Multimeter Review / buyers guide: Pt 2 - UNI-T UT71D
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- čas přidán 12. 01. 2013
- Review of the UNI-T UT71D multimeter / DMM - 4000 / 40000 count, 0.025% / 0.05% DC accuracy, internal data logging for 10 000 values, PC data logging.
In this video: PC data logging software, a look inside, battery consumption and low level warning, mains measurement.
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Further discussion and picture here on my forum: mjlorton.com/forum/index.php?t...
If there is enough interest in this multimeter Franky will stock it on his eBay store:
www.99centHobbies.com
Or contact Franky for discount on my forum.
I part 2 of this review I take a look PC data logging software, a look inside, battery consumption and low level warning, mains measurement.
I use both the PentaRef and DMMCheck Plus from Doug at VoltageStandard.com
Details and specs of the UNI-T (Unitrend) UT71D:
www.uni-trend.com/UT71d.html - Věda a technologie
This is version 7 of the PCB, with major repositioning of components to accommodate bigger fuses. The current shunt has been modified and the board cut-out is also new.
Seeing how the "AC+DC" is labeled next to the DCV position, perhaps you can try pushing the yellow button after selecting DCV and see what happens.
And BTW, you have a beautiful daughter!! She's an angel :)
Gotta love your honesty in your video blogs Martin......well done!
Thanks Dave, I appreciate you feedback.
Thanks very much for the feedback and post Arne. Cheers, martin.
Hi Martin, I give an example of the AC+DC function in my video jwrelectro: "Part 2 of 4 Review Amprobe AM-140-A" at around 8:50. The reason you saw no change is because you are measuring an AC mains voltage which in theory should have no DC component/offset. Nice video!
Thanks FT! I will check that AC+DC again and might follow up with a few other bits I missed. Cheers.
True...hope to pick that up in a follow-up.
Thanks for the feedback and correction.
Again...thanks for that feedback.
Many thanks for the detailed review! I like your good work.
Good question...I hope to post a follow-up to bits I have missed and will included this if I do. I will also try test and feedback here. Cheers.
Dear mjlorton! Thanks for the video.
Thanks for the post.
Ok, I used a 1mA source and measured the burden voltage / voltage drop in both mA and uA ranges on both meters:
UT61E in uA -> 0.62V in mA -> 0.01V
UT71D in uA -> 0.49V in mA -> 0.006V
Good video, fair and honest. Just bought one.
Very good review. Thank you for the imformation!
Delvic Gudmundson My pleasure.
Thanks Ian.
Great review, Thanks you!
Thanks!
Great video, Martin! Your little one is adorable :)
Not had one in my hands yet so can't say. I'll make a note as a possible future review.
many many thanks.Excellent
Hi Dennis...sorry, I don't have a source greater than 20 Mhz.
The software does not have the option to go full screen from what I can tell....very odd.
Yes...silly me...that character could have been avoided!!!
I totally agree with you on the SD for data logging...did mention this to Comtest / Fluke and they said the have now implemented this in their power analyser...but not sure if it will move to any other meters.
First thing to change are those fuses, at least to ceramic versions same size, or bigger ones, nice to have the footprint there. CAT5 multimeter, nice for low energy circuits.
Nice review. I like more your reviews than Dave's ( EEVblog ).
I like to add the three PTC by my self.
Any idea what type will be perfect and have less leak current ?
Hi, how fast is the conductivety test (beep) , my Extech DMM is very slow on this, takes a few hundred ms before it starts beeping when shorting the terminals.
Yes, it's possible, watch the first part.
You press a button on the meter and it sends all measurements saved in a few seconds burst through the cable.
_I have the same instrument. When I measure the current voltage, it shows 10 V~ more than what the laboratory instrument measured. The voltage in my house is 235 V~, and such a UT shows 245 V~. I don't know if it is possible to calibrate without expensive equipment. Thank you._
@mjorlton..do you have bios rom for this model..i have error with my 71D
Whats the diff UT71D vs UT71E? Does the E have loging?
It is not necessary to desolder anything to remove the PCB, Martin. THe metal shrouds will pop out of the jacks with a bit of pressure applied underneath the board.
The AC+DC function is best demonstrated with a function generator delivering a square wave with a DC offset.
The PTC doesn't protect the Volt range. It protects all the other selections (Ohms, Caps, etc) against overvoltage. Have a look at the circuit schematic.
What is your Opinion on the Fluke 88V Automotive Meter ?
Great review
I am interested in frequency range do you have a source beyond 20 mhz?
I work in 200 to 300 mhz like to see what it does there also the display on pc How big is it full screen ?
thankyou
Dennis from wis.
Martin, I do enjoy all the multi meter and o'scope reviews, but also like to see something different test equipment like a EMF tester.
Buna ziua ! Știți cumva cum pot repara un multimetru UNI-T 70B LA CARE SA CRAPAT DISPLAY-UL? DE UNDE POT PROCURA DOAR DISPLAYUL.MULTUMESC.🎉
Just like the UT61E, it has unfilled spark gap positions. Coupled with glass fuses, the UT61E at least came with BS1362 ceramics (yes, only 250VAC rated, but still a hell of a lot better than little glass fuses). But again, like the UT61E, it has component positions for both a spark gap (you can use a MOV here, instead) and better rated fuses (6.3x32 and 10x38mm for the 500mA and 10A fuses respectively). So room to fit appropriate protection if you're inclined to do high energy work with it.
Coming soon...
Hi Martin.
