a head 22 at a distal end of the arm 20. In this embodiment the head 22 includes a brush 24, for use in painting of a surface of a component with a fluid containing magnetic particles. The arm 20 takes the form of a conduit for supp'ying magnetic fluid to the head 22, via a nozzle 26 positioned at the end of the arm (as can be seen in Figure 2, but obscured from view by the brush 24 in Figure 1). Fluid exiting the nozzle 26 is dispersed into the brush 24 of the head 22 of the applicator 14.

The flexiNe nature of the channel 20 enables the applicator 14 to move as the fluid is applied to the surface of a component, which eases the application of the fluid.

In alternative embodiments the head 22 is mounted to the arm 20 or the aim is mounted to the handle 12 in by a removaNe mount, such that the head and/or head and arm are interchangeably mounted. Such an arrangement permits the selection of the type of nozzle, for example a nozzle providing a round spray path, a nozzle providing a curtain spray and/or a nozzle varying the flow rate. Such nozzles may be used with or without brush 24.

The UV light source 16 in this embodiment is a high intensity UV light emitting diode (LED). The UV LED and associated electronics are encased in the body 28. In this embodiment, the body 28 is cylindrical and extends longitudinally in a direction transverse to the handle 12 of the device. A lens 30 is positioned at the end of the body 28. The lens may be planar or may have any other suitable shape so formed as to appropriately direct the light from the LED to the surface of the component to be inspected. The opposite end of the body 28 is closed by a cap 32, e.g. attached to the body 28 by a screw thread or a push fit, so as to fully enclose the LED and associated electronics in the body 28. In this embodiment, the cap 32 is removable for maintenance. In other embodiments, the cap may not be removable, e.g. may be integrally formed as part of the body 28.

Power is supplied to the LED using a power lead 34 which extends from main body 28 through the handle and out of the lower end of the handle, for connection to an external power source. hi alternative embodiments, power may be supplied to the LED using a battery mounted within the handle 12 or body 28. The battery may be rechargeable.

Two flexible fluid conduits 36, 38 are coupled to the lower end of the handle 12, and form part of a flow path for magnetic fluid from an external source. Their respective parts of the flow path are indicated at 42 and 44 in figure 2.

The supply of fluid to the applicator 12 will now be described in detail with reference to Figure 2.

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A tank 54 is provided externally of the device 10 for containing a reservoir of magnetic fluid 54, which in this embodiment is a fluorescent magnetic ink. In this embodiment the ink is a water based ink made from a concentrate, for example NeoAstra FCW or DGCW concentrate manufactured by the applicants, desirably diluted at a ratio of 50:1 with water. The ink may contain agents such as a wetting agent, rust inhibitor and anti-foam. In alternative embodiments, a hydrocarbon based concentrate diluted using a suitable canier fluid, for example at a 50:1 ratio. may be used. An example of such a concentrate is NeoAstra FC which is manufactured by the applicants.

A pump 58 extends into reservoir 56. The pump 58 is configured to agitate the fluid of the reservoir 56, and also to pump the fluid from the tank 54 to the flow channel 42.

The flow of the fluid from the tank 54 through the flow channel 42 and towards the handle 12 is indicated by 1TOWS 50 and 52.

At a point after the flow channel 42 enters the handle 12, the flow channel 42 reaches a junction 45 where the flow channel 42 adjoins a supply channel 46 within the handle 12. Supply channel 46 extends from the junction 45 to an input end of the applicator 14. A switch 48 is positioned in the handle 12, and is operable for interrupting fluid flow along the supply channel 46, by movement from an open (or off') position to a closed (or on') position, e.g. by actuating a button 40 positioned on the handle 12 of the MPI device 10.

A by-pass channel 44 is provided within the handle 12, in communication with the flow channel 42 via the junction 45. The bypass channel 44 extends between the junction 45 and the tank 54, such that the flow channel 42 and the bypass channel 44 can cooperate to provide a loop for circulating a flow of fluid from the tank 54.

A valve 60 is positioned along the bypass channel 44. The valve 60 can be used to restrict flow through the bypass channel by varying degrees to alter the pressure of the fluid upstream of the valve 60, e.g. within the upper part of the bypass channel 44, the supply channel 46 (when fluid is travelling in said supply channel) and the flow channel 42. The valve may be a restrictor valve, for example a modified ball valve, a gate valve, a butterfly valve or a pneumatically actuated globe or diaphragm valve.

