Multimeter resistance question

[Bored2Tears]

First, I hope this is an OK place for this thread. I have no idea why, but I am unable to post in the New members forum, which is where I originally intended to put this. I seem to be able to post in any other forum but there. So, anyone have ideas on that?


I bought a cheap Digital Multimeter at Harbor Freight. (I know, buy cheap...get cheap results). My thought process was that I could use a digital multimeter anyway, and it would be a good "double check" of ohm resistance if I ever step up to a regulated mod that has the resistance tester on it. I plan to do some coil building soon. So, I wanted the baseline resistance and touched the lead tips together and it was all over the place. I tried it a dozen times, and was very careful to hold them steady. It finally settled on 1.2 ohms. Is that crazy? I thought the typical baseline resistance of the leads was usually in the .02 to .05 ohms range.

I think the thing is just junk and should be returned...which I am going to do. But, do I need to spend $30 to get a decent one that will be accurate on resistance testing, or have others been using cheap multimeters with good results? Am I just unlucky?

Thanks.

 

[Bored2Tears]

Want to add that my main reason for owning a multimeter was to start the coil building. If it's gonna cost me $30 to get a decent one that will measure resistance accurately....then I will forego buying the multimeter and just buy an MVP 2.0 or istick with that function on it. I am not sub ohming, so relative accuracty for 1.8ohm coils or higher is all I really want.

 

[Topwater Elvis]

Ohm inaccuracy variance using cheap meters is quite high, if you bought several you should end up with one that would read within .2 of accurate.
Spend a little more the range is .2 ~ .015.
Take it back for refund or exchange.

The MVP or istuck will be accurate enough for 1 ~ 3 ohm range / if you have no plans for sub ohm builds.

 

[Bored2Tears]

Ohm inaccuracy variance using cheap meters is quite high, if you bought several you should end up with one that would read within .2 of accurate.
Spend a little more the range is .2 ~ .015.
Take it back for refund or exchange.

The MVP or istuck will be accurate enough for 1 ~ 3 ohm range / if you have no plans for sub ohm builds.

Yeah, I would still like to have a digital multimeter for other purposes....so I am gonna exchange this one and see if I got a dud. Guess for $6 I can exchange it once or twice to see if I can get a winner in the bunch.

Wondered anyone else out there has had to return a few of these for that reason? I guess I could have tried putting in a fresh battery...but all the other functions were working ok, and it seemed to test the voltage output of the battery fine....it just had too much resistance in the test leads for me to want to use it on testing coils.

Could that have been off because the battery installed in it was low/dying out?

 

[Equilibrium]

I agree... You should be able to get a DMM for $30 that will suit your needs. My meter has an internal resistance of .1 ohm, so when I build a coil that reads .8 ohm, it's actually .7 ohm.

 

[tj99959]

$30, are you kidding?

Fluke 1587 Insulation Multimeter - Fluke Corporation

And don't forget the NIST calibration $145 add on

 

[Bored2Tears]

So is .2 ohms about how accurate the built-into regulated devices are? They are close to as accurate as a decent multimeter? They are certainly a lot more convenient to use on an atty than the multimeter... just pop it on and check it out before firing it.

 

[Bored2Tears]

$30, are you kidding?

Fluke 1587 Insulation Multimeter - Fluke Corporation

Uhm... I probably wasn't clear. I have no interest in spending $750 on a multimeter...or $75, or even $30. I'm trying to determine if it is possible to get a cheap digital multimeter with relative accuracy for resistance. If I can't get one for under $30, then like I said.....I will just get an MVP 2.0 or istick with that function on the device.

So the question is : do most people who own cheap (say $6) multimeters get better accuracy than what I got on the one I bought. I don't think I can trust anything with an internal resistance of 1.2 ohms reading if I am trying to check in the range of 1.0 to 3.0 ohms.

 

[Topwater Elvis]

Sure it is possible to get a reasonably accurate cheap dvom, you may have to exchange two or three or a dozen or so.

If you have no plans to build sub ohm coils the ohms checker on most regulated devices is accurate enough.

 

[TyPie]

Just a thought. A multimeter is a great tool to have around the house and car that will pay for itself many times over. It really pays to have a good one and learn how to use it. The better ones are more accurate and safer. There are tons of tutorials on youtube for testing ecig equipment as well as all things electrical. I have both analog and digital models.

For testing ecig equipment, it is generally not dangerous. As always though, be very careful that you know what you are doing around higher voltages, household electricity, etc. Electricity can kill you. For higher voltages and amps, the thought of using a cheapie multitester scares me to no end.

