MIT Measurement Lab resistance standards

I obtained these resistance standards from the MIT lab clean-out a number of years ago.

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They are marked “MEAS LAB”, which I presume stands for “Measurement Laboratory”. This is the 2,000,000 Ohm standard.

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I also obtained this 1,000,000 Ohm standard.

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They are rather an odd puzzle. The enclosure looks like typical General Radio construction …

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… with splined miter joints, beading at the top edge, and a hand-rubbed French polish finish on the New England walnut.

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On the other hand, the resistors are Shallcross wire-wound ceramic core resistors, not General Radio mica card resistors.

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This is the 2,000,000 Ohm resistor.

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This is the 1,000,000 Ohm resistor.

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The Shallcross resistors have drifted a bit over time, or they weren’t that accurate to begin with. The 2M Ω resistor measures about 2,0170,000 Ohms on my HP 3456A.

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The 1M Ω resistor is closer, at about 1,007,440 Ohms.

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I think they must have been lab-made. Aside from the Shallcross resistors, the Micarta tops also don’t have any General Radio markings. Perhaps they acquired a few enclosures from the General Radio plant a few blocks up the street?

© Steve Byan 2011-2019