As will be described later, altering the pressure of the fluid in the supply channel can be used to adjust the spray pressure of fluid arriving at the applicator 14 and exiting through the nozzle 26.

Downstream of the valve 60, the bypass channel 44 has an outlet positioned adjacent a surface 62 of the tank 54, such that circulated fluid exits the bypass channel 44 and flows onto the surface 62. The surface 62 is cooled, to reduce the temperature of the fluid flowing back to the tank (i.e. by convection). In alternative embodiments, the surface 62 may form part of some other component, for example a heat exchanger. for receiving and cooling fluid from the outlet of the bypass channel 44.

The flow of fluid from the tank 54 when the switch 48 is in the open position is indicated by the broken arrow 52. When the switch is in the open position, fluid is pumped from the tank 54 into the flow channel 42. Since the switch 48 is open and therefore preventing flow of fluid to the applicator 14, a significant proportion of the fluid flows directly to the bypass channel 44 and back into the tank (via cooled surface 62). This flow of fluid is continuous whilst the pump is switched on.

The principal flow of fluid from the tank 54 when the switch 48 is in the closed position is indicated by the solid arrow 50. In the closed position, fluid is permitted to flow along the supply channel 46 to the applicator 14, for application on the surface of a component.

When the switch is in the closed position, the valve 60 can be used to adjust the rate of flow along the bypass channel 44. This in turn alters the pressure of the fluid in the supply channel 46 when it arrives at the nozzle 26 of the applicator 14.

Referring now to Figure 3, an inspection bench 64 may be used for inspecting a component. The inspection bench 64 is of a type known in the art and has a head 66 and a tail 68 for magnetising a component to be inspected. The component to be inspected is positionable in a region 72 between the head and the tail. A control panel is provided to permit an operator to control the magnetising of the component.

The tank 54 of the described embodiment may be mounted on or beneath the bench.

To inspect a component, the component is positioned in the region 72 between the head 66 and tail 68. The controls 70 are then operated such that the component is magnetised. During magnetisation, and up to the end of the magnetising process, the component is painted with a magnetic fluid, for example a flourescent magnetic ink (of the type previously described). To paint the component, an operator uses the MPI device 10, and closes the switch 48 by pressing the button 40 on the handle 12 of the device. When the switch 48 is closed, fluid from the tank flows along the channel 42, through supply channel 40, and to the applicator 14; flowing along the channel 20 of the applicator and exiting at the nozzle 26. The brush end 24 of the applicator permits the user to paint the ink onto the component to be inspected. Once the component is fully magnetised, the operator may stop painting the component with the ink. The component is now ready for inspection.

To stop the ink flowing to the applicator 14 the operator opens the switch 48 by pressing button 40. When the switch 48 is open, the ink circulates through the flow channel 42, the bypass channel 44 and the tank 54. This keeps the ink fresh and ready for use when needed, avoiding undesired settlement of the magnetic particles.

Concurrently or after interruption of the flow, the operator can use the UV LED light 16 of the MPI device 10 to inspect the component under test.

Advantageously, the MPI device provides a single source for the light and magnetic fluid, meaning that the MPI inspection can be carried out single-handedly using a single device; the operator does not need to change equipment to perform inspection of the component and can apply magnetic fluid to the surface and inspect the surface in a simple, single handed operation.

The UV LED light can be switched on (e.g. using a separate switch -not illustrated -on the handle 12 or body 28) prior to, during, or after application of the magnetic fluid.

The UV LED light means it is not affected by the magnetic field around the component under test (as would be the case with a UV mercury arc bulb), and accordingly is not susceptible to extinguishing when it is near the component.

The recirculation circuit means that the magnetic fluid is maintained at the correct concentration, i.e. the correct number of magnetic particles are dispersed in a certain volume of a base fluid (e.g. oil or water). The positioning of a portion of the recirculation circuit within the handle of the MPI device, means that the length of supp'y channel between the applicator and the recirculation circuit is reduced. This means very little fluid is stored in the supply channel between operations, and as such there is no need to bleed the channel before use, and the device can be used almost, if not, immediately.

Reference to upper and lower in the present description is used simply to refer to the relative location of features of the described embodiments, and is not intended limit the positioning of the features. It will be appreciated that the device can be held in various positions, such that the position referred to being upper and lower is not at the uppermost or lowermost position.

Although the invention has been described above with reference to one or more preferred embodiments, it will be appreciated that various changes or modifications may be made without departing from the scope of the invention as defined in the appended claims.

For example, the button may be removed from the handle for maintenance purposes.

