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There are different measurement methods (or techniques) incorporated in our almost unavoidable basic tools: LCR meters. As par example: Current-Voltage Methods, Bridge Methods, Differential Methods, Resonance Methods and derivatives from all those methods.
Deeply discussing all those methods is field of science, so we will left this (mostly mathematical) matter to scientist present at our forum. Here is important to know that using such different methods in practical LCR-Meters solutions, we cannot expect the same measuring results.
Here we intend to go through practical comparative test of different available LCR-meters with main interest in dependence of measurement results on the OPERATING (measurement) FREQUENCY (f).
As testing inductor was used unshielded PI coil model X30Z1 (including coil cable) wound along known basket way.
Main interest was in relationship of LCR-meters working frequency (f) and measured inductance (L) and of course comparison between measured results. With instruments which offers measurement of other inductor parameters (as par example: Q, R, DCR, Rs, Z) those parameters are noted too.
1. Let start with simple, but accurate enough for detector homebuilders LC-meter model VC6243+:
f=2.5kHz, L=222uH
2. Next was LC-meter with generic name L/C METER (instrument has no fixed frequency - it is adapted by uC to inductor properties):
f=271kHz, L=280uH
3. By uC controlled (and this way adapted working frequency) is Peak ATLAS LCR40 too:
f=200kHz, L=252uH, DCR=3,4E
4. LCR meter model 4070L is working at fixed frequency:
f=100Hz, L=280uH, R=4E
5. What to say about next "crazy meter" (mean that user become crazy using it). OK maybe it was something like interference with mains grid frequency, at those low working frequency, I don't know - I am using power supply (genuine), cause inner accu go dead. Deviations are smaller in case of regular "bundle" wound coil than in "basket" wound. This instrument offer to user himself, to change among four working frequencies. It is named TH 2821A LCR METER:
f=100Hz, L=123mH, R=3.3E, Z=3.3E, Q=0.043
f=120Hz, L=85mH, R=3.3E, Z=3.3E, Q=0.05
f=1kHz, L=1461uH, R=3.9E, Z=3.6E, Q=0.43
f=10kHz, L=242uH, R=65E, Z=14.8E, Q=4.3
6. Last tested LCR meter to user measurement at five working frequencies. Good design a lot of measurement parameters and most accurate from LCR-meters taken in test (and most expensive too).
It is about DER EE LCR METER DE-5000:
f=100Hz, L=230uH, Rs=3.35E, DCR=3.36E, Q=0.043
f=120Hz, L=230uH, Rs=3.35E, DCR=3.36E, Q=0.05
f=1kHz, L=230uH, Rs=3.36E, DCR=3.36E, Q=0.43
f=10kHz, L=230uH, Rs=3.36E, DCR=3.36E, Q=4.3
f=100kHz, L=234uH, Rs=3.90E, DCR=3.36E, Q=38
What to conclude from test comparison results?
We probably cannot exactly follow other member measurement data on coils, if we don't have exactly the same LCR meter.
If we avoid some "crazy" Tonghui models, we can easy survive in our MD DIY hobby, using one cheap and good model as par example VC6243+.
Deeply discussing all those methods is field of science, so we will left this (mostly mathematical) matter to scientist present at our forum. Here is important to know that using such different methods in practical LCR-Meters solutions, we cannot expect the same measuring results.
Here we intend to go through practical comparative test of different available LCR-meters with main interest in dependence of measurement results on the OPERATING (measurement) FREQUENCY (f).
As testing inductor was used unshielded PI coil model X30Z1 (including coil cable) wound along known basket way.
Main interest was in relationship of LCR-meters working frequency (f) and measured inductance (L) and of course comparison between measured results. With instruments which offers measurement of other inductor parameters (as par example: Q, R, DCR, Rs, Z) those parameters are noted too.
1. Let start with simple, but accurate enough for detector homebuilders LC-meter model VC6243+:
f=2.5kHz, L=222uH
2. Next was LC-meter with generic name L/C METER (instrument has no fixed frequency - it is adapted by uC to inductor properties):
f=271kHz, L=280uH
3. By uC controlled (and this way adapted working frequency) is Peak ATLAS LCR40 too:
f=200kHz, L=252uH, DCR=3,4E
4. LCR meter model 4070L is working at fixed frequency:
f=100Hz, L=280uH, R=4E
5. What to say about next "crazy meter" (mean that user become crazy using it). OK maybe it was something like interference with mains grid frequency, at those low working frequency, I don't know - I am using power supply (genuine), cause inner accu go dead. Deviations are smaller in case of regular "bundle" wound coil than in "basket" wound. This instrument offer to user himself, to change among four working frequencies. It is named TH 2821A LCR METER:
f=100Hz, L=123mH, R=3.3E, Z=3.3E, Q=0.043
f=120Hz, L=85mH, R=3.3E, Z=3.3E, Q=0.05
f=1kHz, L=1461uH, R=3.9E, Z=3.6E, Q=0.43
f=10kHz, L=242uH, R=65E, Z=14.8E, Q=4.3
6. Last tested LCR meter to user measurement at five working frequencies. Good design a lot of measurement parameters and most accurate from LCR-meters taken in test (and most expensive too).
It is about DER EE LCR METER DE-5000:
f=100Hz, L=230uH, Rs=3.35E, DCR=3.36E, Q=0.043
f=120Hz, L=230uH, Rs=3.35E, DCR=3.36E, Q=0.05
f=1kHz, L=230uH, Rs=3.36E, DCR=3.36E, Q=0.43
f=10kHz, L=230uH, Rs=3.36E, DCR=3.36E, Q=4.3
f=100kHz, L=234uH, Rs=3.90E, DCR=3.36E, Q=38
What to conclude from test comparison results?
We probably cannot exactly follow other member measurement data on coils, if we don't have exactly the same LCR meter.
If we avoid some "crazy" Tonghui models, we can easy survive in our MD DIY hobby, using one cheap and good model as par example VC6243+.
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