# Multi meter question?

#### Terry01

Jul 5, 2017
206
I have a Hyelec MS89 multi meter I bought a while back,just a Chinese cheaply! 30 or 40 quid or there abouts. I've used it for odd jobs for a couple of years.
I got a Extech Ex505 multi meter and a Tenma 30V 5A PSU recently when I decided to get into hobby electronics. The Extech i got from eBay 2nd hand still boxed and looks as new,the Tenma I got new from Farnell.

Today I tested both meters taking readings simultaneously from my Tenma both under load and not.
The results have left me a bit puzzled.
The Hyelec display matched the PSU display spot on apart from 2 measurements and those were like 6.38V on the PSU and the meter read 6.37V and another one similar to that. I literally took 100s just changing the PSU Volts and watching the cheapo meter shadow it almost flawlessly.
When I stuck the Extech on it was reading a bit out. Like 5V don't the PSU and 4.87V on the meter,3.7V on the PSU and 3.48V on the meter. Just at rest the meter in DC mode measuring MV jumps around a bit.
The Extech is the more expensive by quite a bit but I'm wondering if its toast,maybe took a knock or something.
Anyone any thoughts on this?

#### kellys_eye

Jun 25, 2010
4,852
Bouncing mV is quite common - what does it read with the leads shorted?

Have you checked the Hylec against any other reliable power supply, just to be sure the Tenma is ok?

If the PSU is outputting what it's meant to be then the error is rather high on the Extech so as someone once said - "Don't just stare at it...... take it apaaaaart".

Common faults with test meters include poor connections between probe socket and pcb (internally). It could just be a calibration issue so you'd have to take it apart to fix anyway.

Post some internal pics of the meter.

#### (*steve*)

##### ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
25,505
Try replacing the batteries first.

#### (*steve*)

##### ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
25,505
Oh, and the quote is "don't turn it on, take it apart"

#### kellys_eye

Jun 25, 2010
4,852
Oh, and the quote is "don't turn it on, take it apart"
Yeah - that's the quote.

Being as old as I am my hearing doesn't encompass high frequencies very well these days so I tend to miss the exact nuances of Dave's utterings.....

#### Terry01

Jul 5, 2017
206
When I short the leads it returns to zero. I put a new battery in soon as I got it.
There's a club not too far from me I've just found out about that has all the test stuff. Its like a hacker club. I'm sure they will have a decent meter I can use to find which one of mine is correct. I NEED A FLUKE! Ha ha.
Thanks for the help I'll let you know how I go. As much as I don't want it to be my Extech,I think it will be the one that's out.
I've just decided.....I'm going to treat myself to a nice new Fluke at the end of the month (payday)!
What's the best one for hobby electronics around the £100 mark?

Last edited:

#### (*steve*)

##### ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
25,505
I NEED A FLUKE!

You need just one meter. That way you know it's correct. Once you have 2 or more you're never sure

I have a series of high tolerance resistors (mostly 0.01% or better) that I use for checking resistance ranges, and a very accurate 10V reference (it was initially calibrated as being 7.5uV high) that I use to check voltage ranges.

These days I generally check one meter against another. I have ummm... several. No Flukes, but HP, and a couple of Tektronix. The good brand name devices are solid.

Extech... I would check out teardowns and then not buy one.

If you're going to get a Fluke, don't get the cheaper ones made "for the Asian market", they are not well protected (and neither are you).

#### Terry01

Jul 5, 2017
206
The continuity has now stopped working on the Excrement Tech now too! Pile of chit! Gonna treat myself to a new meter this weekend then take the Excrement Tech apart and strip it! Few bucks down the swany but you live and learn. Wish I new enough to try and fix it just for fun and practice.

Jan 5, 2010
7,682
I have two inexpensive but not cheap ($30 -$50) meters. They agree to ± last digit. And I have had not trouble with either of them. I can't see $100s for a meter. Bob #### Terry01 Jul 5, 2017 206 Funnily enough the other meter I have i paid £30-£40 for a couple years ago works fine....I think! The only thing I have to compare it to is my bench PSU. They match almost exact when compared at different volts so I tend to think they are correct unless they are out by exactly the same amount which I doubt. The PSU I bought from Farnell so its not a knock off from ebay so prob near enough. The Extech I bought from eBay! I've seen a nice Fluke 87 at a decent price so I'll get that at the weekend I think. #### kellys_eye Jun 25, 2010 4,852 If all you're using a meter for is bench work then any cheap meter with suitable accuracy will do. There is a lot of internet discussion and enthusiasm for the ANENG AN8008 ($25 or under) as it reads to an accuracy of μV, has a 10,000 count display and is pretty well supplied with all the probes and clips you need.

If, however, you are going to use a meter for AC mains work then CATII/CATIII classification is essential and the cheap meters, whilst LABELLED as such often fall well short when it comes to looking inside and checking the protection actually fitted! Beware!

I use three/four meters - a couple of cheap UNI-T's for bench work and two models of professional clamp meter for mains/high AC/DC current work. After seeing the ANENG meters being demonstrated I'm keen to purchase FOUR to fit into my test bench as permanent displays.

#### Terry01

Jul 5, 2017
206
Yes I've seen a couple of reviews (videos) of the ANENG and they are impressive for the price. I did think about one and may still get one.
Out of the two meters I have now the £30-40 Hyelec copy of something or other is the one I trust the most. I want 1 meter I can trust as much as you can trust a meter. I like the Fluke87 and the price is right so I'll get one to keep me happy.
I will use it mostly for bench work but it means if I ever do need one for mains AC or whatever I have it there. I'm still at the stage too where most things electronic are new to me so who knows what direction I'll take or when.
There's a club up near where I stay so I'm going to drop in there and see what i can learn.

