Agilent U1733C vs. MESR-100 Mk2 vs. BM867 and AADE L/C Meter IIB - Page 1
Forum section: electronics / testgear

author: Mr Simpleton
author_rank: Unknown
timestamp: November 06, 2013, 10:17:52 pm
content: I decided to see how my Agilent U1733C, MESR-100 Mk2 and Brymen BM867 would handle a varity of electrolytic caps.The capacitors were at my bench after scrapping two switched ps, and the Siemens from a linear ps.U1733C was measuring caps with 100 Hz and ESR with 100 kHz to compare with MESR-100.With "rotten" caps the Agilent have problems to measure the capacitance, vs Bryment. But looking at the ESR, it really doesn't matterRounded up with a low capacitance test U1733C vs AADE L/C Meter IIB.I might look further in my junkbox and do some more tests later!1. Siemens 2200 uF 25 VU1733C 2419 uF (100Hz) ESR: 0.0631 ohm (100Hz) 0.0627 ohm (100kHz)MESR-100 0.046 ohm (100kHz)BM867 2587 uF2. Siemens 1000 uF 25 VU1733C 1158.2 uF (100Hz) ESR: 0.0684ohm (100kHz)MESR-100 0.069 ohm (100kHz)BM867 1245 uF3. No name 1200 uF 16 VU1733C 21.4 uF!! (100Hz) ESR: 7.2 ohm (100kHz)MESR-100 8.30 ohm (100kHz)BM867 2435 uF4. No name 1000 uF 10 VU1733C 80.8 uF!! (100Hz) ESR: 2.398 ohm (100kHz)MESR-100 2.35 ohm (100kHz)BM867 339.6 uF5 No name 47 /400VU1733C 42.58 uF (100Hz) ESR: 7.924 ohm (100kHz)MESR-100 9.57 ohm (100kHz)BM867 45.62 uF6 No name 22 /400VU1733C 14.256 uF (100Hz) ESR: 1.0491 ohm (100kHz)MESR-100 1.000 ohm (100kHz)BM867 14.97 uF7 No name 22 /25VU1733C 17.57 uF ESR: 6.8 ohm (100kHz)MESR-100 6.60 ohm (100kHz)BM867 22.32 uF8. Siemens 2200 uF 25 VU1733C 2411 uF (100Hz) ESR: 0.0500 ohm (100 Hz) 0.0530 ohm (100kHz)MESR-100 0.071 ohm (100kHz)BM867 2587 uF9 No name 68 pF /500V MicaU1733C 70.81 pFAADE L/C Meter IIB 70.22 pF

author: Lightages
author_rank: Unknown
timestamp: November 06, 2013, 10:46:26 pm
content: It is difficult to know which value is correct for any of these capacitors. As has been said a few time on this forum s that different meters might measure capacitors using different frequencies or even different methods. So what are your conclusions or ideas here?

author: Mr Simpleton
author_rank: Unknown
timestamp: November 06, 2013, 11:44:52 pm
content: My conclusion is that I trust the Agilent.... and will use the MESR-100 for in-circuit testing for bad caps. The MESR-100 is small and easy to use, and so far always found the bad caps (high ESR).Never really trusted a DMM for giving true values of caps or inductors though, and not sure the BM867 will change thisFor RF circuits I'll use the AADE as it tends to give good results on small values, pF and nH. But my gut feeling is that the U1733C is more accurate with-in its measuring range. Using my VNWA is really optimal when working on RF circuits and measure components at operational frequency.AADE and U1733C do compliment each other nicely.I do reserve the right to change my conclusion in the futureSee if I can run a test using my set of Boonton reference inductors...

author: Lightages
author_rank: Unknown
timestamp: November 06, 2013, 11:48:14 pm
content: I agree you that multimeters are not going to be as accurate as dedicated LCR meters. The U1733C should be the best reference. But in the field or if you don't have an LCR meter they are good enough.

author: Unknown
author_rank: Unknown
timestamp: November 06, 2013, 11:59:31 pm
content: In general meters that use dV/dt = I/C (DMMs) or resonance (which I believe is what the AADE meter uses) only work well with caps that are close to ideal, i.e. low D (ESR) and low leakage. This means that ceramic or film caps should work well, new electrolytics less so, and old electrolytics that might have a high ESR or high leakage will be way off. As is the case for the BM867 reading for the 1200 uF cap that is clearly dried up.

author: hgg
author_rank: Frequent Contributor
timestamp: November 07, 2013, 08:25:37 am
content: Did you average several measurements, or just one?

author: Mr Simpleton
author_rank: Unknown
timestamp: November 07, 2013, 08:47:59 am
content: Most measurements were repeated 2-3 times... not that I took the average, just checked that what I saw was consistent, i.e. low readings from U1733C measuring the high ESR caps etc.I'll see if I can do some more scientific measurement this weekend

author: mos6502
author_rank: Frequent Contributor
timestamp: November 07, 2013, 12:26:41 pm
content: First of all, with electrolytics, their "capacitance" (Xc) depends heavily on frequency (and also temperature). Since you didn't make all those measurements at the same frequency, they're pretty meaningless. Same thing with ceramics, BTW. The only somewhat meaningful measurement here is the mica cap.I'm pretty sure the MESR-100 doesn't do a vector impedance measurement, so there's no way for it to distinguish ESR from Xc. This is probably why it reads too high. It's really more of a guesstrument.The AADE uses the resonant method to determine Xc, so again, no vector measurements here, so ESR/DF can't be measured. The good news is it should be more accurate at determining Xc because ESR doesn't distort the measurement. Another good thing is that it actually uses the cap in an AC circuit. The big problem with the AADE (apart from the fact that it doesn't tell you very important parameters like DF and ESR) is you have no control over the measurement frequency. The printed value on a cap isonlyvalid at aspecific frequency, as given by the datasheet.Multimeters are pretty useless for doing capacitor measurements. Even a $500 Fluke or Agilent will just charge the cap and measure the time to reach a certain threshold. Essentially they're only testing the caps with DC, so they're not even measuring Xc, but rather ... something. That's why the Brymen gives you "accurate" readings even on defective caps that don't even work as caps anymore when subjected to AC voltage.Again, no info on the important parameters like ESR, DF or Xc.So, the only real measurement instrument here is the Agilent. You can forget the others because they either can't distinguish between Xc and ESR, can't yell you the DF, or you can't set the test frequency. They can be useful if you can't read the marking on a cap, but that's about it.If you want to know more, here's a PDF that explains just about everything about LCR measurements:http://literature.agilent.com/litweb/pdf/5950-3000.pdfI was actually going to buy the U1733C before I found out about the DE-5000. More accurate, no firmware bugs, real four wire measurements and only 1/3rd the price of the Agilent.I'd really love to see a shootout between these two.

author: zaoka
author_rank: Frequent Contributor
timestamp: November 07, 2013, 02:36:47 pm
content: QuoteI noticed that Agilent and Hioki DMMs are very good at detecting bad capacitors (high ESR) in a way that they show drastic change in measured value.For example I had 100uF 35V with high ESR, Fluke 87V measure 93uF while Agilent U1272A and Hioki 3801-50 are showing around 58uF.This is probably because these two are using DC method to measure capacity while Fluke uses AC.Also if Agilent U1272A can not determine capacity and is continuously trying to measure thats for sure that capacitor is bad while Fluke, since its using different way, will show some value.At the end I feel that we have to use only one meter to do the work and after a while we become familiar with it and know even more than digits are showing