Home Theater System Household Appliance Integrated Telephone System Microwave Oven Personal Care Portable Radio Portable Stereo System Print Board Projection Television Projector Recording Equipment Remote Control Rice Cooker Security Camera Solar Panels 3. Speakerphone TV Receiver TV Video Accessories Telephone Telephone Accessories Television For example, Anti-Semitic content, racist content, or material that could result in a violent physical act.
For example, a credit card number, a personal identification number, or an unlisted home address. Note that email addresses and full names are not considered private information. Would you like to receive an email when new answers and questions are posted? Please enter your email address. Home Automotive Car Radio Panasonic cq dfx Panasonic cq dfx Features of the DFX The DFX is a user-friendly ultrasonic digital flaw detector and thickness gauge, which is simple to use and provides the experienced ultrasonic operator with a full-function device that incorporates many productivity enhancing features.
All of the features of the DFX are accessed through a menu system under the control of tactile touch keypads. Fundamentals of Ultrasonic Testing The DFX is a single-channel ultrasonic inspection instrument used for the inspection of homogeneous materials for the presence of inclusions, porosity and other discontinuities that could affect the performance of materials and components. It can also be used for thickness gauging of homogeneous materials, requiring access from only one side of the test piece.
The reflection of sound energy is a function of the ratio between the acoustic impedance of the discontinuity and the base material. The acoustic impedance of a given material is the product of the density and the velocity of sound in the material. The higher the ratio, the more sound energy that will be reflected. The principle of ultrasonic testing is shown in Figure 1 which shows the ultrasonic energy in the test piece and the resulting instrument display.
Thickness gauging with the DFX operates on the principle of time-of-flight of measurement. This principle utilizes the precise timing of the transit time of a short burst of high frequency sound energy through a material under test.
This technique, derived from sonar and radar, has been widely applied to nondestructive inspection and dimensional measurement processes. As the sound beam enters the material, it spreads and becomes weaker.
Therefore, discontinuities farther from the transducer or front surface of the test part produce a lower response from the system.
In addition, discontinuities which present their predominant planar surface to the axis of the sound beam will produce larger reflections than those which only present an edge to the sound beam.
Some knowledge of these factors along with an understanding of how discontinuities are formed in the test part are important for the proper use and effectiveness of this instrument. The frequency of the generated sound waves is far beyond the range of human hearing and can be in the range of 0.
Sound energy at these high frequencies does not travel well through air. On the other hand, higher frequency sound energy attenuates more and tends to scatter in large grain material, causing a loss of sensitivity in thicker sections of material. Proper ultrasonic testing requires careful selection of the frequency to obtain a desired balance between sensitivity and penetration.
Responses from small discontinuities in the near field can be irregular. Beam spread is an important consideration when inspecting discontinuities that may be close to geometric features of the test piece such as corners and fillets.
Such geometric features can cause erroneous indications at distances where the beam spread is a factor. A longitudinal wave is one in which the particle motion is in the same direction as the propagation of the wave.
Straight beam testing is used for most flaw detection and thickness gauging. This design improves near surface resolution by separating the initial pulse from the received echoes and by providing a slight focus of the sound beam.
Any excess buildup of couplant could cause readings that are thicker than actual. This is because the couplant can add to the measured value. Issue 3 Figure 5 — Thickness Gauging on Pipe The same precautions are true for pitted front surfaces as shown in Figure 6.
A shear wave is one in which the particle motion is perpendicular to the direction of propagation. Shear waves have lower velocities and correspondingly larger wavelengths than the longitudinal wave.
Angle beam or shear wave testing is most often used for the inspection of welds. Another reason to use angle beam testing on welds is to position the sound beam more normal to the expected discontinuities since the flaws in welds are usually perpendicular to the test surface with the exception of porosity.
Figure 8 shows the principles of angle beam weld testing. Depending on the incident angle, refracted sound beams can also produce components of longitudinal energy, surface wave energy and Lamb wave energy.
