Electricity measuring

In another type of measurement, the parallel between mechanical and electrical networks can be exploited by using variable capacitors and resistors to balance the impedance of the transducer circuit. These electrical measurements readily lend themselves to computer interfacing for data acquisition and analysis. 

Other methods attempt to probe the stmcture of the foam indirectly, without directly imaging it. Eor example, since the Hquid portion of the foam typically contains electrolytes, it conducts electrical current, and much work has been done on relating the electrical conductivity of a foam to its Hquid content, both experimentally (15) and theoretically (16). The value of the conductivity depends in a very complex fashion on not only the Hquid content and its distribution between films and borders, but the geometrical stmcture of the bubble packing arrangement. Thus electrical measurements offer only a rather cmde probe of the gas Hquid ratio, a quantity that can be accurately estimated from the foam s mass density. 

Golding, E.W., Electrical measurements and measuring Instruments. The English Language Book Socieiy and Sir Isaac Pitman Sons Ltd, London. 

The indicating instruments used for electrical measurements must conform to lEC 6005 I and have the following aectiracies ... 

M to 9 Direct acting indicating analogue electrical measuring instruments and their accessories 1248 1 to 9 BS 89-1 to 9 ... 

Direct acting recording electrical measuring instrument and their accessories - BS 90/1993 -... 

Yakushev, V.V. (1978), Electrical Measurements in a Dynamic Experiment, Fiz. Go-reniya Vzryva 14, 3-19. 

Field coating of welds has always presented problems. Straw and jute with a greasy material was employed in 1910, but this later saponified in the soil. By chance the pharmacist Schade of Berlin learned of this problem and recommended the use of petroleum jelly in a bandage-like application. Hot-applied bitumen bands, as used by pipe works since 1928. proved to be most durable. Since 1930, electrical measuring methods have played an important part in research into insulation bands and pipe coverings carried out by the Gas Institute in Karlsruhe, the present-day Engier-Bunte Institute 18). 

In all electrical measurements, current and voltage measuring instruments with two terminals are employed. The object being measured similarly has two termi-... 

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