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Otto Wolff 5 Decade Wheatstone-Bridge
Description
The Unit is approx. 60x20x20cm in size and weights about 10kg. My unit has serial number 6577 and, according to this website, should date from 1930 or before. It's retail price in 1910 was 575.- Goldmark. As one Goldmark was then equivalent to 358g of Gold, this would have been equal to €7595.- today (2019).
Why would you buy/use this?
Because of the resistors age (and the build quality): Resistor values drift in the beginning due to oxidation. Over time the drift becomes less and the resistor “stabilizes”. At 90 years age I would expect the aging of the components to virtually halt, the oxidation process has come to an end. The only drift I'm expecting from it now is from temperature and, to a lesser extent, humidity. This is because the silk insulator of the manganin wires swells with humidity and minimally stretches the resistance wire.
So, basically I bought a bunch of high precision, ultra low drift, pre-aged resistors in a convenient box.