Although these advanced topics are beyond the scope of this manual, it is important to know that multiple modes can occur simultaneously which may lead to spurious indications. Surface wave inspection can be used to detect cracks on the surface of materials. NOTE: Angle beam testing is a more advanced ultrasonic testing method. Immersion testing offers the advantages of more uniform coupling, increased testing speeds and the ability to focus the sound beam.
All of these factors can lead to improved sensitivity and reliability. This has the effect of concentrating the Figure 9 — Immersion Testing Method sound energy for improved sensitivity and resolution.
When the sound beam strikes a test piece, however, the energy is usually focused more sharply, resulting in a reduction of the focal length. This re-focusing effect is shown in Figure Concave surfaces tend to increase the focal distance and spread the sound beam. Quick Start 5. These buttons are described below along with the mnemonics used throughout this manual. Operates as a toggle. PWR N. B Random lines or characters may be displayed for a second or two after switch on, before the memory is initialized, this is normal.
The selected value is indicated at the top right-hand corner of the Gain Box, which is always located at the bottom right side of the screen. This is a momentary button with no repeat. This is always located at the bottom right side of the screen.
This is a repeat button with acceleration to facilitate quick scrolling of the value. The mode selected is displayed in a highlighted box below the Gain box at the lower right of the display. This is a momentary button with no repeat These buttons move the highlighted cursor along the top of the screen left and tight to the sub menu to be selected. These are momentary buttons with no repeat. The parameter boxes on the right of the screen change as the sub menu is selected.
In the print mode, OK acts as the print button. This button operates in connection with the plain yellow buttons next to the parameter boxes to increase the value or step the selection in the positive direction.
This button operates in connection with the plain yellow buttons next to the parameter boxes to decrease the value or step the selection in the reverse direction. This button selects between the two main menus at the top of the screen. The menus are described in Section 6. This is a useful feature for holding an echo for evaluation. Pressing the button a second time selects Peak mode, which holds and updates all echoes on the display during inspection.
This feature allows an envelope or echo dynamic pattern to be drawn on the screen which is useful for angle beam inspection to locate the peak signal. When in this mode, a box is highlighted showing PEAK below the graticule. This is a momentary button with no repeat action. This button selects the help menu which overlays the display.
Description of the active menu. Calibration procedure. Pressing the HELP button again at any point in the help screens returns the display to normal mode. When a menu box is selected, it will be highlighted. Some menu boxes contain a single or double arrow point indicating slow or fast adjustment mode. Press the button next to the selected box a second time to toggle between slow and fast modes.
Rx BNC or Lemo 1 connector is the transmitter and receiver socket used for single transducers or as the transmitter only, for twin or dual transducer operation. A two-pin socket used to connect the battery charger for recharging the battery pack.
A red dot is provided on both the socket and plug to facilitate alignment. Refer to Section 7 for information on power supplies and charging of the battery pack.
That is, whatever the calibration settings are just prior to turning the instrument off will be the settings in place the next time the instrument is again turned on. This is especially true when beginning a new test procedure or going from flaw detection to a thickness gauging procedure.
A reset function is provided to facilitate the returning of all panel calibration settings to the factory defaults. To reset panel settings to factory defaults: 1. Switch the instrument off. Depress the yellow MEM button and hold while switching the instrument on until the reset display is seen. NOTE: Before performing this procedure, be sure to save any favorite panel calibration settings to memory by using the procedure outlined in Section 6. Factory default values: Zero: 0.
Erasing all of these values accidentally could have far reaching consequences. Should the occasion arise for a need to erase all of the memory, call the factory for instructions. Units shown are in mm. When making a quick adjustment on a menu parameter, press the adjacent yellow button until the double arrow appears next to the parameter name.
Using an appropriate calibration block, adjust the GAIN parameter to establish the correct sensitivity. Adjust other parameters as necessary to optimize the calibration. For more in-depth features of the DFX, see Section 6. Units shown are in metric. Select a suitable transducer, preferably a 5MHz, half inch diameter broadband type.
