ARL 3460 Metals Analyzer
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Technical Description
2
3.
SAMPLE PREPARATION
For accurate and reproducible measurements it is essential to have a homogeneous sample,
without inclusions and with a clean, flat surface. Thus a suitable sample taking method together
with careful sample surface preparation are absolutely essential for good analysis.
For sample taking and surface preparation, several kinds of moulds and preparation machines are
readily available for purchase.
If required, your local ARL representative will advise you regarding which type and model best
suites your application. Following are some general examples of the various sample mould types
with associated sample preparation machines and their main applications.
3.1
Sample Taking – Moulds
Sample taking for spectrometer analysis is a fundamental technique. Several spectroscopy books
explain the procedure and advise which moulds should be used for a given application. DIN and
ASTM standards also provide specifications and information about this subject.
Generally:
·
The sample cooling must be rapid to produce a fine grain metallic structure.
·
The mould is normally made of copper and kept very clean.
·
Any mould not in use must be turned upside down (or covered) to avoid dirt or any other
material ingress.
Here are some examples of moulds that are suitable for casting good quality samples and adapted
for optical emission spectroscopy analysis. A probe for direct sample taking is also shown.
Non-Ferrous Metals
The mushroom form sample taking mould is the most widely used for non-ferrous metals. There
are however segregation risks, and the mould diameter must be adapted accordingly.
cut
here
useful surface
for analysis