Generally, a seal on the switch may have a life of approximately 6 months, after which the seal will need replacing. Permitting the button to be removed allows easy access for replacing the seals.

Further, a groove may be provided in the handle of the MPI device extending from the button of the device to a lower part of the handle. After a period of time the seals will generally start to leak. The groove directs the fluid from the point at which it leaks, i.e. around the button area, to an exit point from the handle. When not in use, the MPI device may be mounted above a collection tank to collect any leaking magnetic fluid.

This reduces the waste of any leaking fluid.

A battery may be supplied instead of use of a power lead.

In exemplary embodiments, the device may be configured to be programmable for an inspection routine, including the steps of magnetising a component, applying magnetic particles to a component and inspecting a component, The MPI device may comprise a button or toggle for selecting and/or activating an inspection program. For example.

an operator may be able to scroll through programs to select a desired program, position a slide button on a desired program or press a button to activate a program.

The button or toggle may be positioned on the handle.

Further alternative embodiments are shown in Figures 4 to 8. The MPT device may have a connection to a magnetisation source. A button 74b may be provided for an operator to activate and deactive the magnetisation source. For example, the button may be connected to a switch for current flow through a component to be inspected for direct magnetisation, or through a nearby element for indirect magnetisation of a component. The provision of button 74b is further advantageous because it permits an operator to control the magnetisation of a component, the application of magnetic particles to a component, and the inspection of a component using a single hand.

In the embodiment shown in Figures 4 to 8, the button 74b is positioned on the handle 1 2b of the MPI device I Ob. The button 74b is positioned on the right hand side of the handle and a button 40b for actuating a switch of the supply channel is positioned on the left hand side, but in alternative embodiments the button 74b may be on the left hand side and the button 40b may be on the right hand side of the MPI device lOb.

Such positioning of the buttons permits ease of actuation for an operator.

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Further, providing an actuator on the handle of the device permits an operator to activate the magnetic field, apply magnetic particles to a component for inspection, and inspect a component (i.e. direct the UV light) using a single hand. This means that an operator is able to fully concentrate on a component under inspection because there is no need to look away and become distracted from a component under inspection. It can also mean that an operator does not waste time looking for inking out hoses, or foot switches, and also does not waste time trying to re-focus on a test area. Thus, inspection integrity can be improved and the time taken to inspect a component can be reduced.

The MPI device of Figures 4 to 8 is provided with a mount for a UV light. In this embodiment, the mount has a concave surface positioned at an upper end of the handle 12b. The concave surface 76b is shaped to support a UV light that can be seated on the concave surface and attached to the MPI device.

Yet a further alternative MPI device is shown in figure 9. The MPI device lOc shown in Figure 9 is similar to the device of Figure 4 to 8. but the MPI device I Oc of Figure 9 has an indicator 78c. In this embodiment, the indicator 78c is a light. The indicator 78c is provided to indicate when a magnetisation source connected to the MPI device lOc is activated or deactivated. In this embodiment, the light is lit when the magnetisation source is activated and unlit when the magnetisation source is activated, but any alternative means of indication may be used, for example a green light may indicate that the magnetisation source is activated and a red light may indicate that the magnetisation source is deactivated. The indicator may show that the magnetisation source is activated when a current is flowing either through a component or through an outside sow-ce provided to magnetise the component. Such an indicator reduces the need for an operator to thok away from a component under inspection, which eases the inspection process.

