Groupbuy for UNI-T UT210e clamp meter for tailcap current readings

I sent a rather low-ball offer on this model, we’ll see what he says.

PD68 wrote:

ImA4Wheelr wrote:

Build one of these and you won’t look back:

https://budgetlightforum.com/t/-/26092


I swear I’ve read that thread 20 times over the last couple years, and I just don’t get it. Also it’s clear I need a reliable meter to tune in the new shunt, which I do not have.

I used a bench top variable power supply to make mine. I don't know how accurate the meters on it are, but it's all I have to go by. I just cut a 6" 14ga wire with an inch of insulation stripped from each end. I then put the wire in the power supply and then ran 10amps of current through the wire. I then probed for the spots that gave me 10mV. I then soldered wires to spots just a tad wider than those spots because the solder reduces resistance a tad. You can then tune the wire be either notching the wire or adding solder. You have to let the wire cool from soldering before testing it for accuracy.

My version, banana sockets are to plug a multi-meter (set to mV range):

22 AWG wire for shunt, about 8” gives 10 mohm (so 10 mV/A). Trim exact length by using an amp meter in series with the shunt and a voltage source. Going over 10A you should probably use thicker wire and lower resistance for the shunt, as per the linked thread above.

Note that copper wire has a relatively high tempco re. resistance. There will be a 4% change in shunt resistance with every 10 C change in temperature. Proper shunt/resistance wire is manufactured from alloys with much lower tempcos.

These are made with Nichrome wire where the resistance increases as the wire heats so I wouldn’t go there. They will handle a lot of current though, just not accurately until the temperature settles down. These were used to compensate for lower battery voltage while the starter motor operated, then lowered current afterward to make the coil and contact points last longer.

Phil

was undecided between that 210E (24-28 USD) (because of the 1mA resolution, I prefer precision for what i do than 500+ Amp capability), the Mastech MS21080-35 USD (the cheaper 2108A version has not TrueRMS and no Inrush current 27-30 USD) but in the end I opted for a 216C for no reason…. (as always), well the reason was mainly because it seemed a bigger discount even if i ended spending more of what i had planned…47 euros shipped tskk . Always speaking of DC current clamps

It was able to detect 8mA (the clamped displayed 0.01A) And testing various low currents with my linear variable PSU i got very very decent results
But somehow i was not able to measure the battery drain of my sister Toyota Yaris with headlights on, I whink they should absorbe near 9Amp, dunno why

Instead , don’t know if it was reliable for instantaneous DC current (because it calculates the inrush current doing the Fourier transfor of a variable current) i was able to measure 466 Amp from the same yaris D4D to start the engine (battery rated for 570Amp cold start, so it could well be)

If you need me to check something just ask, i’ll do what i can while i’m not at work

I was also looking for one last year too. My budget is enough for Uni-T only. 210E seem to be a good choice for measuring Amp consumption for flashlight. 211 cost almost double of 210.

More precise resolution would be nice, but probably not necessary. I can always use my normal meter for the lower stuff.

I don’t think I’ll ever measure AC with it, so I’m probably ok without the TrueRMS feature?

Can your wizardry get us a fantastic deal on the 210e?

Well even if you need to measure AC… Until it’s a standard sine wave like our common AC we have at home… You are really ok.

Truerms is something I probably never come to use since it’s used for different waveforms.

If you look at your dmm at home you will notice it will measure AC but it’s not trueRms…

I took the 216C mainly for the inrush function… The trueRms it’s a plus… If it is real lol

I’m really not even sure what “inrush” is.

I’ve seen some discussions about “zeroing” vs “relative” but I’m not sure if that’s something I need to look out for

Yes the zero function is something you have to look for. Because usually clamp do add some offset in the value because of environmental factors and other stuff. So, zeroing will put the displayed value to zero, before you take a measure. Some clamps do not have the zero button but once you go back to a different setting and forth to the AC they “self zero-ed” themselves… So just look for a YouTube video… Or even better search for a review in a competent site like eevblog or such.

The inrush is used for AC measurements (at least in mine) and in simple terms measured something similar to the peak current in its first 100ms(in mine model).

So for example you can set the clamp to inrush mode leave it there alone and go powering up a system, go back to where you left the clamp and see the absorption peak of the system while it started.

I think it differs from the simpler peak because after it has monitored something when firstly the current arrive it stores the data and not continues to monitor for a higher value.
Also the calculated current should be done by an integral and not just by looking for the highest value… This could be bull@hit from my imagination I’ve should have read them somewhere but I’m not sure… So if you want you have to research and scrutinize better

Hopefully I made myself understandable, sometimes I read what I wrote few minutes earlier and I can barely understand it myself… Lol

We could definitely do that If we could all agree to one or two model?

Primary use of the clamp is for flashlight measurement and serve as a back up DMM at the same time? Which models are worth considering?

Inrush current - Wikipedia.

I think if you have to be on the 28-38 use budget and have DC current (for flashlights obviously) there are not many models and a lot are just rip off of the one I mentioned earlier

The 210e has good reviews and a nice starting price point, but I’m open to others. I think the most important thing be that it is accurate and consistent in the 2-20 amp DC range. It would be sweet to do a small groupbuy on something, but I’m hoping to order something in the next week or two, to make sure it makes it out of China before new years

Shouldn't be difficult to get 201E under $30. Any more takers?

TheBo do you agree the 210e would be good for our purposes? It has the 2amp range that some others don’t have. It gets 4.9 out of 5 on Amazon with 26 reviews, and it’s nice and compact.

Freeme: you think we can do a fast turnaround time on this one?

Yes, it was my first choice, but remember, I’m a hobbyist so asking to me is like asking to a buddy.
Anyway I’m really curious to see the GB price if this will received the due attention. Too bad I already spent more than what I needed

Also note, if you don’t now what it is… That the 210e has 2000 counts
This means that a value of 1.999 will be displayed as 1.999
A value of 2.001 will be displayed as 2.00

Just FYI

Also note that, technically, resolution doesn’t mean accuracy… This means that something (hypothetically) could be more spot on (regarding accuracy) than something that has more displayed digits (resolution)

But generally resolution comes handy when you have to see small changes

After reading this thread I remembered that I’ve thought about buying a clamp meter before. The 210E seems to be a good choice so I’ve bought one from the Tomtop store (Tomtop.com with warehouse in Germany). Currently on offer, the price seemed to be ok and delivery should be faster compared to other China stores.
The accuracy for DC current is listed with 2%, not bad compared to other models in this price range. I would have spent some more for the MASTECH MS2115B (on offer in a German store for 55 Euros, but it has only a 40A range and higher. Although 6000 counts and an USB port… The PC interface could be used to do measurements of charge/discharge currents over time.

my 216C from their uK warehouse , untracked delivery took about 10 days