 | American Institute of Mining Engineers - 1885 - 918 pages
...over all of the other systems, which require that the ore must be rolled before a sample can be taken. The two machines are driven at different speeds, to prevent any possible error which might arise from isochronal motion. In testing these machines by re-sampling various lots of... | |
 | John Mitchell (F.C.S.) - Assaying - 1888 - 1002 pages
...parcel is usually quite sufficient ; though in exceptional cases, 15 per cent, of 30 per cent., or 4^ per cent, of the ore may be required. The two machines...limit of error has been found less than one-fourth of 1 per cent. ; while even the best handsampling may vary 2 per cent. The fact that the division is one... | |
 | Park Benjamin - Machinery - 1892 - 962 pages
...elevated, and again reduced by dropping through another spout equipped with a sampler of the same design. The two machines are driven at different speeds to prevent any possible error that Flo. 1. — Bnmton's automatic sampler. might result from isochronal motion. Experience has shown that... | |
 | Park Benjamin - Machinery - 1892 - 970 pages
...eleva*-0 and again reduced by dropping through another spout equipped with a sampler of the design. The two machines are driven at different speeds to prevent any possible error might result from isochronal motion. Experience has shown that 10 percent, of 20 per cent., or 2 per... | |
 | Edward Dyer Peters - Copper - 1898 - 742 pages
...machine, from which the final sample drops into a locked bin, to be pulverized and quartered by hand. The two machines are driven at different speeds, to prevent any possible error that might rise from isochronal motion. A still more recent invention of Mr. Brun^on's is the quartering shovel,... | |
| |
... though in exceptional cases, 15 per cent, of 30 per cent., or 4^ per cent, of the ore may be required. 