“4. Thermal radiation is energy emitted from the surface of an object which is due to the object’s temperature above absolute [zero] which is -273ºC or -460ºF. Hot objects emit more energy than cold objects. 5. Thermography, according to Flir Systems, is the science of acquisition and analysis of thermal information from non-contact thermal imaging devices. The energy from an object is radiated at different levels across the electromagnetic spectrum of which infrared is a part. The infrared region can be sub-divided into two regions (in which Flir manufacture equipment for the thermography market): the mid-band is concerned with infrared spectrums from 3 to 5 microns … while the long wave ranges from 8 to 12 microns … . The majority of Flir cameras fall into the latter part of the infrared spectrum with the cameras that make up this appeal falling into the long wave.”
“2.10 … Heat energy from the target is focussed via the lens onto the heat sensitive detector. The field of view enlarges as the distance between the camera and the target increases. Thus the further the distance between the thermometer and the target the larger will be the size of the target. The output of the array is fed into an amplifier system. The output can be used to detect heat, measure temperature, to monitor temperature (over a period of time) or as part of a temperature control system. 2.11 The Flir images are really an extension of this principle with the single detector replaced by a two-dimensional detector array. This allows a thermal “image” to be produced. 2.12 All of the Flir products are infrared imagers which have the ability to display the temperature [with one exception which was not in dispute]. All are based on similar technology. 2.13 All of the imagers work in a non-contact mode. Essentially, the instruments work in a similar manner to a digital camera in the sense that there is a lens system which focuses the image on to an energy sensitive array. However, in a digital camera it is light which is being focused onto a light sensitive array whereas in the Flir cameras it is radiated energy in the form of heat which is being focused onto a heat sensitive array. 2.14 The image produced by a digital camera is an image, which can be in colour or black and white, which represents the view of the subject scene when the photograph was taken. By comparison, the image produced by the Flir imagers is a thermal image of the subject scene. The image has to be generated from the temperature data obtained from the sensor array. [He then explains how a range of colours is used to represent different temperatures]. The end result is usually an image where the colour tones can have some similarities with a light image. For example, the image formed by heat radiated by a person will be in the general form of that person’s body and can be recognised as such by a person viewing the thermal image. … 2.16 All objects which are at a temperature above absolute zero (-273ºC) radiate energy in the infrared spectrum. The amount of heat radiated will be in proportion to the absolute temperature (-273ºC). There is a small adjustment necessary depending on the material and the colour. A black body will radiate the most heat. The Flir imagers (as do other makes of imaging cameras) have an in-built offset capability to take account of this. This is called the emissivity. 2.17 All of the Flir imagers are powered by battery which is contained in the handgrip. The batteries can be charged in the camera or removed and charged externally. 2.18 Each of the Flir imagers has the ability to store a number of images which have been taken (like a photograph except that it is a thermal image). Each image will have a colour scale representing temperature. The high and low points of each image will depend on the range of temperatures in the image. Thus, when comparing images it is important to remember that a particular colour does not necessarily represent the same temperature. 2.19 Each imager, [with the one exception which was not in dispute], has the capability to make a temperature measurement which is then displayed on the LCD display. The temperature measurement is based on a small area in the centre of the image and is the average temperature of the pixels contained in that area. 2.20 The imager cannot take normal pictures. It can only take infrared pictures.”
“We find the question whether the Products are “instruments and apparatus for measuring or checking quantities of heat” more difficult. This refers to quantities of heat, sound or light. As a scientific matter we would follow Mr Clues’ evidence that the “quantity of heat” is a measure of energy and is measured in calories or joules; the Products do not measure this, as a calorimeter does. Measuring a quantity of heat would imply measuring the resulting change in temperature, rather than temperature itself. The quantity of sound could be the frequency (pitch) or the loudness, which corresponds to the brightness of light. The quantity of light is strictly the rate of flow of light from a source but exposure meters are listed in the heading (and photometers and luxmeters are mentioned in the HSEN), which measure the intensity of light, which must therefore qualify as a quantity of light. The actual readings of the values for heat, light and sound are delivered in modern instruments from a measurement of radiation of energy which is converted by the instrument into an absolute value in its read-out in the same way as the Products. We are not therefore convinced that we should follow scientific precision here any more than being concerned whether an instrument recording an infra-red radiation picture is a camera.” [They then referred to an earlier Tribunal decision in which the concept of “measuring and checking” had been elucidated, in relation to measuring and checking electrical quantities in heading 9030, as involving the determination of quantity expressed as a figure (measuring) and something which gives either a yes or no result, such as whether current is passing (checking)]. “The Products express as a figure a quantity of heat in the non-scientifically strict sense of the amount of radiation from the target expressed as a temperature, which is analogous to what an exposure meter does. We also consider that they do check a quantity of heat in the sense of whether heat is being radiated or not, and by setting the span, whether the temperature is above or below a set figure or within a range as small as 4ºC. Accordingly the Products also fall within this heading.”
“(h) Hydrometers, thermometers, hygrometers and similar instruments of heading 9025, whether or not for use in laboratories.”
“The electromagnetic spectrum is divided arbitrarily into a number of wavelength regions, called bands, distinguished by the methods used to produce and detect the radiation. There is no fundamental difference between radiation in the different bands of the electromagnetic spectrum. They are all governed by the same laws and the only differences are those due to differences in wavelength.”