Dakota Digital MX-5 operation manual Condition and Preparation of Surfaces

Page 16

Dakota Ultrasonics

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.

12

Page 15 Page 17
Image 16
Page 15 Page 17
Contents P-114-0002 Page Contents DisclaimerBlank Introduction Blank Operation KeypadDakota Ultrasonics MX-5 Ultrasonic Thickness Gauge Dakota Ultrasonics Display Dakota Ultrasonics Transducer Making Measurements MX-5 Ultrasonic Thickness Gauge Condition and Preparation of Surfaces Probe Zero Performing a Probe-ZeroCalibration Calibration to a known thickness Calibration to a known velocity Two Point Calibration Scan Mode Moving series of dashes instead of a thickness value. WhenAlarm Mode Using the BeeperDifferential Mode RS232 Serial Port Connecting To a Computer Transducer Selection Dakota Ultrasonics MX-5 Ultrasonic Thickness Gauge Blank Product Specifications Physical Appendix aBlank Appendix B Application Notes ∙ Measuring pipe and tubing∙ Measuring laminated materials MX-5 Ultrasonic Thickness Gauge Blank Appendix C Sound Velocities of some Common MaterialsBlank Warranty Information ∙ Warranty Statement ∙SONOTECH, INC
Top Page Image Contents