Timeline for How precise is a DVM input impedance for high-Z circuit measurements?
Current License: CC BY-SA 4.0
4 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| yesterday | comment | added | Spehro 'speff' Pefhany | @Joe Your instincts are good. It's not silly to think about it. If the test voltage from the Fluke was high enough to drive the other over range to the point where some kind of (nonlinear) internal clamping took place you could get an inaccurate (low) reading. But that's not at all likely the way DMMs are actually designed and if the voltage meter is not reading over range during the test then it should not be clamping. | |
| yesterday | vote | accept | Joe | ||
| yesterday | comment | added | Joe | Thanks speff, that works. I don't know why I assumed that the test voltage would foul things somehow. Turns out the input impedance of all my meters is over 10% higher than specified at 11.12 Meg. One day I'll get proper equipment.... | |
| yesterday | history | answered | Spehro 'speff' Pefhany | CC BY-SA 4.0 |