Composite equipment classification follows the principal function of an integrated system, not a separate heading for an accessory monitor.

Composite equipment is classified by its principal function where separately identifiable components operate only as part of an integrated system. A colour monitor used with a thermal imager did not function independently and worked only to record and analyse temperature data within the same system. On that basis, the integrated thermal imager system was held to fall under Heading 9027.50, and separate classification of the monitor under Heading 8521.90 was not warranted.

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Issues: Whether the colour monitor imported as part of the thermal imager system was correctly classified with the thermal imager under Heading 9027.50 of the Customs Tariff Act, 1975, or was separately classifiable under Heading 8521.90.

Analysis: The classification turned on the application of the Section and Chapter Notes governing composite and multi-purpose equipment, including the principle that complementary functions of separately identifiable accessories are to be treated with the component performing the principal function. The record showed that the monitor did not operate independently but worked only as part of the thermal imager system for recording and analysing temperature data, and the components together performed the common function of thermal measurement. In that setting, the more specific classification applicable to the integrated system was preferred over a separate general classification for the monitor.

Conclusion: The colour monitor was correctly classified along with the thermal imager under Heading 9027.50, and separate classification under Heading 8521.90 was not warranted.

Final Conclusion: The classification adopted by the appellate authority was upheld, and the revenue challenge to treating the monitor as part of the thermal imager system failed.

Ratio Decidendi: Where components are complementary and function together as an integrated system for a principal purpose, classification follows the principal function of the system rather than a separate heading for an accessory or sub-component.

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