§ 124 Patent Nickel.
Practically a copper nickel alloy, used to some extent by Siemens and Halske. It stands pretty well in the same relation to nickelin as the latter does to German silver. After annealing as for manganin it can be made into serviceable standards which do not change more than a few thousandths per cent. I have not come across a statement of its thermo-voltage against copper.
Another nickel copper alloy containing 50 per cent of each constituent. It appears to be a serviceable substance, having a temperature coefficient of 0.003 per cent per degree only, but an exceedingly high thermo-voltage, viz. 40 micro-volts per degree against copper.
| 1 German Silver. | 2 __________ 3 Nickelin made by Obermaier | 4 Rheo-tane. | 5 ___________6 Patent Nickel | 7. Manga-nese Copper. | 8. Nickel Manga-nese Copper. | |||
| Dia-meter 1.0 mm | Dia-meter 0.1 mm | Dia-meter 0.6 mm | Dia-meter 1.0 mm | |||||
| Copper | 60.16 | 61.63 | 54.57 | 53.28 | 74.41 | 74.71 | 70 | 73 |
| Zinc | 25.37 | 19.67 | 20.44 | 16.89 | 0.23 | 0.52 | ... | ... |
| Tin | ... | ... | ... | ... | trace | ... | ... | |
| Nickel | 14.03 | 18.46 | 24.48 | 25.31 | 25.10 | 24.14 | ... | 3 |
| Iron | 0.30 | 0.24 | 0.64 | 4.46 | 0.42 | 0.70 | ... | ... |
| Cobalt | trace | 0.19 | ... | ... | trace | trace | ... | ... |
| Mang-anese | trace | 0.18 | 0.27 | 0.37 | 0.13 | 0.17 | 30 | 24 |
| 99.86 | 100.37 | 100.40 | 100.31 | 100.24 | 100.24 | ... | ... | |
| Specific resist-ance | 30.0 | 33.2 | 44.8 | 52.5 | 34.2 | 32.8 | 100.6 | 47.7 |
| Temp-erature co-efficient | 0.00036 | 0.00030 | 0.00033 | 0.00041 | 0.00019 | 0.00021 | 0.00004 | 0.00003 |
The specific resistance is in “microhms, i.e. 10-6 ohms per cubic centimetre, and the temperature coefficient in degrees centigrade.
126. Nickel Manganese Copper. —
I can find no other reference with regard to this alloy mentioned by Lindeck. Nicholls, however (Silliman’s Journal [3], 39, 171, 1890), gives some particulars of alloys of copper and ferromanganese. The following table is taken from Wiedemann’s Beiblatter (abstract of Nicholl’s paper, 1890, p. 811). All these alloys appear to require annealing at a red heat before their resistances are anything like constant.
Let x be percentage of copper, then 100 — x is percentage of “ferromanganese.”
| Values of x. | 100 | 99.26 | 91.88 | 86.98 | 80.4 | 70.65 |
| Specific resistance with respect to copper (? pure) | 1 | 1.19 | 11.28 | 20.4 | 27.5 | 45.1 |
| Temperature coefficient per degree x 106 (hard) | 3202 | 2167 | 138 | 16 | 22 | -24 |
| Ditto (soft) | 184 | 80 | 66 | 21 |
If nickel is added, alloys of much the same character are obtained, some with negative temperature coefficients — for instance, one containing 52.51 per cent copper, 31.27 per cent ferromanganese, and 16.22 nickel.
A detailed account of several alloys will be found in a paper by Griffiths (Phil. Trans. 1894, p. 390), but as the constants were determined to a higher order of accuracy than the composition of the material — or, at all events, to a higher degree of accuracy than that to which the materials can be reproduced — there is no advantage in quoting them here.