CLA-2 CO:R:C:M 957510 DWS
Ms. Sandy M. Rickert
E. Besler & Company
P.O. Box 66361
Chicago, IL 60666-0361
RE: Photosensors; Safety Light Curtains; Optical Coupled Sensors;
Explanatory Notes 85.41(B) and (C); HQ 088341; Chapter 85,
Note 5; 8536.50.80
Dear Mr. Rickert:
This is in response to your letter of August 26, 1994, on behalf of Micro Switch, to the Area
Director of Customs, New York Seaport, concerning the classification of photoelectric sensors
and safety light curtains under the Harmonized Tariff Schedule of the United States (HTSUS).
We have also considered information provided in a letter dated November 4, 1994, from Micro
Switch, in preparing this ruling.
FACTS:
The merchandise consists of photoelectric sensors and safety light curtains. It is our
understanding that both items operate in a similar manner. Each consists of a light emitting diode
(LED) and a photo darlington transistor. Both of these components are mounted so that the light
emitted by the LED is directed at the surface of the photo darlington transistor. This
configuration allows a target to be detected when the LED light path is interrupted. The
photosensor will respond to a target's presence or absence using either digital or analog
intelligence to perform such functions as positioning, switching, measuring, and/or diagnostics.
The safety light curtain will react to the interruption of the LED light path by shutting down a
power driven machine in which it is contained to protect the machine's operator.
The subheadings under consideration are as follows:
8536.50.80: [e]lectrical apparatus for switching or
protecting electrical circuits, or for
making connections to or in electrical
circuits (for example, switches, relays, fuses,
surge suppressors, plugs, sockets, lamp-
holders, junction boxes), for a voltage not
exceeding 1,000 V: [o]ther switches: [o]ther.
The general, column one rate of duty for goods classifiable
under this provision is 4.8 percent ad valorem.
8541.40.80: . . . : [p]hotosensitive semiconductor devices,
including photovoltaic cells whether or not
assembled in modules or made up into panels;
light-emitting diodes: [o]ther: [o]ptical
coupled isolators.
Goods classifiable under this provision receive duty-free
treatment.
ISSUE:
Whether the photoelectric sensors and the safety light curtains are classifiable under
subheading 8536.50.80, HTSUS, as other electrical apparatus for switching electrical circuits, or
under subheading 8541.40.80, HTSUS, as optical coupled isolators.
LAW AND ANALYSIS:
Classification of merchandise under the HTSUS is in accordance with the General Rules of
Interpretation (GRI's).
GRI 1 provides that classification is determined according to the terms of the headings and any
relative section or chapter notes.
In understanding the language of the HTSUS, the Harmonized Commodity Description and
Coding System Explanatory Notes may be utilized. The Explanatory Notes, although not
dispositive or legally binding, provide a commentary on the scope of each heading of the HTSUS,
and are generally indicative of the proper interpretation of these headings. See T.D. 89-80, 54
Fed. Reg. 35127, 35128 (August 23, 1989). In part, Explanatory Notes 85.41(B) and (C) (pp.
1398 - 1399) states that:
(B) PHOTOSENSITIVE SEMICONDUCTOR DEVICES
This group comprises photosensitive semiconductor devices in
which the action of visible rays, infra-red rays or ultra-
violet rays causes variations in resistivity or generates
an electromotive force, by the internal photoelectric
effect. . .
The main types of photosensitive semiconductor devices are:
(1) xxx
(2) Photovoltaic cells, which convert light directly into
electrical energy without the need for an external
source of current. Photovoltaic cells based on
selenium are used mainly in luxmeters and exposure
meters. Those based on silicon have a higher output
and are used, in particular, in control and regulating
equipment, for detecting light impulses, in
communication systems using fibre optics, etc.
Special categories of photovoltaic cells are:
(i) xxx
(ii) Photodiodes (germanium, silicon, etc.),
characterised by a variation in resistivity when
light rays strike their p n junction. They are
used in automatic data processing (reading of
punched cards and tapes, data storage), as
photocathodes in certain electronic tubes, in
radiation pyrometers, etc. Phototransistors and
photothyristors belong to this category of
photoelectric receivers. . .
(iii) Photocouples and photorelays consisting of
electroluminescent diodes combined with
photodiodes, phototransistors or photothyristors.
