H&A viewers available on the market show several disadvantages.
Using them in a lab environment makes objective grading very difficult.
There are several limitations: the diamond has to be centered manually, the alignment of the table perpendicular to the
viewing axis is tedious and inaccurate, head movements make different viewing angles possible and, last but not least,
the fixed magnification makes viewing of smaller stones very difficult.
The custom made H&A by HRD Antwerp viewer, developed for HRD Antwerp by
WTOCD, solves all these problems. The tool can be used for visualizing both hearts and arrows patterns in one setup without turning the diamond.
There is a centering device build in to ensure that the diamond
is perfectly aligned with the viewing axis. De holder has a
coated glass plate to enable the bidirectional viewing.
To reach
the maximum
precision for the range of 0.4 to 3.5ct the device
has two high resolution camera's inside. The images are
digitally scaled to have an uniform view of small and bigger
diamonds. The images are captured by the connected computer through a USB link. A proprietary software was
developed by WTOCD to analyze the images according to the H&A by
HRD Antwerp guidelines. Based on measurements of the H&A patterns, an expert system makes an evaluation of the guidelines.
The system delivers consistent,
objectively measured, H&A grades.