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Are there any handheld DMMs that read ACV & DCV simultaneously?
Posted by
cvanc
on 22 Feb, 2018 21:40
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Does such a beast exist? It would be great for working on power supplies.
For me, extreme precision isn't needed; lower cost is the more desirable feature. Thanks for any suggestions you may have!
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#1 Reply
Posted by
Lightages
on 22 Feb, 2018 22:15
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I am not sure if you are asking for a meter that will display the AC and DC component of a measurement or if you want one meter to display AC input of a PS and also display the DC output at the same time.
If it is the former, then there are many meters that will do this but are generally not cheap, like not less than $100.
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#2 Reply
Posted by
alm
on 22 Feb, 2018 22:16
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Yes, there are. Many meters with dual display support this. For example high-end Fluke and Keysight handhelds (e.g. Fluke 189/289). I am not familiar with low cost (whatever that means to you) meters with dual display, but I imagine they exist.
This is useful to measure both the DC voltage and ripple at the same time. Keep in mind that update rate and input impedance may be reduced.
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#3 Reply
Posted by
0xdeadbeef
on 22 Feb, 2018 22:25
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The bigger Brymens like BM869s, BM829s and BM525s support dual display of AC voltage with DC offset. The cheapest one of them is the BM829s for around 150€.
Also the Gossen Mentrawatt Metrahit models with dual display (like Extra and Ultra but not the X-Tra and below) support this.
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#4 Reply
Posted by
cvanc
on 22 Feb, 2018 22:38
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This is useful to measure both the DC voltage and ripple at the same time.
That is exactly what I want to measure - DC output voltage and AC output ripple, simultaneously, through a single pair of test leads. I expect this would be a highly desired feature, but it seems to be available only at the more expensive end of the handheld DMM spectrum.
If I could find a $100 meter that did this, new or used, I would buy three of them today. (What the heck, make it $200.) But I can't find anything, which kind of surprises me?
In any case thanks for the input.
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#5 Reply
Posted by
Lightages
on 22 Feb, 2018 22:57
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#6 Reply
Posted by
soundtec
on 22 Feb, 2018 23:38
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My new UNi-t 171b measures AC+DC , and has dual display , worked out around 200 euros with tax and DHL fee's ,got it in from China via ebay.
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#7 Reply
Posted by
Lightages
on 22 Feb, 2018 23:52
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If there is a choice between a Uni-T and a Brymen close to the same price, then Brymen wins every time. I have both and know what I am talking about.
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#8 Reply
Posted by
soundtec
on 23 Feb, 2018 00:44
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Brymen 867 looks like good value for money alright ,comes in at around 170 euros from Germany ,DBu scale would have been usefull to me also ,something which is missing from the Uni-t . Im still happy with the 171b though ,more than good enough for my purposes.
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#9 Reply
Posted by
Synthtech
on 23 Feb, 2018 08:09
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I have both Keysight and Hioki handheld meters and both measure AC and DC simultaneously. I don’t think that any of the cheaper models from either of those brands do it though, you have to go for the higher spec’d models.
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#10 Reply
Posted by
joeqsmith
on 23 Feb, 2018 11:36
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If you just want basic AC+DC (square root of the sum of the squares) there are a few options. I've looked at a few low end meters that could display the separate AC and DC components as well.
https://youtu.be/fkf0V3Xvq_w?t=1168
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#11 Reply
Posted by
Jwalling
on 23 Feb, 2018 17:03
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#12 Reply
Posted by
hgjdwx
on 24 Feb, 2018 02:16
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you use the fluke45 DUAL DISPLAY test ACV 220V, fast,mid,slow, you will fand something,,,,,,
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Shop around for something that has a dual display for both AC and DC
That way you can see changes happening as you alter the circuit or view load effects etc
The Flukes are expensive
but maybe an affordable Brymen or a researched cheapie might be ok if you don't expect too much
A poor mans logging feature would be great too, probe now view later
Hey guys, if there is something like this around
cheap without frills, curves, eye candy and CAT freakouts, I'd be interested too
yes, even a humble Uni-T
urd
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#14 Reply
Posted by
nanofrog
on 24 Feb, 2018 02:53
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If you want a handheld, I'd second the recommendation for Brymen (
BM829,
BM867,
BM869).
If you would consider a bench meter, take a look at a
GW Instek 8251A.
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#15 Reply
Posted by
bitseeker
on 25 Feb, 2018 00:27
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In the US, you can also get Brymen meters under the Greenlee brand. I have the DM-820A and it works great for seeing AC ripple voltage while measuring DC output voltage.
