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A method and a system for testing the bonding of foam insulation (22) attached to metal. The system involves the use of an impacter (10) which has a calibrated load cell (12) mounted on a plunger (14) and a hammer head (16) mounted on the end of the plunger (14). When the impacter (10) strikes the i

A method and a system for testing the bonding of foam insulation (22) attached to metal. The system involves the use of an impacter (10) which has a calibrated load cell (12) mounted on a plunger (14) and a hammer head (16) mounted on the end of the plunger (14). When the impacter (10) strikes the insulation (22) at a point to be tested, the load cell (12) measures the force of the impact and the precise time interval during which the hammer head (16) is in contact with the insulation (22). This information is transmitted as an electrical signal (20) to a load cell amplifier (28) where the signal (20) is conditioned and then transmitted to a Fast Fourier Transform (FFT) analyzer (34). The FFT analyzer (34) produces energy spectral density curves (power plotted against frequency in Hertz) which are displayed on a video screen (39). An operator, by observing the frequency point at which the curve terminates, may determine the quality of the bond. Specifically, the termination frequency of the energy spectral density curve may be compared with a predetermined empirical scale to determine whether a high quality bond, good bond, or debond is present at the point of impact. For future reference and use, data from the FFT analyzer (34) are recorded on a magnetic disk (41) and/or a hard copy is produced by a printer (43).

대표청구항 ▼

A system for testing the bonding of insulation attached to metal comprising: a hammer for impacting insulation attached to metal, said hammer comprising means for measuring the force with which said hammer strikes said insulation and the time duration of the impact and generating an electrical signa

A system for testing the bonding of insulation attached to metal comprising: a hammer for impacting insulation attached to metal, said hammer comprising means for measuring the force with which said hammer strikes said insulation and the time duration of the impact and generating an electrical signal representing said force and said time duration; conditioning means for transforming said electrical signal by amplifying the voltage, said conditioning means having a high input impedance and a low output impedance; and means connected to said conditioning means for using said conditioned signal for determining spectral data representing the amplitude and forced period of vibration of mechanical waves set up when said hammer strikes said insulation and transforming said data into data representing an energy spectral density curve for said mechanical waves, said determining means comprising means for showing a visual presentation of an energy spectral density curve; whereby, a comparison may be made between said energy spectral density durve and a predetermined empirical scale and a determination made as to whether: insulation at the point of impact is well bonded, bonded, or debonded.