#### kellys_eye

Jun 25, 2010
4,852
For the amateur experimenter a multimeter with as many functions as possible helps keep clutter on the workbench down to a minimum AND costs lots less than individual purpose-built test equipment.
Some of the multimeters out there do the basic Volts/Amp/Ohms and capacitance, temperature, frequency, diode/semi conductors, etc etc but I'd never consider using them for mains or high current purposes.
When it comes to high volts/amps all you need is a very basic but 'pro' model meter without all the fancy doo-hickies - and these can also be 'cheap' to purchase simply because they have restricted functionality.
After-market meters can be a good buy if you are inclined to do tests that require 'laboratory accuracy' - and after 40 years in the business I've yet to encounter such an occasion! - but they tend to be more trouble than they're worth. Avoid.

So - get two. A basic multi-function device and chain it to your workbench and a 'pro' (but basic) meter for heavy duty use.

Of course, after a multimeter, you should look to obtain an oscilloscope and when you get to this stage you really can't spend enough on one! That would be a lengthy thread indeed.....

#### Doug3004

Sep 5, 2014
119
You can buy a Fluke (or other high-end meter) if you want, but the accuracy and safety improvements aren't likely to be significant to a hobbyist who only works with wall-socket voltages and lower.

I have a few cheap multimeters and no expensive ones. All the cheap ones agree with test module values within 1% or so. That is less error than most analog components have, it's tough to argue that you need anything better. Some bigger motor caps come with 20% tolerances when new....
Besides--
The last time I looked, the cheapest Fluke meter that had what I would consider to be "complete" features cost around $350. One could buy that. Or, one could spend$30 for an entirely usable Chinese meter, spend another $20 for a backup/second-opinion meter, and still have a LOT of money left over to spend on project parts and supplies. Oddly enough--one of the most common causes of multimeter accidents is having the leads plugged into the wrong jacks as you turn the selector switch. The best meters have jack shutters that prevent you from doing this entirely. Flukes don't have jack shutters. Flukes will beep at you, but that doesn't stop you from making the error (and by the time you hear that beep it might be too late to save your$350 meter,,, ). One cheap meter that does have jack shutters is the HoldPeak HP-890, for around $25. ~~~~~~~~~ Also we note: the ANENG AN8008 appears to be a UNI-T model. Many cheaper multimeters are made by only a handful of Chinese companies; two of the biggest China DMM companies are Sinometer and All-Sun. Last time I counted, Sinometer showed about 175 DMM models and All-Sun listed about 120. http://www.sinometer.com/ http://www.all-sun.com/ If you bought a cheap meter from anywhere, there's a pretty good chance that one of these two companies made it, or makes an identical model. You can't buy from their websites as they are OEM manufacturers, but you can often track down meters by their model numbers. Sinometer sells many of their meters under their own name, but they own other names also and sell the same meters under them too (tho not all are available in all countries). All-Sun sells very few of their meters under their own name. #### (*steve*) ##### ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator Jan 21, 2010 25,505 Flukes don't have jack shutters. Flukes will beep at you, but that doesn't stop you from making the error (and by the time you hear that beep it might be too late to save your$350 meter,,, ).

Other than blowing a fuse, you'd be surprised what you can do to a good meter without destroying it.

Try measuring the mains on the resistance range for example. Don't try it on a cheap meter.

#### Doug3004

Sep 5, 2014
119
Other than blowing a fuse, you'd be surprised what you can do to a good meter without destroying it.

Try measuring the mains on the resistance range for example. Don't try it on a cheap meter.
Why? You're not supposed to do that.

When a lot of places do multimeter reviews, the accuracy of even the cheapest meters is so good that they have to resort to intentional misuse to show how a "better" meter is better--and it looks rather, , , , contrived. It's kind of like testing a \$25,000 oscilloscope by throwing it down a flight of stairs, and then complaining that "it's cheap because it broke". It's not really a meaningful demonstration of anything.

#### (*steve*)

##### ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
25,505
Why? You're not supposed to do that.

Because accidents happen. The post of your I was quoting was you criticising fluke meters for their lack of shutters.

All shutters do is make it harder to have the probes connected to the wrong jacks. They do nothing to stop you using the meter incorrectly.

If you're using a meter in a high energy environment, the last thing you want is your meter exploding. Preferably the meter will survive.

Even in a lower energy environment it is a good thing that you can be confident that accidentally having the meter in the wrong mode, or placing the probes in the wrong place won't result in you having to buy a new meter.

If you need or value that protection, then why argue against it? If you want to save some money and it's not going to affect your safety, fine.

#### BobK

Jan 5, 2010
7,682
As someone who keeps extra fuses for my meters in stock, I can testify that mistakes are made!

Bob

#### kellys_eye

Jun 25, 2010
4,852
I've only ever witnessed a multi-meter fuse 'event' - never caused or been the victim of one!

The shipyard chief electrician was chasing down a fault in a distribution unit on the wheelhouse of a new vessel we were commissioning - in front of the vessels prospective owner and all the shipyard 'big wigs'.

There was an ENORMOUS 'BANG!!!' from the direction of the chief electrician and a very prolonged silence followed by my voice piping up from under the console I was working on at the other side of the wheelhouse......"what the F*** was that!"

Chiefie had put a meter set to amps across a 440V line.....

Scared the living daylights out of everyone.

I was expecting Chiefie to turn around looking like a blackened daisy (like Tom & Jerry used to manage) but all he did was grimace at me......

#### (*steve*)

##### ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
25,505
This is an interesting article.

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