Dakota Digital MMX-6 operation manual Condition and Preparation of Surfaces

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MMX-6 DL Ultrasonic Thickness Gauge

Condition and Preparation of Surfaces

In any ultrasonic measurement scenario, the shape and roughness of the test surface are of paramount importance. Rough, uneven surfaces may limit the penetration of ultrasound through the material, and result in unstable, and therefore unreliable, measurements. The surface being measured should be clean, and free of any small particulate matter, rust, or scale. The presence of such obstructions will prevent the transducer from seating properly against the surface. Often, a wire brush or scraper will be helpful in cleaning surfaces. In more extreme cases, rotary sanders or grinding wheels may be used, though care must be taken to prevent surface gouging, which will inhibit proper transducer coupling.

Extremely rough surfaces, such as the pebble-like finish of some cast iron, will prove most difficult to measure. These kinds of surfaces act on the sound beam like frosted glass on light:, the beam becomes diffused and scattered in all directions.

In addition to posing obstacles to measurement, rough surfaces contribute to excessive wear of the transducer, particularly in situations where the transducer is "scrubbed" along the surface. Transducers should be inspected on a regular basis, for signs of uneven wear of the wearface. If the wearface is worn on one side more than another, the sound beam penetrating the test material may no longer be perpendicular to the material surface. In this case, it will be difficult to exactly locate tiny irregularities in the material being measured, as the focus of the soundbeam no longer lies directly beneath the transducer.

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Contents Dakota Ultrasonics Dakota Ultrasonics Contents Disclaimer Very Important Introduction Blank Keypad OperationDakota Ultrasonics MMX-6 DL Ultrasonic Thickness Gauge Dakota Ultrasonics Display Dakota Ultrasonics Is currently operating in echo-echo Thru-paint/coating mode Transducer Making Measurements Dakota Ultrasonics Condition and Preparation of Surfaces Performing a Probe-Zero Probe ZeroCalibration Dakota Ultrasonics Calibration to a known thickness Dakota Ultrasonics Calibration to a known velocity Dakota Ultrasonics Two Point Calibration Units in/mm MMX-6 DL Modes Changing Units in / MMBack light Using The Back LightScan Mode Alarm Mode Using Scan ModeUsing the Beeper Dual-Multi Mode RS232 Serial Port & The Data Logger Connecting To a ComputerUsing The Data Logger Using the Data Logger Clearing a Storage Location Clearing an Entire File Sending All Files to a Computer Clearing all FilesPrinting a File Transducer Selection MMX-6 DL Ultrasonic Thickness Gauge Dakota Ultrasonics Blank Power Source Product Specifications PhysicalAppendix a KeypadMeasuring hot surfaces Appendix BApplication Notes Measuring pipe and tubing Measuring laminated materials Measuring Through Paint & Coatings Blank Sound Velocities of some Common Materials Appendix CBlank Warranty Statement Warranty Information
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