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Teledeltos paper is an electrically conductive paper. It is formed by a coating of carbon on one side of a sheet of paper, giving one black and one white side. Western Union developed Teledeltos paper in the late 1940s for use in spark printer based fax machines and chart recorders.〔Grosvenor Hotchkiss, (Electrosensitive Recording Paper for Facsimilie Telegraph Apparatus and Graphic Chart Instruments ), (Western Union Technical Review, Vol. 3, No, 1 ) (January 1949); page 6.〕 Teledeltos paper has several uses within engineering that are far removed from its original use in spark printers. Many of these use the paper to model the distribution of electric and other scalar fields. == Use == Teledeltos provides a sheet of a uniform resistor, with isotropic resistivity in each direction. As it is cheap and easily cut to shape, it may be used to make one-off resistors of any shape needed. The paper backing also forms a convenient insulator from the bench. These are usually made to represent or model some real-world example of a two-dimensional scalar field, where is it is necessary to study the field's distribution. This field may be an electric field, or some other field following the same linear distribution rules. The resistivity of Teledeltos is around 6 kilohms / square.〔 This is low enough that it may be used with safe low voltages, yet high enough that the currents remain low, avoiding problems with contact resistance. Connections are made to the paper by painting on areas of silver-loaded conductive paint and attaching wires to these, usually with spring clips.〔 Each painted area has a low resistivity (relative to the carbon) and so may be assumed to be at a constant voltage. With the voltages applied, the current flow through the sheet will emulate the field distribution. Voltages may be measured within the sheet by applying a voltmeter probe (relative to one of the known electrodes) or current flows may be measured. As the sheet's resistivity is constant, the simplest way to measure a current flow is to use a small two-probe voltmeter to measure the voltage difference between the probes. As their spacing is known, and the resistivity, the resistance between them and (by Ohm's law) the current flow can be easily determined. An assumption in some cases is that the surrounding field is 'infinite', this would also require an infinite sheet of Teledeltos. Provided that the sheet is merely 'large' in comparison to the experimental area, a sheet of finite size is sufficient for most experimental practice.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Teledeltos」の詳細全文を読む スポンサード リンク
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