Select an appropriate calibration block with at least three known thickness sections covering the range to be inspected and made from the same material as that of the test piece. Calibrate the thickness readout on the selected calibration block using the procedure in Section 6. You are now prepared to perform basic thickness gauging. Adjust parameters as necessary to optimize the calibration. Detailed Operation Instruction Before proceeding with this section, the user should be familiar with the front panel controls described in Section 5.
It is also assumed that the user has a good understanding of the theory and practice of ultrasonic testing. Units are microseconds in both mm and inch modes. Used to calibrate the screen and thickness span readout based on the velocity of sound in the test material. Units are meters per second in mm mode and inches per microsecond in inch mode. The range is 5mm to 10 meters. Ranges are 1, 2, 5, 10 narrow bands and WIDE band 1. FREQ 5. PRF MAX Used to set the maximum pulse repetition frequency that may be reduced for large values of display range and delay.
Selectable values are 35, 63, , , , and 1,Hz. Lower values will reduce ghosting and noise echoes. Usually used to monitor for loss of back wall echo. Only applies to gate 1. OFF: Switches the gate off. Used to set the start position of the gate relative to the initial pulse. Units are mm or inches and range is from 0 to the full time base of the horizontal display. Units are mm or inches and range is from 0. Adjustable in 0. DEPTH MODE: In this mode, gate 1 functions as a depth or thickness monitor and displays the depth D: and height H: of the first signal after the start of the gate that reaches or exceeds the gate level threshold.
Values are displayed in a highlighted box below the A-Trace. The INC button sequences the selection from distance to amplitude to off. BLANK This function sets the blanking distance, as a percentage of the total gate width, which is a blind zone after the first echo, after which a second echo can be measured.
This helps to eliminate undesired noise in the first echo from being measured, as thickness but will limit the minimum thickness capability if set too large.
THICK Set to the thickness of the material being tested to account for multiple skips of the angled sound beam in the test material. ANGLE When highlighted, this cursor allows return to the first main menu by pressing the CURL control.
Please note that this requires a printer with a serial port. This can take considerable time if all AScans are stored. Press it again to return to the Main menu. When moving in and out of the Function menu, the position of the cursors in the Main menu remains in their previous positions.
Gate 1 is used to select the reference echoes. The calibration procedure is described fully in Section 6. The actual distance to the second or thickest reference echo in the calibration block.
Shows the last point created after pressing the OK button. Once drawn, the TCG curve acts as swept gain control on the amplifier to set different gain levels relative to distance. Can be activated in RF or rectified display modes. Cannot be drawn in RF display mode.
It provides a convenient method to automatically calculate the Indication Rating as defined in the code. IL dB The dB required setting the indication to the reference level. AF dB The attenuation factor to correct for the depth of the indication. IR dB The indication rating calculated in accordance with the code. Also the difference the IL and the reference level with correction for attenuation. REF The level selected will affect the battery duration.
A value of 1 gives about 10 hours, whereas a value of 20 will give about 5 hours of operation, assuming the battery is in good condition and at room temperature. NTSC mode will be slightly brighter. Two outputs are provided one for depth and one for amplitude. The outputs are active when the associated gate is triggered. Switching on the outputs will reduce battery duration. Set to OFF when not being used. When selected, the signal resolution and measurement accuracy is reduced.
When moving in and out of the Memory menu, the positions of the cursors in the Main menu remain in their previous positions. The use of this feature is described fully in Section 6. Press OK to recall. Press OK to delete. Press OK again after the confirmation prompt.
Pressing OK will recall the calibration set at which time the Notes can be edited. Press OK to store. VALID indicates that the store location is used. EMPTY indicates that it is not used. These are the steps to follow if the keyboard is connected. The connector is a 5pin one. Store the calibration set to save the notes. Press to scroll through and select a line for editing.
Used to recall a stored A-Scan and settings to the active memory. Shows the notes associated with the stored A-Scan and its settings.
Pressing OK will recall the waveform. Numeric and Sequential modes are available as selected in the T-FN menu. This feature is described fully in Section 6. LOC Used to select the location number for storage or viewing of a thickness reading.
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