Volume Fraction

Measurement screen according to ASTM E562

1. Introduction

Volume Fraction measurement is carried out in accordance with ASTM E562 standards, using the Point Count method to determine the volume fraction of specific metallographic phases.

All measurements are expressed in the SI (International System of Units), and terminology follows the conventions defined in ASTM E7.

2. Image Capture

Polished metallographic specimens are placed on the microscope stage, and approximately 30 microstructure images are captured using the prepared camera.

During this process, care must be taken to avoid overlapping fields of view between the captured images.

3. Image Loading

When the captured images are loaded, they appear in the gallery window on the right side of the screen.

By selecting the first image with the mouse, it will be displayed in the Work Space and prepared for measurement.

Before loading images for measurement, if any unrelated images are already open in the gallery, they should be closed using the Close All button.

4. Phase Detection and Measurement

If the phases in the image are clearly distinguishable, select “Grey Scale” in the Color Space option, define the desired Range, and check the Test box. The selected phase will then be highlighted with the specified color overlay.

For fine detection, adjust the start and end values of the Range until the target phase is properly identified. Once detection is complete, press the MEASURE button. A square Point Grid will be automatically placed on the screen, and the software analyzes the phase located at each grid intersection, recording the score automatically for every point.

• If a phase overlaps a grid position and lies on a boundary or in an ambiguous location, it is counted as 0.5.

• The phase detection process can be repeated while observing the detection results.

  When the results are satisfactory, press the Next button to load the following image and perform the same procedure.

• In this context, each image is referred to as a Field, and its number is displayed as Field # in the measurement dialog.

  The measurement results for each field are shown at the top of the Volume Fraction dialog window.

5. Aggregation and Display of Results

As each loaded field is measured, the results are automatically aggregated, and the mean, standard deviation (STDEV), 95% confidence interval (CI), and %RA are updated.

However, STDEV, 95% CI, and %RA values are only calculated starting from the fifth field.

After reaching the final field (image) and completing the measurements, press the Export to Excel button to generate the test report.