Versions Compared

Key

  • This line was added.
  • This line was removed.
  • Formatting was changed.

Introduction


The P-wave velocity gantry measures the speed at which ultrasonic sound waves pass through materials that are placed between its transducers; this includes section halves, discrete samples, and mini-cores.
The three orthogonal sets of piezoelectric transducers allow the velocity to be determined in the X-, Y-, and Z-directions on working-half split-core sections. The P-wave bayonets (PWBs) measure the velocity along the core (Z-direction) and across the split-core face (Y-direction), and a P-wave caliper (PWC) measures the velocity perpendicular to the split-core face (X-direction) (Figure 1). 
For discrete sample cubes, the velocity is measured along each of the three axes separately using the PWC. Mini-cores are measured along the axis of the cylinder (X-direction)For discrete samples cubes and mini-cores, all sample information, including offset, is entered by the user???.


Figure 1. Core section-half liner showing top of section and relative orientations.

...

Figure 5.- Data display on Velocity-Auto box.


It Program also displays a signal graph with a red vertical auto-pick location line (Figure 6), where the program's algorithm has placed the first arrival wave.
Note: Typical slide bar settings are 100 for the stack bar and10mV for the threshold bar.

...

6. Place the cursor in the SCAN field and scan the section label. SAMPLE ID and LIMS ID automatically fills. This ID tag contains sample information on expedition, site, hole, core, section number and length.

...

The signal graph has several different displaysdisplay options, all accessible by clicking on different tabs at the top. To zoom on a graph, pause the program and click on the magnifying glass in the "Graph Tools" box, Figure 7.

...

  1. Pause the program.
  2. Select MANUAL PICK tab (Figure 9).
  3. Click on the crosshair tool on the far left side of the toolbox bar. Hover over the dotted yellow-green vertical pick pink line. When the icon changes, click and drag the pick line to the desired location and release. The Velocity –Manual box will be updated with the manually picked velocity. Both the 'auto-pick' and 'manual pick velocities' are saved simultaneously to the database upload.

...


C) Running a Standard as a QAQC Check

You can run a standards standard to verify if the instrument is giving the expected velocities for the materialmeasuring correctly. There are three materials available as a standard: Aluminum and acrylic are used on the caliper, and a core liner with D.I. water on the bayonets.

...

This document originated from Word document Gantry Velocity: Quick Start Guide Version 1.0; Version 372 written by A. de Loach (2017-12-16). Credits for subsequent changes to this document are given in the page history.

...