Can you test the voltage drop (burden voltage) or internal resistance of multimeter on current measurement ranges especially in mA range. Because I now looking for multimeter with dataloging capabilities which I will use for low voltage and current measurements. So I wonder about the choice between UT61E or UT71 UNI-T series, but I read somewhere that UT61e has a large voltage drop of about 0.8V which is problem for circuits worked on low power supply voltages.
Fuses are replaceable parts. You can put ceramic fuses instead of the glass ones, there's even footprints on the pcb for bigger fuse holders.
PTCs can also be put on the board. 2 fuses and some ptcs are much cheaper than $100-200 extra for higher end meters.
Even without those modifications, this meter (in or outside its fast measuring mode) hits all your needs.
If you want extra safety, the Agilent he compares this meter to might be what you need, but it's not cheap.
I wanted a meter that did AC+DC True RMS and had logging capabilities but my budget was extremely limited. I just bought the UT71D from eBay for 123€ shipped. Not impressed with the protections but I will be using it on ELV levels so I'm not too concerned. Also, I could be lucky and get a revision with proper fuses. Thanks for the very detailed review!
Did you check the fuses?
Mine came with glass fuses too. It's been working fine for my needs though this past year and a half
I think now all UNI-T's multimeter come with ceramic fuses.
Any flows?
2022.April.17 = UNI-T UT71 E with production date: 04/2021
My Uni-T UT71E comes with 2 ceramic fuses .
(10 Amp from Holley ist very long and thick and a lot of sand volume inside to stop a spark)
(500mAmp fuse is the maximum size the PCB connections allowed by the manufacturer)
The 2 crocodile cables are not includes.
In my country these version is not safe to use
(when an beginner connect these on extreeeem high voltage or current because he is not a electric/electronic skilled person)
No extra three PTCs are mounted.
Additional informations = Sorry my english is not perfect. I am german.
And by the way the CD is not included.
The warranty card is not from UNI-T as in the video part 1.
The UT71E PCB is a little bit different , but quite identical. Ok not really identical.
Сool review.
Hello Martin! It would be great, if subtitles were available. I understand english, but not 100%. I think that this could add much more views to your videos, with subtitles. I don't know if you can enable it, or what. Kind regards.
dangit uni-t a pretty nice meter killed for me by lack of input protection
Como pode a uni-t fazer um instrumento tão bom e colocar um fusível tão medílcre??
01 PTC de proteção 🤒🤒🤒
34:40 Very lovely :-)
Go on then, go design one of these meters and market it. Give us a shout when it's on sale, yeah?
At least the battery clip is of the hard variety, rather than the flimsy, soft ones which only ever come off one terminal at a time.
how can uni-t make such a good instrument and put such a bum fuse ??
I'm intelligent enough to see many opportunities for betterment of this world. That doesn't logically mean I'm obligated to do every one just to free people like you of the burden to think.
For me here in Germany its about 160 Euro.......I better safe for a Agilent U1272A.
I also have a cheap peachtek and after 6 years the paint of the resistors is falling off and one of the resistors is even breaking? from nothing .
It looks like the blue button seems to have a second use for monitoring a 4-20 mA process control loop. You didn't mention that function.
well no thanks :) I did see it on diff. pages and it seems to me it isn't very good at all. even my old Mulimeter Metex had big ceramic fuse..and not that thing :) What i would like to see is good multimeter with dataloging and fast speed. and ofc good voltage protection.i don't want spend few thousands but i want spend some decent money for good multimeter. So Any advise? I did like this dataloging..but general quality wasn't good all.
on the back case it says the exact same thing, no different
There's no performance difference between the RS232 cable and the USB cable. The interface is exactly the same, the USB cable simply has the adapter built in.
WOW, seems like a 3chip solution is not a good idea.
There's a Holtek LCD driver chip inside, a variant of a MSP430 (In a SOIC or TSSOP small chip) and a main Cyrustek ASIC
The UT61E only draws
I don't think it's fair to compare multimeter pricing to tablet computes. They are produced (and sold) in massively different volume.
multmeter review pt 2 argh
The build quality looks dissapointing. I have just opened up my old UT70D to compare that is significantly better (proper fuses, screw connected input connectors, better soldering, more shielding etc)
The girl is cute 😄
meters are rather stagnant in tech like calculators and watches.
at this price point we should really see some serious oscilloscope functionality on a very nice display. it's a great opportunity for a company like UT to shame the big dogs and steal market share and credibility with a must have DMM.
an obvious approach is a buttonless touch screen device. just display and connectors. 60MS/s and 10MHz bandwidth. 150$ price tag. base it on a calibrated UT61E 22000 count with autoranging plus scope.
not logic problem, reference problem
A part for 30 minutes can laugh.
nah that doesn't really matter. the chinese don't have big development or startup cost. they can hammer out tablet computer in short order.
and there is no big parts discount from 10000 to 100000
I sort of like the meter but the price can't really be justified. yes it's half price of a fluke or agilent but those are not real references. those are massively overpriced as a matter of greedy corporate policy.
it's twice the count of 61E and has a bigger display, more features and a light. but is that really a 100$ price difference for a company like UT... I think not.
you can get good 7 inch tablet computers for that price and that's a very different class of tech.
By your choices you ask the truth to insult you
Looks way worse than UT-70D. Almost like a joke.
And he immediately resorts to personal attacks! What a shocker.
Here's what I think: If you've got so much knowledge of the design of these devices, of the prices, and so many ideas on how to improve them, stop whining on CZcams like a little girl about how nobody is making the device you want and GO MAKE IT! Stand up and DO SOMETHING YOURSELF. If it's actually possible to do what you say, then someone will fund you. Get on with it.
Thanks!