Author Topic: Q to Dave: why do you use Bob's ESR meter instead of Agilent LCR meter for caps?  (Read 7560 times)

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Offline Wartex

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Offline EEVblog

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I do not know how well the Agilent LCR meter works in-circuit.
Bob Parker's ESR meter I've had for years and is a known quantity.

Dave.
 

Offline robrenz

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Something to compare in your IET/Agilent LCR review  ;D ;D ;D

Online tom66

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Because most people can afford a $100 ESR meter, but not a $400 LCR meter?

*most people = myself
 

Offline Smokey

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Aren't all these LCR meters made from the same chip though?  You can get a Chinese meter with that chip for 150 USD.
 

Offline george graves

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I was looking on ebay - there some for $50.  Search for MESR-100.



Wonder how well it works?

Offline Wartex

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I do not know how well the Agilent LCR meter works in-circuit.
Bob Parker's ESR meter I've had for years and is a known quantity.

Dave.

thanks, makes sense
 

Offline Dread

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I guess that's the same reason I stick with fluke meters, they work well and I can trust the readings.
In the old days it was the same for my Simpson meter.
The Optimist says the glass is half full, the Pessimist says its half empty, an engineer only see's a glass that’s twice as big as it needs to be!
 

Offline ablacon64

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That's the most disturbing things of all, not being able to trust your equipment readings, I've been there, no money to get a decent equipment. Today I have the money (sort of.... hehhee) but don't buy state of the art equipment as well because I've learnt that pricey is not equal to better. In that case the ESR meter will do the same job, if not better/faster, than a 400% pricier LCR meter.
 

Offline robrenz

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I understand that many cannot afford a LCR meter.  I paid $335 for mine new from a US company and It does 100 to 100kHz frequency.
You get a lot of usefull other things for that extra money. Like higher resolution ESR readings at .001 Ohm resolution. plus all the other LCR features. Also is the cheapest high accuracy Milli Ohm meter you will find by using series ac resistance mode at low frequency. having the adjustable frequency can be important for ESR readings. not many LCR only meters have adjustable frequency.

My point is if you eventually plan on getting a LCR and you don't have a real burning need for a ESR only meter, save your money and get the LCR. It is a much more usefull instrument and can do the ESR equally well or better than a ESR only meter.

The $400.00 Agilent LCR has input protection and .0001 Ohm resolution compared to no input protection and .001 Ohm resolution of the $335.00 meter
« Last Edit: October 15, 2012, 11:26:38 am by robrenz »
 

Offline JoannaK

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Well, can't comment for Dave or others, but if I had like 400USD to spend, I'd rather get me Digital Scope and 50usd Esr meter than spend that money on the Aginet-LCR ..
 

Offline robrenz

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That would certainly be the right choices if you dont have a digital scope.

Offline kripton2035

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just saw that lcr meter from a french seller...
it is a 11000 pt meter, but it does the 100KHz freq test...
really cheap, and it must use the same chip as the others.
http://www.selectronic.fr/pont-de-mesure-rlc-metre-11000-points-doule-lcd.html

Offline robrenz

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All the buttons are there for all the functions that my meter has. If you are thinking of getting it you might want to see if they have test leads and tweezers that match the banana plug layout of the meter. You need to use all 4 leads for accurate measurements and the pairs should be shielded to the guard terminal which i dont see in the picture. it also does not have the typical slots for leaded components but that is not that big a deal.

Edit: the only accesories on the site are batteries but maybe the original manufacturer has accesories for it.

Edit2:  found on ebay and some of the pictures show accesories and the slots for leaded components
http://www.ebay.com/itm/Brand-CEM-9935-Professional-LCR-Digital-Multimeter-Safety-10-100KHz-L-C-R-D-Q-/280936728409?pt=LH_DefaultDomain_0&hash=item4169224759
« Last Edit: October 16, 2012, 08:29:43 pm by robrenz »
 

Offline casinada

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It clearly says Discharge capacitor before testing so it's not designed to do in circuit testing. Decent ESR meters are designed to do in circuit testing.
 ;D
 

Offline TriodeTiger

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It clearly says Discharge capacitor before testing so it's not designed to do in circuit testing. Decent ESR meters are designed to do in circuit testing.
 ;D

The ohms meter function does not work with an active voltage across the wire. Decent meters (such as the Agilent U1272A) have a "smart ohms" feature for active-circuit testing.
"Yes, I have deliberately traded off robustness for the sake of having knobs." - Dave Jones.
 

Offline robrenz

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It clearly says Discharge capacitor before testing so it's not designed to do in circuit testing. Decent ESR meters are designed to do in circuit testing.
 ;D

In circuit testing does not mean testing on a live circuit.
You should discharge the caps before testing on any meter.
Just because it says for in circuit testing does not mean you get an accurate reading. If two caps are in parallel in a circuit and you test one you are testing both together.

Offline flolic

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Hehe, just yesterday I accidentally discharged 200uF/400V capacitor through my homemade Russian "GO-ESR" meter without any consequences   :o

Only loud bang and some flashes...  ;D
« Last Edit: October 17, 2012, 12:52:36 pm by flolic »
 

Offline kripton2035

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the go-esr meter has 2 1n4007 diodes in parallel with the capacitor to test
so it seems a good protection for charged capacitors...
can add a small power resistor may be to avoid the "bang" ?


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