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Unformatted text preview: R m = internal resistance of measuring volt meter (input impedance), E = measured voltage). Now, the current from the voltage source is = = + + I EiRequiv EiR2 R1RmR1 Rm . As = -E0 Ei IR2 , = + + E0Ei 11 R2R11 R1Rm . For R m = , = + E0Ei R1R1 R2 . The difference between these two values is the loading error due to a finite R m . For R m = , the loading error is 0. Consider an example with a Wheatstone bridge, whose 4 arms correspond to strain gauges. 28...
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This note was uploaded on 05/04/2010 for the course CEE 291 taught by Professor Hoopes during the Spring '10 term at Wisconsin.
- Spring '10