Measuring Boiler Tube And Oxide Layer Thicknesses; Figure 7-4 Measurement Screen With The Oxide Layer Software Option - Olympus 38DL PLUS User Manual

9. Press [CAL VEL] again.
10. Couple the transducer to the sample with known internal oxide thickness.
11. When the reading is stable, press [ENTER].
12. Using the arrow keys, edit the thickness value to match the known internal oxide
thickness.
13. Press [MEAS] to complete the calibration.
7.3.4

Measuring Boiler Tube and Oxide Layer Thicknesses

With the oxide layer software option, the 38DL PLUS simultaneously measures the
thickness of the boiler tube metal and the thickness of oxide scale that has built up
inside the tube.
Figure 7-4 on page 97 shows the correct ultrasonic signals using the single element
transducer default setup DEF-OXIDE/M2017. The 38DL PLUS makes a standard
mode 2 measurement from the delay line echo (surface of the boiler tube) to the echo
from the inside of the oxide layer (total back-wall echo). The instrument centers the
data window on the detected total back-wall echo and then searches for the
steel/oxide interface echo in the data window. An oxide echo marker indicates the
detected steel/oxide interface echo.
Interface echo
Data window
Oxide layer thickness
Figure 7‑4 Measurement screen with the oxide layer software option
DMTA-10004-01EN, Rev. D, November 2016
Echo from inside of
oxide
Steel/Oxide echo
marker
Tube thickness
Software Options 97