Multimeter Voltage Accuracy - AD584 Voltage Reference - 12v Solar Shed
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- Опубліковано 19 бер 2016
- I use my multimeters a lot. I use them to determine whether a device over charges my lithium ion cells and my Arduino projects are reading accurately for example. But how do I know that my meters are correct? And it begs the question whether all meters can be relied upon in this day and age.
In this video I test my meters against an AD584 precision voltage reference module which I bought from Ebay: goo.gl/30alpf
❗️These links are affiliated and I may earn a small commission if you purchase❗️
Great video. I have been pondering this for a while. Thanks for the answer. I enjoyed your explanation and comparisons. Cheers buddy I will have to get me one of those.
Consider also that putting many voltmeters together in parallel like you have done will affect the input impedance of the circuit. 4 meters together will reduce the impedance down to 25% of a single meter, so a 10k ohm per volt will be 2.5k ohm per volt which can load the supply/test voltage. Not as big an issue with higher impedance digital meters as it would be for an older analog movement but worth a thought. Karl
Useful info. Thanks very much.
Enjoyed the video. Liked and subscribed.
What a handy device, i may well well avail myself of one.
Great video !
Brilliant Video Adam thanks for the info...im on the market for a new voltmeter and this will help.
The DT-830 meters (and similar) have a calibration pot on the board. I have several in Cen-Tech garb (Harbor Freight's line) - most of those were "free with coupon". Once calibrated to the AD584, they're usable for much of the testing I do, such as: Is a vehicle battery charged? Does a solar panel have output? Is an AC outlet (or sine wave inverter) near its expected voltage?
You might want something better for checking the output of a balance charger for a string of lithium batteries.
+notyoung Thanks. Actually I opened up that cheap meter and found that where a pot could be fitted they'd soldered a fixed resistor! I guess I could buy a pot and pop it in myself though. Thanks for your comments.
A person with one clock always knows the correct time. With two you are never sure.
"Thank You", thank you very much 😎
That's really useful - we were just doing some work and realised that two meters showed different readings - and it occurred to me I had no way to know which, if either was correct. I'll have one of these - thanks...
Pete.
Wow - that cheap meter is MILES out.
+Peter Scargill Yeah, you don’t have to spend too much more though to get a pretty accurate reading.
Well, what I have done this afternoon is to buy the very same accurate voltage reference depicted in the video - so that at least I can put a correction factor on a little sticky note on my meters....
I managed to pick up an HP 3455A for £100, and thanks to a voltage ref and a couple of precision resistors, I'm confident that it is more accurate than a GW Instek GDM8341 in recent factory cal. Without the accurate Vref I would have assumed it was the HP that was out (last cal in '09), they are very handy things to have to hand.
Hi Adam, thank you for this,it was very helpful for this neophyte.
I know it is over 5 years since you posted this but wondered what budget voltage reference devices you might recommend today.
If I could impose further, what other gadgets could you suggest for testing other settings on a typical multimeter?
Thanks.
Keep them coming, I love these video's.
Mike bkk
+Bangkok Homes thanks again
Those cheap multimeters are handy things to have lying around in other places where you might want to grab something for a quick check. Especially in environments where you might not want to keep a good meter. If you look inside it up by the display end of the board you might be lucky enough to have a calibration pot. Now you can use your new voltage reference unit to improve it. :)
+xanataph Very true, they have their uses. I'm not one of these people who thinks that you've got to spend hundreds (or even tens) of pounds on a meter for the low voltage DC stuff I'm doing though! I've not opened the cheapo meter up yet, might be for another video. :-)
+xanataph No trim pot sadly. I'll find a use find a use for it though!
+Adam Welch That's a pity. All those cheap ones I have opened have them, but I guess when you're going for super-low price a pot as a component looks rather dear. Maybe there's still a pad for it where they have just strapped in a fixed resistor to cut costs?
+xanataph You know your stuff sir. That's exactly what they've done! I might search around for a suitable pot at some point.
I keep one of the harbor freight meters in my truck and one in my boats dry box. I'd probably not use one on the bench but they are handy in a low voltage pinch (unless they don't work then they suck
Hi, Adam. Thanks for a useful video, I have had one of these reference devices for some time and recently fitted a lithium cell internally. The cell charges when the DC jack if fed from a USB source but to my dismay it discharges quite rapidly when the device is switched off, there clearly being a drain in the 'off' state. Have you encountered this phenomenon?
I don't believe that the IC mounted on this board is original as it is very expensive IC and you get the whole board for that money for such board (most of them are from 3 USD to 6 USD), I've ordered mine for 6 USD including delivery. But for some rough reference, this is excellent board.
Interesting, I brought a similar voltage reference source, in fact using the same solution AD584k. Got similar results to yours, but my cheap meter the M-830B the predecessor to your cheap meter performed considerably better. Strange considering mine was brought in 2003 and somehow has managed to hold up. I may have to go revisit my test now...
+blaser I guess two meters from the same batch could yield different results. Luck of the draw. At least I know my other meters are pretty accurate. Thanks for your comments.
Think Im gonna get this voltage source, have you measured it over time by chance ?...cheers.
5:00 "checked against what you would hope is a calibrated meter" -- apparently an HP3458A. Hopefully calibrated, as you say.
They are callibrated but I dont know if its a HP3458A.
hello ... where can I find the portapow monitor? I searched the internet and did not find
I took my Hao Qi Xin voltage reference apart today (before I saw your video) to fix a broken connection to the -ve terminal of the Lithium cell. Then I had trouble reassembling the laser-cut plastic enclosure.
I think it was designed as a puzzle. Has anyone seen the plastic M3 screws that were holding it together?
+John Cherry Crumbs! Hope you get it all back together. :-)
+Adam Welch Yeah. It was tricky because my fingers don't work as well as they used to (I have MS) but I was patient and got it all back together. I replaced the missing screws. Now I think I'll have a cuppa, and a good lie down.
+John Cherry Glad to know you've managed to get it all back together and you're still tinkering and fixing things despite the difficulties. Thanks for the update. All the best.
Don't despair. You are concerned about a degree of accuracy to the millivolt level but have not taken into account the quality of your test leads. Measure them on the ohms range by shorting them and then sit down with a calculator and pencil and paper and figure the error they crank in. It should be around one ohm or less.
It's probably why the first three do not match the standard voltages exactly. But your little cheap one is perfectly acceptable for carrying along in a tool kit to determine the car battery voltage, etc. And, in terms of accuracy, it it way better tban an old 20,000-ohms-per-volt analog meter of man years ago.
So, what with deviation at now?
Could you post a link to the voltage reference please. Thank you
+Dean Greenhough Try this for size - www.ebay.co.uk/itm/331577205821
+Adam Welch thank you Adam, ordered, appreciate the prompt reply
Not funny.
Indications on all 4 devices hop in the latest sign of not only.
Clearly gives interference switching power supply.