 

[inswva]

I had this one long before I started vaping:

Amazon.com: INNOVA 3320 Auto-Ranging Digital Multimeter: Automotive

It consistently (like every single time) shows .1Ω of resistance between the leads. I don't build below .3Ω so, with the batteries I'm using in my mech mod, I'm all good. I usually "double check" on my DNA30 box. The box and DMM are almost always right on the money. If there is any variance, the box usually reads .1 higher.

For $20, I consider it a pretty good DMM.

 

[xwarp]

1st, the Fluke meter recommended above is NOT a meter I'd recommend for anyone that has no experience in the electronic field.

2nd, when measuring values such as those that are in the milli, micro, nano, pico ranges, it usually requires equipment that is somewhat designed for that specific purpose since at those ranges, those values are often affected by ambient temperature and types of metals making connections.

3rd, being an electronics tech of 28 years, I will tell you that accuracy and stability costs money and harbor freight meters aren't going to cut it for this purpose in my opinion.

The most accurate way to measure resistance values of 1 ohm or below is using the 4 wire measurement, but that is specialized equipment.

Note that when you are talking the difference of .5 ohms with a 3.7 vdc supply, with .1 ohm, you are at 37 amps and .05 would be 74 amps, I certainly wouldn't put my faith in a 3 dollar meter in building something that has the potential to literally blow up in my pocket or in my face.

 

[Kaezziel]

I would also suggest, for your purpose, one of the little box ohm readers with the 510 connections. They are perfectly fine for the builds that you are planning. Those can be found for around $15... fasttech may have them cheaper...

510 Ohm Reader @ Giantvapes

 

[Kaezziel]

1st, the Fluke meter recommended above is NOT a meter I'd recommend for anyone that has no experience in the electronic field.

2nd, when measuring values such as those that are in the milli, micro, nano, pico ranges, it usually requires equipment that is somewhat designed for that specific purpose since at those ranges, those values are often affected by ambient temperature and types of metals making connections.

3rd, being an electronics tech of 28 years, I will tell you that accuracy and stability costs money and harbor freight meters aren't going to cut it for this purpose in my opinion.

The most accurate way to measure resistance values of 1 ohm or below is using the 4 wire measurement, but that is specialized equipment.

Note that when you are talking the difference of .5 ohms with a 3.7 vdc supply, with .1 ohm, you are at 37 amps and .05 would be 74 amps, I certainly wouldn't put my faith in a 3 dollar meter in building something that has the potential to literally blow up in my pocket or in my face.

I agree with all of this!
I use a Vici 4-wire milli-ohm meter for testing my builds, but I am an electronics tech as well. I typically build low enough that I don't trust even the $15 milli-ohm boxes... but I don't trust a lot of things/people/animals/plants/air/water......

 

[tj99959]

There was a bit of sarcasm involved with posting a $700 Fluke, there really are cheaper models of the Fluke to choose from.
I posted that tho' just to show that like most everything else you get what you pay for.
I would also point out that there is more involved in making a meter accurate than just the resistance in the leads, and the lower we go with the resistances we use the more inaccurate cheap meters become.

 

[Kaezziel]

LOL... I caught the sarcasm, TJ.... no worries on my end!
I thought about posting a $5K micro-ohm meter....

I absolutely agree with your last sentence, too.... that's why I don't own one of the $15 box ohm readers.... don't trust them in deep sub-ohm territory any more than I'd trust a Hi-Point 9mm in a gun fight...

 

[xwarp]

LOL... I caught the sarcasm, TJ.... no worries on my end!
I thought about posting a $5K micro-ohm meter....

I absolutely agree with your last sentence, too.... that's why I don't own one of the $15 box ohm readers.... don't trust them in deep sub-ohm territory any more than I'd trust a Hi-Point 9mm in a gun fight...

I'm fairly new to the e-cig world and anything electronic gets my attention, but I doubt that I'll get into wrapping coils and what not.

I don't think I'd trust a Hi-Point either.....I'll stick with either my S&W 645 or 5906........

 

[Kaezziel]

I'm fairly new to the e-cig world and anything electronic gets my attention, but I doubt that I'll get into wrapping coils and what not.

I don't think I'd trust a Hi-Point either.....I'll stick with either my S&W 645 or 5906........

I went a long time on pre-built coils, myself... now I'm spoiled, because I found that even my crappiest coil is 1000X better than any one that I ever bought... LOL
Colt 1911... .45 ACP for me... I accept no substitute!!
My boss at work bought a Hi-Point, against my suggestions otherwise... he does nothing but whine and complain about that thing.....

 

[xwarp]

Want a good meter.....look at these....lol

 

[Susan~S]

First, I hope this is an OK place for this thread. I have no idea why, but I am unable to post in the New members forum, which is where I originally intended to put this. I seem to be able to post in any other forum but there. So, anyone have ideas on that?

Once you get past 75 posts you are no longer allowed to start threads in the New Member section. However, you are allowed to respond to threads started by other new members.