Q to Dave: why do you use Bob's ESR meter instead of Agilent LCR meter for caps? - Page 1
Forum section: electronics / general

author: Wartex
author_rank: Frequent Contributor
timestamp: October 14, 2012, 09:35:00 pm
content: subj

author: EEVblog
author_rank: Unknown
timestamp: October 14, 2012, 10:44:26 pm
content: 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.

author: robrenz
author_rank: Super Contributor
timestamp: October 14, 2012, 11:33:16 pm
content: Something to compare in your IET/Agilent LCR review

author: tom66
author_rank: Super Contributor
timestamp: October 14, 2012, 11:44:15 pm
content: Because most people can afford a $100 ESR meter, but not a $400 LCR meter?*most people = myself

author: Smokey
author_rank: Super Contributor
timestamp: October 14, 2012, 11:54:00 pm
content: Aren't all these LCR meters made from the same chip though? You can get a Chinese meter with that chip for 150 USD.

author: george graves
author_rank: Super Contributor
timestamp: October 15, 2012, 12:33:45 am
content: I was looking on ebay - there some for $50. Search for MESR-100.Wonder how well it works?

author: Wartex
author_rank: Frequent Contributor
timestamp: October 15, 2012, 01:03:27 am
content: Quote from: EEVblog on October 14, 2012, 10:44:26 pmthanks, makes sense

author: Dread
author_rank: Regular Contributor
timestamp: October 15, 2012, 01:21:29 am
content: 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.

author: ablacon64
author_rank: Frequent Contributor
timestamp: October 15, 2012, 02:39:29 am
content: 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.

author: robrenz
author_rank: Super Contributor
timestamp: October 15, 2012, 03:57:44 am
content: 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 arealburning 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

author: JoannaK
author_rank: Frequent Contributor
timestamp: October 16, 2012, 07:13:57 pm
content: 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 ..

author: robrenz
author_rank: Super Contributor
timestamp: October 16, 2012, 07:27:26 pm
content: That would certainly be the right choices if you dont have a digital scope.

author: kripton2035
author_rank: Super Contributor
timestamp: October 16, 2012, 08:10:23 pm
content: 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

author: robrenz
author_rank: Super Contributor
timestamp: October 16, 2012, 08:21:20 pm
content: 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 andsomeof the pictures show accesories and the slots for leaded componentshttp://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

author: casinada
author_rank: Frequent Contributor
timestamp: October 17, 2012, 05:37:32 am
content: 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.

author: TriodeTiger
author_rank: Regular Contributor
timestamp: October 17, 2012, 07:01:04 am
content: Quote from: casinada on October 17, 2012, 05:37:32 amThe 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.

author: robrenz
author_rank: Super Contributor
timestamp: October 17, 2012, 11:14:07 am
content: Quote from: casinada on October 17, 2012, 05:37:32 amIn 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.

author: flolic
author_rank: Frequent Contributor
timestamp: October 17, 2012, 11:53:27 am
content: Hehe, just yesterday I accidentally discharged 200uF/400V capacitor through my homemade Russian "GO-ESR" meter without any consequencesOnly loud bang and some flashes...

author: kripton2035
author_rank: Super Contributor
timestamp: October 17, 2012, 03:09:01 pm
content: the go-esr meter has 2 1n4007 diodes in parallel with the capacitor to testso it seems a good protection for charged capacitors...can add a small power resistor may be to avoid the "bang" ?