Products > Test Equipment
Best CHEAP LCR meter for small capacitors and inductors?
precaud:
--- Quote from: mawyatt on February 11, 2023, 03:39:02 pm ---We don't have a XJW01 but this statement doesn't make sense??
The test leads/tweezer are "part of the DUT measurement", whatever they are. The only way to remove the test lead measurement effects is to include them in the Open/Short calibration routines.
--- End quote ---
Yes, but the calibration procedure and the Open/Short compensation math are not the same. If you cal the unit at the BNC's, then the Open/Short math can properly do what it is designed to do; counteract for the impedance of the fixtures/leads.
If you cal the unit with a set of leads, then the Open/Short correction is effectively bypassed.
Try it.
mawyatt:
--- Quote from: precaud on February 11, 2023, 06:41:48 pm ---
--- Quote from: mawyatt on February 11, 2023, 03:39:02 pm ---We don't have a XJW01 but this statement doesn't make sense??
The test leads/tweezer are "part of the DUT measurement", whatever they are. The only way to remove the test lead measurement effects is to include them in the Open/Short calibration routines.
--- End quote ---
Yes, but the calibration procedure and the Open/Short compensation math are not the same. If you cal the unit at the BNC's, then the Open/Short math can properly do what it is designed to do; counteract for the impedance of the fixtures/leads.
If you cal the unit with a set of leads, then the Open/Short correction is effectively bypassed.
Try it.
--- End quote ---
As mentioned we don't have a XJW01, so can't give it a try!!
Edit: Rereading this, does the XJW01 have a separate Calibration to the instrument BNCs, then another Open/Short Calibration/Correction for the test leads/fixture effects? If true then we need to reword the stuff within the "" quotes below.
"If you just cal to the instrument BNC connectors, then how is one expecting an accurate DUT result with an external fixture and/or test leads? How does the instrument know what the external leads/fixture represent? Not sure how this "math" works even with perfect Kelvin leads regarding capacitive/inductive measures where phase shift comes into play?
Does the instrument not allow cal with external leads/fixture (does it sense this somehow?), and how does it establish a Short reading, as a short between HC and LC, or HC to HP then to LC to LP? Curious as to how this and the cal math works?"
The DE-5000 we have does allow Open/Short calibration with external fixture/leads at the fixture/leads, not at the instrument interface.
Anyway, interested to understand how this calibration & math works?
Best,
precaud:
Open/Short compensation is NOT calibration.
It compensates for the affects of test fixtures and leads.
HP's Impedance Masurement Handbooks discuss this in detail.
mawyatt:
Whatever you want to call it.
The DE-5000 this is referred to as "CALibration", the TH2830 calls it "CORRection", Hioki calls is "ADJUSTMENT", suspect other LCR OEMs might call it Compensation!!
So take your pick :-+
Best,
precaud:
Look at the underlying concepts instead of getting caught in the semantics.
There are two of them, so best we use different words for them.
If we can't agree on language, not much of a discussion is possible.
I am using Calibration to refer to the adjustment of the machine to its stated accuracy at its connectors.
I am using Compensation to refer to the procedure that extends that accuracy to the measurement point of a fixture or the end of test leads.
They are not the same process. I doubt the internal math is the same for them, either.
All I'm saying is, using the words as defined above, don't Calibrate any LCR meter using test leads.
Calibrate it at its connection terminals. and then use Open/Short Compensation (or OSL if available) for whatever leads or fixture used.
This is just common sense.
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