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#16 Reply
Posted by
Vtile
on 25 Feb, 2018 00:32
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Technically speaking how it is done. It can not be done passively in any accurately manner and I'm skeptical that it can be done in actively neither considering the nonlinearities of the real life components. Damn... I did read the ACV & DCV somehow to current (amperes) and tension (volts). Yep, the AC + DC simultaneous measurement, with the one physical quantity is nothing special... Sorry for my misreading, I'm too used to see Vdc/Vac and not ACV&DCV.
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#17 Reply
Posted by
joeqsmith
on 25 Feb, 2018 01:48
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Technicallu speaking how it is done. It can not be done passively in any accurately manner and I'm skeptical that it can be done in actively neither considering the nonlinearities of the real life components.
You're skeptical that a handheld meter could simultaneously measure both the AC and DC components accurately? If you want to propose some sort of test, I could try and set it up with the meters I have to give you a demonstration.
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Technicallu speaking how it is done. It can not be done passively in any accurately manner
and I'm skeptical that it can be done in actively neither considering the nonlinearities of the real life components.
Agreed
on the other hand the OP and myself would probably be ok for an AC plus separate DC indicating cheapo meter to display anything grossly out or amiss, and not concerned with 100% accuracy
That said, if I had to 'trust' any meter at any price to do AC and DC properly, I would want to see what I'm testing on a scope first
and see how well the dual display meter actually does it's job, and what and where the limits kick in
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#19 Reply
Posted by
hgjdwx
on 25 Feb, 2018 10:28
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In the US, you can also get Brymen meters under the Greenlee brand. I have the DM-820A and it works great for seeing AC ripple voltage while measuring DC output voltage.
The V and mV of dm820a are separated, Therefore, In dual display mode, it may not be enough resolution to measure ripple with V range.
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#20 Reply
Posted by
BravoV
on 25 Feb, 2018 11:46
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Technicallu speaking how it is done. It can not be done passively in any accurately manner and I'm skeptical that it can be done in actively neither considering the nonlinearities of the real life components.
Made a discussion in this forum while ago (
Here), on DC voltage offset that appeared on mains line 220 Volt AC which ideally should be near zero volt.
Could you tell me whats wrong with this test ? Which part is not accurate ? I assumed you're not talking Metrology's class accuracy right ?
The big Fluke 287 on the left was measuring V-DC "
and" V-AC (at the smaller bottom display), while the right one Fluke 87 V was on the same mains line as 287, measuring the V-DC "only" to make sure both agree each others at the DC results.
https://youtu.be/WbyAR3qYrRMPhoto shoots of above test for better clarity. (click to enlarge the photos)
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#21 Reply
Posted by
evava
on 25 Feb, 2018 13:06
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I have the DM-820A and it works great for seeing AC ripple voltage while measuring DC output voltage.
No, you can not measure mV AC RMS ripple when on 50V range (common 10V-30V power supply).
Even if your meter is not overloaded big DC offset, AC RMS values are only defined FOR ABOUT > 5% of range, which in this example is about > 2.5V AC RMS.
Even 1% is only 500mV, and even on switch power supplies 30mV ripple you can not see and measure.
mVolt (AC RMS) readings have no value on 50V range!
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#22 Reply
Posted by
Vtile
on 25 Feb, 2018 13:24
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Damn... I did read the ACV & DCV somehow to current (amperes) and tension (volts). Yep, the AC + DC simultaneous measurement, with the one physical quantity is nothing special... Sorry for my misreading, I'm too used to see Vdc/Vac and not ACV&DCV.
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#23 Reply
Posted by
hgjdwx
on 25 Feb, 2018 13:49
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In the US, you can also get Brymen meters under the Greenlee brand. I have the DM-820A and it works great for seeing AC ripple voltage while measuring DC output voltage.
I have been looking for a long time, haven't a handheld multimeter can do this, In dual display mode, their ACV and DCV ranges are synchronized. including dual display desktop multimeter effect is not very good, like fluke45, In the aspects of speed that many dual display desktop multimeter is doing is not good.
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#24 Reply
Posted by
Lightages
on 25 Feb, 2018 18:28
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After all of this discussion, why is it necessary to measure both AC and DC on the same meter? If you only have one meter maybe but if you are working on electronics you want at least two meters anyway, three or four even better.
Connect the meters in parallel, set one on DC and the other on AC. Then you can see both components and with the added ability to adjust the AC range independently from the DC range so you can see smaller ripple. Make sure the meter being used has the better AC bandwidth and is TRMS.