Author Topic: A look at the Uni-T UT210E  (Read 437353 times)

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Offline mos6502

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Re: A look at the Uni-T UT210E
« Reply #50 on: March 24, 2016, 06:09:13 pm »
I love watching/reading reviews so if you do get CP-05 please make a post.  Perhaps making a CP-05/CP-06 thread and moving our posts there wouldn't be a bad idea.  I don't want to disrespect the OP by cluttering up the UT210E thread.

Nope, sorry, I just bought the CT238 (which is identical to the Fluke i30): https://www.eevblog.com/forum/testgear/list-your-test-equipment-score-here!/msg901296/#msg901296

But I agree, we should start a separate current clamp thread.

The spec for CP-05 a bit confusing to me. It says Min resolution is 1mA then below that it says Output sensitivity on 4A range is 10mA/1mV.   Can it measures low Currents below 10mA?

The CP05 has similar specs to the Fluke i30 and on that one, they give 5mA as the minimum usable current. I think that's what you can expect.
« Last Edit: March 24, 2016, 06:11:36 pm by mos6502 »
for(;;);
 

Offline Circlotron

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Re: A look at the Uni-T UT210E
« Reply #51 on: March 24, 2016, 09:43:43 pm »
The magnetic core is actually insulated on the business end of the clamp, which surprises me. I thought, especially for a clamp that can measure down to such low currents, you would have to make sure your magnetic loop is as much closed as possible.
I expect that if the core was completely closed, that is to say, the metal ends were touching, it would saturate very easily when measuring DC currents. Bit of a compromise between low end sensitivity and high end range. But then, there must be another gap in the core where the sensor is sandwiched.
 

Offline Macbeth

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Re: A look at the Uni-T UT210E
« Reply #52 on: March 26, 2016, 05:12:28 am »
Took at look at mine and the data sheets.  Seems like we could add RS232, which for me would not be very helpful
Au contraire! Fitting a BLE module would make this already excellent meter way better. Why? Because getting the bastard to perfectly sit and read DC current AND be visible while working on a loom of cables in the cramped footwell of a car, for example, is a nightmare.

A remote readout is a perfect application for this meter! I did it with a Vichy 99 but this one is far better! .. off to read the datasheets...  :-+
 

Offline joeqsmith

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Re: A look at the Uni-T UT210E
« Reply #53 on: March 31, 2016, 04:39:08 am »
Op-amps made it in yesterday.  Won't be too much longer and we can see how well this is going to work. 

Offline flywheelz

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Re: A look at the Uni-T UT210E
« Reply #54 on: March 31, 2016, 06:50:55 am »
Op-amps made it in yesterday.  Won't be too much longer and we can see how well this is going to work.

 :-+ Oh the suspense, I am checking this thread daily  :scared:
 

Offline 3db

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Re: A look at the Uni-T UT210E
« Reply #55 on: March 31, 2016, 04:39:46 pm »
Op-amps made it in yesterday.  Won't be too much longer and we can see how well this is going to work.

Can't wait to see this.
I wonder if this meter will be spared the mighty transient generator.
« Last Edit: March 31, 2016, 04:42:19 pm by 3db »
 

Offline joeqsmith

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Re: A look at the Uni-T UT210E
« Reply #56 on: April 15, 2016, 03:47:14 am »
After spending some time looking at the 210E here's what I am thinking as far as adding an oscilloscope output.   If you are a script kitty of the hardware world and have no desire to learn or do anything on your own, read no further. 

Safety
First I would not consider the 210E a safe device.  Making mods to it could indeed make it safer but if you were harmed while using a modified device, I doubt this would help your case.  Of course, modifying any device could also make if VERY dangerous!!!  Because the 210E is not only a clamp but also has other functions that use leads I can see problems even without doing anything to this meter.   The area around the inputs is very tight.  Adding another connector in this area is just going to make things worse.  Also, adding another connect and still having the banana jacks, I can see causing all sorts of problems.   Imaging someone hooking the leads to their AC lines then connecting the clamp to their scope.  It seems a better approach is to not to have any banana connectors and remove everything except what is required for the clamp.    The safest approach I can think of is leave the meter in the original packing and return it for a refund.   For the rest of us, we push on....

Robustness
Well, it is a UNI-T. I am sure a few of you are aware that I have damaged my fair share of this brands products.  That said, if it were just a clamp you would not need to be concerned with the inputs.  Still, say if we were to use the banana jacks for an output.  You know that someone will forget and hook it back up to the AC lines.  It may need to be hardened against things like people hooking to the output of their microwave oven transformers secondary because you know someone will do it! 

Test setup
I used a function generator that drives a FET that uses an inductor in series with a resistor as a load with a DC supply.  I just wanted a ramp (assuming the inductor doesn't saturate).   I was pulsing this with a very low duty cycle at a low frequency.   Mine was a 2ms pulse once a second.  This is just so I had some way to inject a known signal.   In my case I have once channel of the scope attached across the loads resistor to monitor the current and act as a trigger.  I set it up for a 1A peak.  The scope was then grounded to the common banana jack.  This will act as the reference.   

