ESR Meter- MESR-100 feedback- did i do something wrong ?

[herita]

Hi everybody,

Recently, i have bought one ESR meter (MESR-100) from the ebay .

link here :
http://cgi.ebay.fr/Capacitor-Capacit...item5ae7d1210c

But since my first try with one bad and good cap, the MESR-100 shows not so much difference betwen the good and the bad one. so i wish if there is someone can tell me if i did something wrong or the esr meter MESR is a brik can't be trusted ?

Here is the new esr meter MESR-100


I did Zero each time of test with each cap:


Bad cap: 6.3v 3300µf


With bad cap: - ok it shows : "-1.59 R" what means of "-" here ?
[Img]http://img59.*************/img59/2815/img2403resize.jpg[/img]

With good cap same value: 6.3v 3300µf : it shows "-1.70 R" not so much different with the bad one, i think



any suggestion, pls

[tom66]

Re: ESR Meter- MESR-100 feedback- did i do something wrong ?

Looks like it is faulty, somehow not storing the zero measurement correctly, did you use a shorting link for zeroing though?

[herita]

Re: ESR Meter- MESR-100 feedback- did i do something wrong ?

hi tom66, what did you mean use a shorting link for zeroing ?
uhm, sure, i did zero the device, and have shorted caps with screw device already.

[tom66]

Re: ESR Meter- MESR-100 feedback- did i do something wrong ?

To zero it, you may have to connect the plus and minus of the TESTER together, so it can measure any resistance of its contacts and eliminate them from the test.

[herita]

Re: ESR Meter- MESR-100 feedback- did i do something wrong ?

ok, nice, but i think that i have done it already, because the MESR-100 has its own bouton Zero to zeroing, so before testing each cap, i did zero it down.

[mariushm]

Re: ESR Meter- MESR-100 feedback- did i do something wrong ?

You may have to connect the two probes together or use a wire to make the connection between the terminals BEFORE you press the zeroing button.

The meter will have an internal resistance without the probes, when you put the probes in the sockets the resistance of the cables and the tips adds up and changes the measurements, so you have to zero it again.
That's done by touching the probes (so shorting the circuit).

If it still shows bad values, there should be some potentiometers on the back that can be used to adjust what you see.

[herita]

Re: ESR Meter- MESR-100 feedback- did i do something wrong ?

humh, ok, so after you, there will be steps which i have to follow :

1. with the probes already put in the meter, i connect them together and switch on the meter.
2. alway with the two probes connect together, i press zero to zeroing the meter.
3. after zeroing, i pull out the two probes and begin to test the cap.

haha, i did the 3 steps above and after pulling out the two probes my meter says overflow.

[tom66]

Re: ESR Meter- MESR-100 feedback- did i do something wrong ?

That is fine, now test with a cap and see if it still says overflow.

[severach]

Re: ESR Meter- MESR-100 feedback- did i do something wrong ?

Lead zero doesn't sound like the problem. Leads typically measure 0.10 ohms or less, not 1.5 ohms. I find it easier to subtract the value in my head rather than zeroing all the time. Meters often are not designed to notify you that the zero adjusted resistance is less than zero meaning the zeroing wasn't done accurately. Maybe that's what this meter is doing, indicated by the negative (-) value.

After zeroing, make sure that shorting the leads reads zero. Press the leads together hard and soft to see if varying pressure changes the zero value. Find some low ohm resistors to see if the meter shows the same resistance as marked.

While I agree that your blue cap (OST?) is bad I do not agree that your "good" Ltec cap is good. Can you try some known low ESR caps from Nichicon, Sanyo, or Panasonic that we can have a little more trust in?

Call me crazy but I trust a cheap meter before I trust a cheap cap.

I like the probe holes. The MESR-100 isn't cheaper enough than the Atlas ESR70 to be worth losing the microfarad measurement.

[herita]

Re: ESR Meter- MESR-100 feedback- did i do something wrong ?

hi everybody,

i think that everything is fine now, i did these steps before mesuring caps and the meter can finally tell me wich cap is good or bad.

Severach, i definitely agree with you, cheap cap can't be trusted. ok the green cap Ltec is a band new cap (i have got about 200pieces of these), but i have tested also with some others brand like Nichicon.

and with the MESR-100, these probe holes are ok, but i also have to use a tweezer in order to zeroing the meter before using.

i will try to make a video when i use this meter, in order to help others guys like me in the future

and yes, the Atlas ESR70 is expensive and you have to prepare battery for it, i think.

[int0x13]

Re: ESR Meter- MESR-100 feedback- did i do something wrong ?

hi everybody,

i think that everything is fine now, i did these steps before mesuring caps and the meter can finally tell me wich cap is good or bad.

Severach, i definitely agree with you, cheap cap can't be trusted. ok the green cap Ltec is a band new cap (i have got about 200pieces of these), but i have tested also with some others brand like Nichicon.

and with the MESR-100, these probe holes are ok, but i also have to use a tweezer in order to zeroing the meter before using.

i will try to make a video when i use this meter, in order to help others guys like me in the future

and yes, the Atlas ESR70 is expensive and you have to prepare battery for it, i think.

Hello herita, i wanted to buy the same model on ebay, finally do you advice it or not?
Did you do the video to show how to use the meter?
Thanks

[MDOC]

Re: ESR Meter- MESR-100 feedback- did i do something wrong ?

herita,
Do a little test to find out if you really need to zero the meter when using the terminal block (the holes) in the meter:
1) Zero the meter by attaching the two probes together.
2) Remove the probes from the meter. Insert a known good cap in the terminal block. Write down the reading.
3) Without removing the cap, turn off the meter. Turn it back on again 5 seconds later.
4) Without zeroing again, measure the cap again. Note the meter reading.

If there is no appreciable difference in the reading, you don't need to do zeroing because you're not using the probe leads.