CLA-2-85:RR:NC:MM:109 R02730

Mr. Miles Hoehn
International Trade Compliance Manager
Therm-O-Disc, Inc.
1320 South Main Street
Mansfield, OH 44907

RE: The tariff classification of a flammable vapor sensor

Dear Mr. Hoehn:

In your letter dated October 25, 2005, you requested a tariff classification ruling.

The merchandise subject to this ruling is a flammable vapor sensor. It has a designated Model Number of 25VS. It is a carbon composition resistor. The 25VS sensor is comprised of three primary components; a sensor film, an insert-molded base, and a molded cover. The sensor film (a mixture of silicon and carbon) is deposited on the insert-molded base and shielded from the environment with a thermoplastic cover ultrasonically welded to the base. The carbon, which acts as a conductor, is dispersed throughout the silicon such that, in the absence of gasoline vapor, the carbon particles are in solid electrical contact. When the silicon encounters gasoline vapor, it expands, pulling some of the carbon particles apart, increasing the resistance of the sensor. The magnitude to which the resistance increases is dependent upon the gasoline vapor concentration; higher concentrations cause increased expansion of the silicon film, which results in a higher sensor resistance and vice versa.

The applicable subheading for the flammable vapor sensor (Model Number 25VS) will be 8533.40.8070, Harmonized Tariff Schedule of the United States (HTS), which provides for “Electrical resistors… other than heating resistors… parts thereof: Other variable resistors, including rheostats and potentiometers: Other: Other: Other.” The general rate of duty will be free.

This ruling is being issued under the provisions of Part 177 of the Customs Regulations (19 C.F.R. 177).

A copy of the ruling or the control number indicated above should be provided with the entry documents filed at the time this merchandise is imported. If you have any questions regarding the ruling, contact National Import Specialist Linda M. Hackett at 646-733-3015.

Sincerely,

Robert B. Swierupski
Director,
National Commodity
Specialist Division