Where to probe
Looking at the circuit, you will see an 8-pin quad op-amp (U4).  This is a TI OPA4330 chopper.   All four appear to be in use.  If you probe the positive and negative supply pins of the chopper, you will note they are above and below our reference.   If you then probe pin 14, you will see the current signal.   You can follow this around on R7 and L3.  You will also see it on R11-R14.   You will note that as you change the range the amplitude on at R7 will change.  The AC/DC and offset buttons do not have any effect on this signal.   

Op-amp choices
If you wanted to buffer the signal to drive your scope it seems parts are pretty limited.  Obviously, we have the 4330.  The INA333 may be another one to look at.   You only have the 2XAA batteries as a source and these parts will run down to 1.8 volts.   

Other
There is more than enough room to add an isolation barrier and a mezzanine for the buffer and protection circuits, maybe.  Things are tight.  You really have limited choices where you could put anything inside the clamp.  Near U4 certainly appears to have the most room.   Adding an offset trim in hardware may seem like a good idea, but the scopes offset could be adjusted instead.   

Performance
Don't expect much from a $40 probe.   I have a very old Tektronix P6042 current probe that I posted about where after repairs had increased the BW from 50 to near 100MHz.  One of the things that came out of this was I had made up some different jigs to inject the current into the probe.   Test1 & 2 show the jigs.  I ended up just using the wire for these tests.

Test 3 is showing the inductor/resistor being driven from a pulse.   C2 is the voltage across the shunt and C1 is the output from the 210E.

Test 4 the inductor was removed to increase the edge rate.   

Test 5 using the loop, the clamp was connected to the network analyzer.  I attempted to run a sweep from 100Hz to 300KHz.   The cursor is around -3dB and 5KHzish.

Test 6 shows a 100 to 10KHz sweep.   Cursor is again at -3dB ish. 

Hopefully for the few of you who are interested in adding a scope output feature, this give you some ideas on what to expect and how to go about it. 

Offline joeqsmith

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Re: A look at the Uni-T UT210E
« Reply #57 on: April 16, 2016, 03:28:47 am »
Using an SMB to pass sub MHz. :palm:  Then putting a nice conductor like this right between the two banana connectors would be VERY unsafe!!   Notice too how there is full access to the original banana connectors.  So again, the leads could be connected to something really deadly and there is that nice conductor sitting right next to the end of the handle!   :palm: :palm: :palm:   Adding some rubber plugs to cap off the banana connectors may not be the worst thing. 

The BW is just so poor and the device already has a meter on it,  I can't really come up with a reason now to even attempt the mod.  It may be a case where the benefit does not out weight the risk.   I think if someone were to want an analog output, the best thing may be just to buy a probe that has it rather than attempt to modify one.   

Offline 3db

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Re: A look at the Uni-T UT210E
« Reply #58 on: April 16, 2016, 11:15:31 pm »
Took at look at mine and the data sheets.  Seems like we could add RS232, which for me would not be very helpful
Au contraire! Fitting a BLE module would make this already excellent meter way better. Why? Because getting the bastard to perfectly sit and read DC current AND be visible while working on a loom of cables in the cramped footwell of a car, for example, is a nightmare.

A remote readout is a perfect application for this meter! I did it with a Vichy 99 but this one is far better! .. off to read the datasheets...  :-+

Check out Kerry Wong's Youtube Channel.
He added RS232 to a meter recently.
It uses the same chip.
He also did a translation of the Data sheet of the DTM0660.
Hope this helps.

3DB.
PS how do I use the emotes ?


 

Offline crispy_tofu

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Re: A look at the Uni-T UT210E
« Reply #59 on: April 17, 2016, 03:32:42 am »
PS how do I use the emotes ?

Unless you're on Tapatalk, you should just be able to click on the emoticons above the reply box and they'll insert automatically into your reply.  :)
 

Offline 3db

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Re: A look at the Uni-T UT210E
« Reply #60 on: April 17, 2016, 07:13:23 am »
PS how do I use the emotes ?

Unless you're on Tapatalk, you should just be able to click on the emoticons above the reply box and they'll insert automatically into your reply.  :)

Thanks for that.  :D
 

Offline macboy

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Re: A look at the Uni-T UT210E
« Reply #61 on: April 19, 2016, 05:59:04 pm »
Based on the information at Kerry Wong's website, I was able to make a little modification to this meter: 6000 counts instead of 2000. Pics or it didn't happen? See below. I didn't show pics of clamp meter current measurement, but they get 6000 counts too.

I was not able to enable RS232 output; the bit is already set in the EEPROM, but the long press on REL does not do the trick. I have another DTM0660 meter besides this one, and I also could not enable RS232 on that one; the required output pin was already being used for another function and the meter stopped working if the associated bit was set in the EEPROM.

