Dakota Digital MMX-6 operation manual Measuring Through Paint & Coatings

Page 45

MMX-6 DL Ultrasonic Thickness Gauge

An additional important consideration when measuring laminates, is that any included air gaps or pockets will cause an early reflection of the ultrasound beam. This effect will be noticed as a sudden decrease in thickness in an otherwise regular surface. While this may impede accurate measurement of total material thickness, it does provide the user with positive indication of air gaps in the laminate.

•Measuring Through Paint & Coatings

Measuring through paints and coatings are also unique, in that the velocity of the paint / coating will be significantly different from the actual material being measured. A perfect example of this would be a mild steel pipe with approximately .025” of coating on the surface. Where the velocity of the pipe is .2330 in/µsec, and the velocity of the paint is .0900 in/µsec. If the user is calibrated for mild steel pipe and measures through both materials, the actual coating thickness will appear to be 2.5 times thicker than it actually is, as a result of the differences in velocity. This error can be eliminated by using a special echo-echo mode to perform measurements for applications such as these. In echo-echo mode, the paint / coating thickness will be eliminated entirely and the steel will be the only material measured.

41

Page 44 Page 46
Image 45
Page 44 Page 46
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 / MMUsing The Back Light Scan ModeBack light 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 KeypadAppendix B Application Notes Measuring pipe and tubingMeasuring hot surfaces Measuring laminated materials Measuring Through Paint & Coatings Blank Sound Velocities of some Common Materials Appendix CBlank Warranty Statement Warranty Information
Top Page Image Contents