Customs exemption for thermometers and pyrometers limits payable duty to an established ad valorem ceiling on import. Exempts imports of thermometers and pyrometers classified under sub headings 9025.11 and 9025.19 from customs duty insofar as such duty exceeds 40 per cent ad valorem, limited to instruments not combined with other apparatus, pursuant to a notification issued under the Customs Act; the exemption takes effect on 1 January 1992.