9027: Instruments and apparatus for physical or chemical analysis (for example, polarimeters, refractometers, spectrometers, gas or smoke analysis apparatus); instruments and apparatus for measuring or checking viscosity, porosity, expansion, surface tension or the like; instruments and apparatus for measuring or checking quantities of heat, sound or light (including exposure meters); microtomes

1. For the purposes of subheadings 90153010, 90258040, 90261021, 90261029, 90262020, 90268020, 90271010 and 90321020, the expression ‘electronic’ means instruments and apparatus which incorporate one or more articles of heading 8540, 8541 or 8542 but for the purposes of the foregoing, no account shall be taken of articles of heading 8540, 8541 or 8542 which have solely the function of rectifying current or which are included in the power pack of instruments or apparatus.

2. For the purposes of subheading 90211010, the expression "orthopaedic appliances" means appliances which are specially designed for a particular orthopaedic purpose, in distinction to products that might be used for various purposes (for example, products for overstrained joints, ligaments or tendons caused by sporting activities, type writing, and products which simply alleviate pain in the defective or disabled part of the body, for example, caused by inflammation).

The "orthopaedic appliances" must completely prevent a specific movement of the defective or disabled part of the body (for example, joints, ligaments, tendons) in order to exclude further injuries or bodily deformities or an aggravation of such injuries or deformities, as distinct from other products that cannot prevent specific movements, yet prevent reflex movements (movements carried out subconsciously) through the relative inflexibility of those products due to, for example, flexible splints, pressure pads, non-elastic textile material, restrictions through "Velcro-type" straps.