Classification of oscilloscope depends on test circuit voltage, not supply voltage, under the Customs Tariff heading.

Classification under Heading 90.28(2) of the Customs Tariff depended on the voltage of the circuit whose electrical quantities the oscilloscope measured or checked, not merely the voltage of the supply circuit used to power the instrument. A distinction was drawn between the circuit in which the equipment operates as part of the functioning arrangement and the circuit actually being tested. Because the oscilloscope was used to test electrical quantities exceeding 400 volts, the lower input supply voltage did not disqualify it from the claimed heading, and it was held entitled to classification under Heading 90.28(2).

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Issues: Whether the imported oscilloscope was classifiable under Heading 90.28(2) of the Customs Tariff on the basis that it was designed for use in circuits exceeding 400 volts.

Analysis: The relevant criterion was held to be the voltage of the circuit whose electrical quantities the oscilloscope measures or checks, not merely the voltage of the supply circuit into which the instrument is plugged for operation. A distinction was drawn between the circuit of which the instrument becomes a part for functioning and the circuit in which it is actually used. Since the oscilloscope was used to test electrical quantities exceeding 400 volts, the lower input supply voltage did not disqualify it from the claimed heading.

Conclusion: The oscilloscope was entitled to classification under Heading 90.28(2) of the Customs Tariff.

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