Claims

Claims I. A magnetic particle inspection (MPI) device comprising: a light source for illuminating an object or component under test; a magnetic particle applicator for selectively applying magnetic particles to an object or component under test; a handle for manual positioning of the light source and applicator at a desired location relative to an object or component under test; and a flowpath for directing a flow of magnetic fluid within the device; wherein the flowpath comprises a supply channel for receiving fluid from a remote supply and conveying said fluid to the applicator, and a bypass channel for returning fluid supplied to the device.
2. The MPI device according to claim 1, wherein the bypass channel forms part of a circulation system between the device and a remote source of fluid.
3. The MPI device according to claim I or 2, wherein the supply channd is ocated within the handle of the device.
4. The MPI device according to any one of daims I to 3, wherein the by-pass channel extends at least partly within the handle of the device.
5. The MPI device according to any one of claims 1 to 4. wherein the device is configured for selectively supp'ying a flow of magnetic fluid to the applicator.
6. The MPI device according to claim 5, wherein a supply switch having an open and a dosed position is provided within the supply channel for selectively interrupting a flow of fluid to the applicator.
7. The MPI device according to claim 6 comprising an acutator for selectively actuating the supply switch between the open and closed position.
8. The MPI device according to any one of claims 1 to 7, wherein the device includes a supply conduit extending into the handle, for conveying fluid to the device from a remote source.
9. The MPI device according to claim 8, wherein the conduit is alTanged in communication with the supply channel and the bypass channel, so that fluid from the remote source may flow along the supp'y channel and the bypass channel and, if flow within the supply channel is interrupted, the flow will continue along the bypass channel for return to the remote source.
10. The MPI device according to claim 9, wherein the device includes a conduit extending from the handle and in communication with the bypass channel, for returning fluid to the remote source.
II. The MPI device according to any one of daims I to 10, wherein a valve is provided in the bypass channel, for adjusting the pressure of fluid within the device, and thereby controlling or adjusting the pressure of the magnetic fluid flowing towards the applicator.
12. The MPI device according to any one of claims 1 to 11, wherein the device is configured for one-handed operation for applying the magnetic fluid and for inspecting a surface of a component under test dunng or after application of the magnetic fluid using said light source.
13. The MPI device according to any one of the previous claims compilsing a connection to a magnetisation source.
14. The MPI device according to claim 13, compdsing an actuator positioned on the handle for activating and deactivating the magnetisation source.
15. The MPI device according to claim 13 or 14, comprising an indicator positioned on the handle to indicate when the magnetisation source is activated or deactivated.
16. The MPI device according to any one of claims 13 to 14, wherein the device is configured to be programmable for an inspection routine, including the steps of magnetising a component, applying magnetic particles to a component and inspecting a component.
17. The MPI device according to claim 16 comprising a button or toggle positioned on the handle for sdecting and/or activating an inspection program.
18. The MPI device according to any one of claims ito 17, wherein the light source is an Ultra Violet (UV) light source.
19. The MPI device according to claim 18, wherein the light source is an UV light emitting diode (LED).
20. An MPI apparatus including a reservoir of magnetic fluid, and a device according to any of claims I to 19 wherein the device is arranged in flow communication with the magnetic fluid in the reservoir.
21. The MPI apparatus according to claim 20, wherein the apparatus is configured to allow fluid to return to the reservoir from the device.
22. The MPI apparatus according to claim 21, wherein fluid returning to the reservoir is cooled en route between the device and the reservoir.
23. A bench inspection unit for MPI inspection comprising an inspection bench for holding a component under test, and the MPI apparatus according to any of claims 20 to 22.
24. A method of MPI inspection, the method comprising the steps of: applying a magnetic fluid to a component using a hand held MPI device; using said hand held MPI device to illuminate said component and locate surface defects using an ultra violet light source; wherein the hand held MPI device is connected to a tank for storing said magnetic fluid, and a circulation system is used to selectively circulate said magnetic fluid between the device and the tank.
25. The method according to claim 24 carried out using the MPI device according to any of claims ito 19.
26. The method according to claim 24 calTied out using the bench inspection unit according to claim 23.
27. A magnetic particle inspection (MPI) device comprising: a mount for a light source for illuminating an object or component under test; a magnetic particle applicator for selectively applying magnetic particles to an object or component under test; and a handle for manual positioning of the light source and applicator at a desired location relative to an object or component under test; and a flowpath for directing a flow of magnetic fluid within the device; wherein the flowpath comprises a supply channel for receiving fluid from a remote supply and conveying said fluid to the applicator, and a bypass channel for returning fluid supplied to the device.
28. The MPI device according to claim 27, wherein the mount comprises a concave surface positioned at an end of the handle.
29. A magnetic particle inspection (MPI) device comprising: a mount for a light source and/or a light source for illuminating an object or component under test; a magnetic particle applicator for selectively applying magnetic particles to an object or component under test; a handle for manual positioning of the light source and applicator at a desired location rdative to an object or component under test; a connector for connection to a magnetisation source; a first actuator for actuating a supply of magnetic particles to the magnetic particle applicator; and a second actuator for actuating a magnetisation source for magnetising a component for inspection.
30. The MPI device according to claim 29, comprising an indicator to indicate to a user when a connected magnetisation source is activated or deactivated.
31. The MPI device according to claim 30, wherein in indicator is an indicator light positioned so as to be in a position colTespondmg to a user's line of sight.
32. The MPI device according to any one of claims 29 to 31 comprising an actuator and actuation system for selection of an operating program.