Products > Test Equipment
LCR meter opinion
TimFox:
--- Quote from: nctnico on January 26, 2022, 09:33:38 pm ---
--- Quote from: Martin72 on January 26, 2022, 09:25:59 pm ---@nctnico:
--- Quote ---That doesn't matter. The readings should still agree.
--- End quote ---
Agree to what ?
--- End quote ---
Between eachother. All LCR meters measure the capacitance at a given frequency. So in whatever way the DUT is affected by the frequency, they should read the same value (within their accuracy specification).
--- End quote ---
My point is that the change in measured capacitance is affected by the fixturing (including clips and lead length) and short-circuit calibration, which can differ slightly between LCR meters.
Martin72:
Yes, therefore I will bring the three on the nearest level when doing the next measures.
Actually, the keysight got short 2-wire alligator clips.
DE5000 got short 4-wire alligator clips and ST2830 4-wire kelvin clips.
But all got these "direct" terminals (ST2830 a fixture for this), next time I´ll use these ones, when the cap allow it.
TimFox:
Pay special attention to the connections for "short" calibration, to ensure that they are very equivalent to each other to get a repeatable parasitic inductance (outside of the internal inductance of the capacitor).
It might be better to use a very short piece of medium-heavy copper wire between the clips, rather than connect the clips to each other directly.
Martin72:
Will have it in mind.
Interesting thing:
chinese bench lcr
mawyatt:
--- Quote from: TimFox on January 26, 2022, 10:09:58 pm ---Pay special attention to the connections for "short" calibration, to ensure that they are very equivalent to each other to get a repeatable parasitic inductance (outside of the internal inductance of the capacitor).
It might be better to use a very short piece of medium-heavy copper wire between the clips, rather than connect the clips to each other directly.
--- End quote ---
Agree, this is the inductive equivalent of removing the few femto farads from the test fixture. A small piece (20mm x 10mm x 3mm) of solid copper sheet works well as a good inductive & resistive shunt.
Best,
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