Photosensitive semiconductor devices fall in this heading
whether presented mounted (i.e., with their terminals or
leads), packaged or unmounted.
(C) LIGHT EMITTING DIODES
Light emitting diodes, or electroluminescent diodes,
(based, inter alia, on gallium arsenide or gallium
phosphide) are devices which convert electric energy into
visible, infra-red or ultra-violet rays. They are used,
e.g., for displaying or transmitting data in control
systems.
In HQ 088341, dated February 26, 1991, we held that photosensors, similar to the subject
merchandise, were classifiable under subheading 8541.40.80, HTSUS. In that ruling, we stated
that:
[t]he photosensor at issue consists of a LED and photo-
transistor combined together as one unit. An LED is
described with electroluminescent diodes as devices which
convert electric energy into visible, infra-red or ultra-
violet rays. EN 85.41(C). A phototransistor is described
as a type of photoelectric receiver characterized by a
variation in resistivity when light rays strike its p n
junction. EN 85.41(B)(2)(ii). The phototransistor at issue
operates by receiving rays from the LED which create a
variation in resistivity. When these rays are interrupted,
by a shaft or key in some cases, this variation in
resistivity ceases. Accordingly, the photosensor satisfies
the description of a photosensitive semiconductor device
consisting of an electroluminescent diode combined with a
phototransistor.
Subheading 8541.40.80, HTSUS, provides for optical coupled
isolators. These are described as very small four-terminal
electronic circuit elements that include in an integral
package a light emitter and light detector. McGraw-Hill
Encyclopedia of Science and Technology (MH) (6th ed.),
vol. 12, p. 419 (1987). The optical emitters most commonly
used in an isolator are LEDs. MH at 419. As stated
previously, the photosensor contains a LED. A type of light
detector used in isolators are light-sensitive devices that
modify a voltage or current such as phototransistors. MH at
419. As stated previously, the subject photosensor contains
a phototransistor. Furthermore, a LED-silicon detector
combination is cited as a type of optical coupled isolator.
MH at 419. A photo-darlington sensor is cited as a type of
light detector used in a LED-silicon detector. MH at 420. Accordingly, the photosensor
satisfies the description of an optical coupled isolator.
It is our position that, as with the photosensors in HQ 088341, the subject photoelectric
sensors and the safety light curtains are classifiable under subheading 8541.40.80, HTSUS, as
optical coupled isolators. In an optical isolator, the emitting and detecting devices are so
positioned that the majority of the emission from the emitter is optically coupled to the light-sensitive area of the detector. This configuration uses an electronic input signal to cause an
electronic input signal without any electronic connection between the input (LED) and the output
(phototransistor) terminals. The subject merchandise satisfies this description. It is our
understanding that both the photoelectric sensors and the safety light curtains are configured in
such a way that the light emitted by the LED is optically coupled to the light-sensitive area of the
photo darlingtion transistor. When the rays emitted by the LED are broken by a target, the
isolator is no longer coupled and does not produce an output signal. In addition, no electrical
connection exists between the LED and photo darlington transistor within the merchandise.
Therefore, based upon the information you have submitted, the merchandise satisfies the
descriptions of how an optical coupled isolator functions.
Consideration was given to classification of the merchandise under subheading 8536.50.80,
HTSUS, as other electrical apparatus for switching electrical circuits. However, as we stated in
HQ 088341, the merchandise does not meet any of the technical descriptions of switches, nor is
the merchandise similar to any of the exemplars listed under Explanatory Note 85.36.
In part, chapter 85, note 5, HTSUS, states that:
[f]or the classification of the articles defined in this
note, headings 8541 and 8542 shall take precedence over any
other heading in the tariff schedule which might cover them
by reference to, in particular function, their function.
Even if the photoelectric sensors and the safety light curtains were described under heading
8536, HTSUS, based upon chapter 85, note 5, HTSUS, classification of the merchandise under
heading 8541, HTSUS, would take precedence over classification under heading 8536, HTSUS.
Therefore, the merchandise is classifiable under subheading 8541.40.80, HTSUS, as optical
coupled sensors.
HOLDING:
The photoelectric sensors and the safety light curtains are classifiable under subheading
8541.40.80, HTSUS, as optical coupled sensors.
Sincerely,
John Durant, Director
Commercial Rulings Division