Title of Invention	AN ULTRASONIC PROBE ASSEMBLY FOR ULTRASONIC TESTING
Abstract	The present invention relates to an ultrasonic testing comprising a pair of transducers (3,4), one a transmitter (3) and the other a receiver (4) said transducers (3,4) arranged on a perspex sheet (2) at a fixed distance from one another for measurement of time of flight (TOF) of ultrasonic waves from the surface of a test piece (7).

Full Text

FIELD OF APPLICATION The present invention relates to an ultrasonic probe assembly for ultrasonic testing using ultrasonic surface wave (Rayleigh / Lamb waves). BACK GROUND OF THE INVENTION Ultrasonic probes are used in the field of non-destructive evaluation and characterization of materials. The probes can be used for the evaluation of mechanical properties and micro-structure of semi-finished, finished flat / forged / cast steel products. The probes can also be used for the evaluation of surface as well as internal flaws in semi-finished, finished flats / forged / cast steel products as well as industrial components such as rolling mill rolls, shafts, pipes / tubes etc. In known ultrasonic probes where same transducer works as a transmitter as well as a receiver, some of the information about the condition of the test object may be missing because of the presence of dead zone. When two separate ultrasonic probes are used to produce and receive ultrasonic surface waves (Rayleigh / Lamb waves) for measurement of time of flight (TOF) of ultrasonic waves between them, the distance between the probes has to be measured with the help of some measuring device each time for a set of measurements. In this process, there is a chance for error in measurement of time of flight (TOF) because even a very slight variation in the measurement of distance between the probes can cause a huge error in time of flight (TOF) measurement. This manual process for keeping the probes apart at a fixed and accurate distance needed a lot of time and concentration. Also holding the probes with both the hands was an unergonomical practice. In order to avoid and prevent the errors in measurement of time of flight (TOF) as well as saving the time in taking accurate and precise measurement of time of flight (TOF), there was a need for a device / assembly which can be used effectively and ergonomically. SUMMARY OF THE INVENTION The main object of the present invention therefore, is to provide an ultrasonic probe assembly using two separate transducers as transmitter and receiver provided at a fixed distance for not only eliminating the dead zone, but also for more accurately measuring the time of flight of ultrasonic waves from transmitter to receiver. This time of flight (TOF) measured can be utilized for materials characterization. The probe assembly of the present invention can further be used for the evaluation of surface, as well as internal flaws. Thus the present invention provides an ultrasonic probe assembly for ultrasonic testing, comprising: a pair of transducers, one a transmitter and the other a receiver, said transducers arranged on a perspex sheet at a fixed distance from one another for measurement of time of flight (TOF) of ultrasonic waves from the surface of a test piece. BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS The invention can now be described in detail with the help of the figures of the accompanying drawings in which: Figure 1 shows in a pictorial view the ultrasonic probe assembly of the present invention. Figure 2 schematically shows the plan, front and side views of the ultrasonic probe assembly of Figure 1. DETAILED DESCRIPTION Figure 1 is a photographic view showing the ultrasonic probe assembly of the present invention in use for measurement of time of flight (TOF) of ultrasonic surface waves (Rayleigh / Lamb waves). Figure 2 shows the ultrasonic probe assembly 1 in plan, elevation and side views. The assembly comprises a perspex sheet 2 having two rectangular holes for receiving two transducers, one transmitter 3 and one receiver 4. The perspex sheet 2 is chosen because it is transparent and light in weight. The perspex sheet 2 can be of size 200 x 30 x 10 mm and the two holes of size 30 x 16 mm each can be arranged at a fixed distance D of say 100 mm. These holes can be placed 20 mm away from the two edges of the perspex sheet 2. The two rectangular holes in the perspex sheet 2 for receiving two transducers 3, 4 are made slightly over size of the transducer size. The transducers 3, 4 used as ultrasonic surface wave probes can be of 4 M Hz frequency with crystal size of 8 x 9 mm. The transducers 3, 4 are fitted with lemo connectors 5, 6 and fixed to the perspex sheet 2 rigidly with adhesive. The sized of the ultrasonic probe 3,4 can be 30 x 16 x 22 mm. While fixing the ultrasonic probes 3, 4 on to the perspex sheet 2, care is to be taken to see that the position of the plane of the perspex sheet 2 is parallel to the contact surface of the test piece 7 and that distance d between the transducers 3, 4 and the test piece 7 is about 2 mm. Care should also be taken for convenient insertion of the lemo connecting cable to the ultrasonic probes. Thus the present invention is different from the known probes in which the same transducer works as a transmitter as well as receiver and due to presence of dead zone some information about the test object condition are missing. Use of two separate transducers (transmitter and receiver fixed at a fixed distance) in the present invention not only eliminates the dead zone but allows the measurement of time of flight of ultrasonic waves from transmitter to receiver more accurately which can be utilized for materials characterization. Further the probe can be used for evaluation of surface as well as internal flaws. WE CLAIM 1. An ultrasonic probe assembly for ultrasonic testing, comprising: a pair of transducers, one a transmitter and the other a receiver, said transducers, arranged on a perspex sheet at a fixed distance from one another for measurement of time of flight (TOF) of ultrasonic waves from the surface of a test piece. 2. The ultrasonic probe assembly as claimed in claim 1, wherein said transducers are arranged at a distance of 100 mm from one another. 3. The ultrasonic probe assembly as claimed in claim 1, wherein said transducers used as ultrasonic surface wave probes are of 4 MHz frequency having a crystal size of 8X9 mm. The present invention relates to an ultrasonic testing comprising a pair of transducers (3,4), one a transmitter (3) and the other a receiver (4) said transducers (3,4) arranged on a perspex sheet (2) at a fixed distance from one another for measurement of time of flight (TOF) of ultrasonic waves from the surface of a test piece (7).

Documents:

964-kol-2005-abstract.pdf

964-kol-2005-claims.pdf

964-kol-2005-correspondence.pdf

964-kol-2005-description (complete).pdf

964-kol-2005-drawings.pdf

964-kol-2005-examination report.pdf

964-kol-2005-form 1.pdf

964-kol-2005-form 18.pdf

964-kol-2005-form 2.pdf

964-kol-2005-form 3.pdf

964-kol-2005-form 5.pdf

964-kol-2005-gpa.pdf

964-kol-2005-reply to examination report.pdf

964-kol-2005-specification.pdf