CLA-2 CO:R:C:G 083952 CMS
Mr. Paul Linet, Esq.
Shafner & Gilleran
75 Federal Street, 18th Floor
Boston, MA 02110
RE: Strain Gauges
Dear Mr. Linet,
This responds to your request on behalf of BLH Electronics,
Inc. dated November 4, 1988, supplemented January 30, 1989 for a
binding classification ruling for certain strain gauges. Our
ruling follows.
FACTS:
The merchandise consists of thin metallic foil electrical
circuits bonded to flexible organic backings. The articles are
commonly referred to as "strain gauges". Strain gauges are
sensor devices used to test or measure physical force or stress.
The devices output an electrically measurable signal in response
to a mechanical stress input. The mechanical stress input is
measured by the increase in resistance which occurs when the foil
circuit is stretched or otherwise subjected to force or stress.
Strain gauges have many applications. The devices can be
attached to a material to test its response to stress (e.g., an
airplane wing). They can also be used to measure stress when
incorporated into an apparatus such as an electronic scale.
Strain gauges commonly function as a part or component of a
measuring or testing apparatus which converts the output signals
into an intelligible form. The strain gauges under consideration
are imported separate from the apparatus with which they
function.
ISSUE:
Are the strain gauges classified in Heading 9031 as
measuring or checking instruments not specified elsewhere, or in
Heading 8533 as resistors?
-2-
LAW AND ANALYSIS:
Heading 9031 describes measuring or checking instruments not
specified elsewhere in Chapter 90. The Explanatory Notes to
Heading 9031, p. 1531 provide that Heading 9031 covers electrical
instruments which measure stress and strain. However, the
Explanatory Notes at p. 1531 also provide that "...electrical
resistors known as 'strain gauges' fall in heading 85.33."
(emphasis in original). The strain gauges under consideration
cannot be classified in Heading 9031 because they are merely the
resistor component of measuring or testing apparatus and are
imported separate from the apparatus with which they function.
Heading 8533 describes electrical resistors other than
heating resistors. The Explanatory Notes to Heading 8533, p.
1385 provide that resistors are "...conductors whose function is
to provide a given electrical resistance in a circuit (e.g., to
limit the current flowing)." The strain gauges under
consideration test or measure physical stress by detecting the
increase in the metallic foil's electrical resistance which
results from the amount of stress applied; the articles
essentially rely on the phenomena of electrical resistivity and
are properly described as resistors. The articles are also
described in the Explanatory Notes to Heading 8533 by name; the
Explanatory Notes, p. 1386 provide that Heading 8533 includes
"[r]esistors known as 'strain gauges' being the sensitive
elements of a strain measuring instrument."
Unlike variable resistors with which one can adjust the
level of resistivity (e.g. rheostats), the strain gauges under
consideration are fixed resistors. Their resistance level is
predetermined and nonadjustable; their change in resistivity
results from the strain or stress being measured or tested. The
articles are fixed, non-carbon resistors classified in subheading
8533.21.00, HTSUSA.
HOLDING:
The strain gauges are classified in 8533.21.00, HTSUSA.
Sincerely,
John Durant, Director
Commercial Rulings Division