Hand-held metal analyzers are changing
the operations of many scrap metal recyclers. With a growing
number of choices in the market, choosing the right metal
analyzer for your needs is the key to obtaining best results.
For most recyclers, that means knowing and understanding
customers' needs first.
Hand-held analyzers identify different materials in a sample
the same way larger instruments do - by analyzing light
energy unique to each element. When groups of elements are
identified in a sample, the analyzer compares the sample
data to possible matches in a library of possibilities.
The library is a database stored in the unit. Each possibility
corresponds to a known material-type.
For recyclers, the portability of hand-helds has simplified
the sorting and identification of metals considerably. Stuart
Freilich, of Universal Metal Corporation, Worcester, Massachusetts
said, "It means we no longer saw off samples and send
them to the lab. Now all of our testing is done right there
on the spot."
There are essentially two types of hand-held metal analyzers
used in scrap metal recycling today - optical emission (OE)
and x-ray fluorescence (XRF). Each type has its advantages
Optical-emission analyzers (OE) are commonly known as "arc/spark"
devices. Essentially, OE analyzers send a charge of electrical
energy to the sample that burns off a small portion of the
material. This charge "excites" the atoms on the
surface of the metal and causes moving electrons to emit
light. The light is reflected back to the unit and analyzed
to determine the presence of specific elements in the sample.
OE analyzers have typically been used to identify a wide
range of metals, and they are essential for identifying
The second type of metal analyzer uses x-ray fluorescence,
or (XRF) technology. Like OE-type analyzers, XRF analyzers
work by "exciting" the atoms in a metal sample
and analyzing light emitted by electrons in motion. With
an XRF-type analyzer, metal samples are showered with x-rays
from the instrument. The x-rays are returned to the unit
to identify the material in the sample.
"Recyclers should consider the materials they primarily
deal with," Tom Anderson, director of marketing for
Niton, LLC, pointed out. "XRF is not well suited to
analysis of aluminum alloys or mild steel, whereas these
are the primary strengths of OE systems. OE systems are
really the only good solution for someone dealing in these
types of metals," he added.
Randy Moffat, vice president, sales &
marketing of Angstrom, Inc., commented, "X-ray analyzers
are good for most materials but won't analyze aluminum materials
to the degree that most users require. Most arc/spark type
analyzers can analyze the full range of metals, as long
as C, P and S are not required." XRF analyzers are
well suited to high temperature metals, nickel alloys, stainless
steels and titanium.
There are differences in ease of operation as well. XRF
systems are generally simpler to use, while some OE analyzers
may require higher levels of knowledge, experience and technical
ability of the operator.
Among XRF-type analyzers, there is still another consideration.
The method of excitation - either by radioisotope, or through
a newer, miniature x-ray tube technology. Each has implications
for registration and licensing requirements.
Owner/operators of radioisotope-based XRF analyzers possess
and use their devices under the provisions of either a specific
or general Radioactive Materials License (RML). Tony Honnellio,
Corporate Radiation Safety Officer for Niton, LLC pointed
out, "Prior to taking possession of a radioisotope-based
XRF analyzer, owner/operators should first determine whether
or not they plan on using the instrument(s) in multiple
states. If so, the owner should apply for a specific license
with the Nuclear Regulatory Commission (NRC) or an agreement
state. The specific RML would then be used to seek approval
(reciprocity) to use an XRF analyzer in another state or
NRC jurisdiction. Agreement states are those states that
have signed an agreement with the NRC to regulate possession
and use of byproduct radioactive material within their borders,"
he said. Regulation of byproduct material in non-agreement
states is the responsibility of the NRC.
A list of agreement and non-agreement states can be found
The NRC and some agreement states accept the provisions
of a general license. A general license is issued to owners/operators
through regulation (i.e. 10 CFR 31.5). It indicates that
a device's design has a high level of safety associated
with it. Possessing an XRF analyzer under a general license
reduces the regulatory burden in that one does not have
to apply for and maintain a specific RML. There are limitations
however, especially if one plans on transporting the device
from state to state (see above).
According to Mr. Honnellio, "Owners/operators of generally
licensed devices are still required to conduct leak testing
every six months, provide notification of loss, theft, or
damage and assure that the radioactive material contained
in the instrument is properly disposed of." Additionally,
agreement states may require registration or have other
specific requirements for generally licensed devices. "All
generally licensed XRF analyzers containing more than one
mCi of Americium-241 also require registration with the
NRC or an agreement state," Honnellio added. More information
on general licensing is provided in NUREG 1556, Volume 16,
found at: www.nrc.gov/reading-rm/doc-collections/nuregs/staff/sr1556/v16/index.html.
In turn, owner/operators of x-ray tube-based XRF analyzers
are subject to minimum regulatory requirements as well.
One of the main advantages of x-ray tube devices is the
elimination of certain transportation requirements. However,
these units must be registered with the state when purchased.
Some states may charge a registration fee, require an expert
to evaluate the device, or require operators to have specific
training prior to use of the analyzer. Portable x-ray tube-based
XRF analyzers that are used in more than one state are subject
to the requirements of each state.
What are steel recyclers looking for in an analyzer today?
For most, three priorities were often named.
First, a reasonably priced unit is important. John Hunsaker
of SOS Metals, Gardena, California notes, "Prices on
hand-held units have come down dramatically in the past
three years, but these things still aren't cheap."
Scrap metal recyclers can expect to pay roughly between
$20,000 and $35,000 for a hand-held OE or XRF analyzer.
Larger analyzers - such as those for laboratory use - can
cost as much as $50,000 or more, depending on options or
Next, scrap metal recyclers cited ease of use. While specialized
operator training is available, most recyclers prefer analyzers
be as simple to use as possible. "People have a lot
to do these days," said Mr. Freilich. "Most recycling
operations just don't have experienced metallurgists on
staff," he added.
The third priority was reliability, or "reproducibility"
in the case of hand-held analyzers. If recyclers depend
on an instrument to guarantee material certifications, an
inaccurate analysis could prove costly.
When choosing a hand-held analyzer, scrap metal recyclers
should consider the training, support and post-sale service
offered by each manufacturer. Mark Lessard, business development
manager, Oxford Instruments, Inc., Concord, Massachusetts,
pointed out, "Service policies should include a guaranteed
turnaround on repairs in a reasonable period of time. Loaner
units while repairs are being made should also be available."
In addition, a good supply of replacement parts will help
reduce any downtime in the event repairs may be needed.