Dakota Ultrasonics DFX-8 plus MANUAL2 - Manual (Page 73)

DFX-8
Ultrasonic Thickness Gauge
69
Rectified (RECT) A-Scan
The RF mode shows the waveform in a similar fashion to an oscilloscope. It shows
both the positive and the negative peaks. The peak (either positive or negative)
selected for measurement is shown in upper portion of the display.
It’s important to note that a measurement must fall inside the displays viewable range
in order to see the waveform. However, even if the waveform is outside of the
viewable range of the display, a measurement can be taken and viewed on the digital
readout. If the wave is outside of the display range, you can manually change the
range by adjusting the Delay and Width values, or you can use the Auto Find
feature located in the UTIL menu of the tabbed menu items. Refer to page 112 for
additional information on the Auto Find feature.
The following is a list of the viewable features on the display:
A. Repeatability/Stability Indicator – This indicator should be commonly used
in conjunction with the digital thickness values displayed. When all the vertical
bars are fully illuminated and the last digit on the digital thickness value is
stable, the DFX-8 is reliably measuring the same value 3 to 200 times per
second, depending on which measurement mode and features are enabled.
B. Battery Icon – Indicates the amount of battery life the DFX-8 has remaining.
C. Detect Indicator – The broken vertical line displays the zero crossing
detection point on the waveform where the measurement has been obtained.
Notice that the digital thickness readout is the same as the location of the
detect indicator according to the measurements labels F, also in the diagram.
D. Baseline - The horizontal trace across the A-scan presentation for a no signal
condition. It represents time and is generally related to material distance or
thickness.
E. Gate – An electronic feature that allows the user to monitor signals inside the
boundaries of the gate settings. The height of the gate from the baseline is