. Electrical news and engineering . hat of the copper, thai is to say, if we have acircuit of 50 ohms R at 60 Kah., composed of a spool of wire 46ohms, and something else of 4 ohms, and if the tem|>erature risesso that the spool now has 47 ohms, then the R of this somethingelse must be 3 ohms if we wish to have the total R constant al 50ohms. In the Edison meter the resistance of the electrolytic cellsdecreases as the temperature increases, and lo make up for thedecrease in resistance a conqiensating spool of copper wire is putin series with same, which has an increasing resistance equal in
. Electrical news and engineering . hat of the copper, thai is to say, if we have acircuit of 50 ohms R at 60 Kah., composed of a spool of wire 46ohms, and something else of 4 ohms, and if the tem|>erature risesso that the spool now has 47 ohms, then the R of this somethingelse must be 3 ohms if we wish to have the total R constant al 50ohms. In the Edison meter the resistance of the electrolytic cellsdecreases as the temperature increases, and lo make up for thedecrease in resistance a conqiensating spool of copper wire is putin series with same, which has an increasing resistance equal inamount and opposite to that of the cell. In Fig. 3 it shows llieresistance of the bottle or electrolytic cell and also that of thecompensating spool. We see that the cell decreases and that thespool increases for increased temperature and that the two com-bined give us practically a straight line. The resistances arecalculated from 30 to 110 Fall, or a range of8o which is con-siderably more than is ever met with in practice. In the. Edison meter the branch of low resistance is made of and is called shunt. The resistance of German siKervaries .02 of 1% for every 1 Fah. In the smallest size of metersthe shunt has a resistance of .04 ohms at say 60 .and we have nocompensating devices, therefore for a rise in temperature we musthave an increase in resistance, and if we have an increase in re-sistance an error must be the result. The greatest percentage ofthe error will he in the smallest meter, therefore we will just cal-culate wh;it the error amounts 10. .At 60 the shunt is .04 ohms,at los it is .04040 ohms and al 30 it is .039733 or a differencebetween 30 and 105 of .000667 ohms making the errorthat can come into effect less than 2% or lo be exact ,.. or lessthan \\ above and less than 1% below. T;iking the conductivities we find that if too amjieres are flow-ing in the circuits .0S161225 amperes go through the bottle at \t los there are .082248 am
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