EEVblog 1476 – Keithley 515A Wheatstone Bridge TEARDOWN & TUTORIAL

Teardown of the Keithley 515A Megohm Wheatstone bridge, plus a tutorial on how Wheatsone bridges work and their applications. Manual & Schematic: https://download.tek.com/manual/515A(Model515A).pdf
1960’s Daven precision resistor and attenuator catalog: http://www.technicalaudio.com/pdf/Daven/Daven_attenuator_switch_lab_Catalog.pdf

00:00 Keithley 515A Megohm Wheatstone bridge
03:50 – The Magic smoke test
04:00 – Zero check test
04:40 – Standardise calibration step
05:30 – Range calibration
06:21 – Measuring a 200M resistor
09:41 – Confirmation with a Keithley DMM7510 7 1/2 digit multimeter
10:37 – Weatstrong Bridge Tutorial
14:55 – Gaurd traces for high impedance measurement
16:22 – Teardown
28:25 – OUCH!

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