ESR meter - Page 1
Forum section: electronics / testgear

author: Charlie86
author_rank: Regular Contributor
timestamp: September 12, 2018, 09:07:45 pm
content: Hi,which ESR meter do you suggest for measuring capacitors in circuit. Main reason for buying this device is that I don't need to desolder all caps to find bad ones.Some of these devices also have LCR meter which is nice, but I am not sure how accurate this devices are.Like I said main usage will be finding bad caps, without desoldering them from PCB.I find few of them, which one is the best?https://www.aliexpress.com/item/BSIDE-ESR02-PRO-Digital-Transistor-SMD-Components-Tester-Diode-Triode-Capacitance-Inductance-Multimeter-ESR-Meter/32832292103.html?spm=2114.search0104.3.16.669e5530auZJY6&ws_ab_test=searchweb0_0,searchweb201602_2_10065_10068_10059_5016815_5016715_10696_100031_10084_5016615_10083_10103_451_10618_452_5016915_10307_10820_10301_10821_10303-normal#cfs,searchweb201603_16,ppcSwitch_5&algo_expid=c470eeb8-4937-47f5-8a84-aab8b15af4f3-5&algo_pvid=c470eeb8-4937-47f5-8a84-aab8b15af4f3&priceBeautifyAB=0https://www.aliexpress.com/item/Professional-Resistance-Capacitor-Circuit-Tester-High-Precision-Measuring-Capacitance-MESR-100-ESR-Capacitance-Meter/32539087910.html?spm=2114.search0104.3.59.669e5530auZJY6&ws_ab_test=searchweb0_0,searchweb201602_2_10065_10068_10059_5016815_5016715_10696_100031_10084_5016615_10083_10103_451_10618_452_5016915_10307_10820_10301_10821_10303,searchweb201603_16,ppcSwitch_5&algo_expid=c470eeb8-4937-47f5-8a84-aab8b15af4f3-10&algo_pvid=c470eeb8-4937-47f5-8a84-aab8b15af4f3&priceBeautifyAB=0https://www.aliexpress.com/item/2IN1-100vA-to-50mA-Constant-Current-ESR-CAPACOTANCE-METER-MEC100-V1-Auto-ranging-Capacitor-ESR-Low/32617802157.html?spm=2114.search0104.3.75.536b42feaqylkI&s=p&ws_ab_test=searchweb0_0,searchweb201602_2_10065_10068_10059_5016815_5016715_10696_100031_10084_5016615_10083_10103_451_10618_452_5016915_10307_10820_10301_10821_10303,searchweb201603_16,ppcSwitch_5&algo_expid=fe9d5162-ba9b-4a40-8875-cf158ba3823b-13&algo_pvid=fe9d5162-ba9b-4a40-8875-cf158ba3823b&priceBeautifyAB=0https://www.aliexpress.com/item/New-Arrival-M328-Digital-Component-Transistor-Tester-Diode-Triod-Capacitance-ESR-Meter-12864-High-Quality/32737018042.html?spm=2114.search0104.3.178.536b42feaqylkI&ws_ab_test=searchweb0_0,searchweb201602_2_10065_10068_10059_5016815_5016715_10696_100031_10084_5016615_10083_10103_451_10618_452_5016915_10307_10820_10301_10821_10303,searchweb201603_16,ppcSwitch_5&algo_expid=fe9d5162-ba9b-4a40-8875-cf158ba3823b-28&algo_pvid=fe9d5162-ba9b-4a40-8875-cf158ba3823b&priceBeautifyAB=0https://www.aliexpress.com/item/ZT-X-Digital-Auto-Range-Analog-Multimeter-Transistor-Battery-Tester-esr-Meter-Voltmeter-True-RMS-AC/32897108121.html?spm=2114.search0104.3.95.669e5530auZJY6&ws_ab_test=searchweb0_0,searchweb201602_2_10065_10068_10059_5016815_5016715_10696_100031_10084_5016615_10083_10103_451_10618_452_5016915_10307_10820_10301_10821_10303,searchweb201603_16,ppcSwitch_5&algo_expid=c470eeb8-4937-47f5-8a84-aab8b15af4f3-15&algo_pvid=c470eeb8-4937-47f5-8a84-aab8b15af4f3&priceBeautifyAB=0Thank you

author: coromonadalix
author_rank: Super Contributor
timestamp: September 12, 2018, 10:18:04 pm
content: Some of them are the same variants .... go for an de-5000 instead, it will give you more for your money.The De-5000 has some eevblog thread here and user feedbacks ..

author: bitseeker
author_rank: Super Contributor
timestamp: September 13, 2018, 01:42:13 am
content: Charlie, no ESR or LCR meter will be able to tell you which caps are bad, in circuit, under all circumstances. In many (most?) cases, you can only know for sure after desoldering and isolating at least one side of the component being measured. Unless you know the behavior of the circuit in which the capacitor resides, you can easily be misled as to whether there even is a bad capacitor.For example, a very common ESR-related case is with electrolytic capacitors used to filter noise on power rails. Since it is such a common issue, you decide to take a measurement in circuit to see if they might need to be changed. The ESR value does seem high. Then, you notice that there are four capacitors. Are they all on this rail? Looking under the board, yes they seem to be in parallel with one another. So, which one has the high ESR? Is it just one of them? Maybe two? Maybe all of them? Maybe none of them because there appears to be a bleeder resistor on the rail. Wait, what effect does this transistor have when the meter is connected?I second the recommendation on the DE-5000 for all-around LCR/ESR use. If you don't need to measure ESR often and don't need selectable frequency LCR functionality, the $15 transistor/ESR tester is fine (a.k.a., M328, AY-AT, etc.).

author: Charlie86
author_rank: Regular Contributor
timestamp: September 13, 2018, 10:42:49 am
content: Wow thank you.I see I have big lack of knowledge about this meters.Basically there is no device which is capable of detecting bad caps in circuit.Thank you one more time.

author: PA0PBZ
author_rank: Super Contributor
timestamp: September 13, 2018, 12:08:42 pm
content: Quote from: bitseeker on September 13, 2018, 01:42:13 amSince they are all parallel you will not notice a high ESR until they all have a high ESR, and the same goes for the bleeder resistor. Anything parallel can't increase the resistance of the whole. Of course if you have 4 x 1 Ohm (ESR) and one goes bad the ESR will increase from 0.25 Ohm to something a bit higher but never higher than 0.33 Ohm. And since the better ESR meters use a voltage below the diode threshold a transistor should no be a problem.

author: bitseeker
author_rank: Super Contributor
timestamp: September 14, 2018, 12:37:25 am
content: Precisely. An ESR meter isn't going to explain any of these things when it shows an in-circuit reading.

author: Gyro
author_rank: Super Contributor
timestamp: September 14, 2018, 09:59:18 am
content: The MESR-100 has very good resolution (around 0.005R so useable even on very low ESR caps (it has approximate sine waveform) and will measure AC impedances at 100kHz generally. It measures ESR only though, no capacitance measurement. The same manufacturer offers a separate capacitance meter.The MEC-100 that you linked is a 'new kid on the block', obviously from the same manufacturer and appears to combine ESR and Capacitance measurement in the same in instrument. I don't have any experience of it though.