The details of the 6000 counts mod are pretty straightforward. The EEPROM contains data at specific locations to tell the meter when to auto-range up and down. These are set to 2200 and 190 respectively. I simply set these to the default of 6200 and 580, so that the meter stays in the lower range until over 6000 counts are displayed. Simple. Refer to the translated data sheet on Kerry Wong's site. Note that I found that I needed to remove the EEPROM to write to it, since it is connected directly (no series resistor) to the DTM0660, and it was preventing me from driving the signals to talk to it in-circuit. Note that UNI-T does sell a 'better' version of this meter with 6000 counts, and at over twice the price.   ;D
« Last Edit: April 19, 2016, 06:02:43 pm by macboy »
 

Offline joeqsmith

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Re: A look at the Uni-T UT210E
« Reply #62 on: April 20, 2016, 02:38:32 am »
 :-+  Wow, 6 Amp clamp with 1mA res!  Very nice!


Based on the information at Kerry Wong's website, I was able to make a little modification to this meter: 6000 counts instead of 2000. Pics or it didn't happen? See below. I didn't show pics of clamp meter current measurement, but they get 6000 counts too.

....

The details of the 6000 counts mod are pretty straightforward. The EEPROM contains data at specific locations to tell the meter when to auto-range up and down. These are set to 2200 and 190 respectively. I simply set these to the default of 6200 and 580, so that the meter stays in the lower range until over 6000 counts are displayed. Simple. Refer to the translated data sheet on Kerry Wong's site. Note that I found that I needed to remove the EEPROM to write to it, since it is connected directly (no series resistor) to the DTM0660, and it was preventing me from driving the signals to talk to it in-circuit. Note that UNI-T does sell a 'better' version of this meter with 6000 counts, and at over twice the price.   ;D
 
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Offline flywheelz

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Re: A look at the Uni-T UT210E
« Reply #63 on: April 20, 2016, 04:38:29 am »
2000 counts is one thing I did not like about this meter and now I see a 6k mod  :-+ thx macboy.

macboy, I am hoping I don't have to pull the eeprom  :scared:  Confirming, you tried attaching external 5v to VCC and through 10k resistors to SCL/SDA and it didn't work?
 
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Offline mimi123

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Re: A look at the Uni-T UT210E
« Reply #64 on: April 20, 2016, 07:25:48 am »
I'm going to buy a clamp meter and I have in mind this model. I think is perfect for me with only one caveat.

I'm concerning about maximum current capability. I normally don't measure more than 50 amps but little times I want to measure the consumption of some high power car audio amps in the range of 150 amps.

Did you test with more than 100 amps?
Did the unit go to outrange?

Very thanks
 

Offline macboy

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Re: A look at the Uni-T UT210E
« Reply #65 on: April 20, 2016, 11:31:23 am »
2000 counts is one thing I did not like about this meter and now I see a 6k mod  :-+ thx macboy.

macboy, I am hoping I don't have to pull the eeprom  :scared:  Confirming, you tried attaching external 5v to VCC and through 10k resistors to SCL/SDA and it didn't work?
Yes, I tried, using a bus pirate connected to the 5 pin header on the PCB (see photos earlier in the thread). The BP could snoop the bus and see valid transactions whenever the unit was turned on or function was changed. When trying to read or write, the BP always complained about the lines not going high. Unfortunately the microprocessor seems to drive those lines low when not actively talking to the EEPROM... It does not float them like it should. So I pulled and reinstalled the EEPROM (a few times). I used a TL866 and a SOIC test socket to read and write it.
 

Offline joeqsmith

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Re: A look at the Uni-T UT210E
« Reply #66 on: April 20, 2016, 05:29:15 pm »
There appears to be a small catch the the 6000 count mode.   If you are using the DC current mode and zero out the offset, the range appears to revert to 2000 counts.   A quick glance over Kerry's translated data sheet, I do not see a way around this.


I'm concerning about maximum current capability. I normally don't measure more than 50 amps but little times I want to measure the consumption of some high power car audio amps in the range of 150 amps.

Did you test with more than 100 amps?

Being a $40 clamp, there is no degauss circuit.   The only thing you get is the pot near the flat ribbon appears to trim the DC offset.   Well, you get the software zero button too.     

If you hold a magnet between the clamp, it will cause the parts to become magnetized.   I tried it and was then able to degauss it, set the trim and it's a little closer now than when I got it.   

I think if you put over a 100A through it, worst case you would have to degauss it.   I do not have a power supply large enough that I can put out a known DC current  over 100A.  The largest I have is only 40A.    So, I stuck it across my DC welder with the leads shorted.   The meter showed over range but I have no idea what the welders current looks like or how much it was.   I can tell you this was enough to magnetize it again and required it to be degaussed.   No damage.     

I then tried it with AC mode but the with the largest toroid I have, the best I could do was 85A.   

Found some larger cable and at least in AC current mode, it looks like it trips at 100Amps.  At 0x1C I see a 0x0A in my PROM.  I wonder if this is scaled for the 100A limit. 

« Last Edit: April 20, 2016, 05:56:12 pm by joeqsmith »
 
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Offline mimi123

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Re: A look at the Uni-T UT210E
« Reply #67 on: April 20, 2016, 06:48:43 pm »
Very thanks joeqsmith for your help.  :-+

Maybe if the clamp becomes magnetized we can degaussing it simply measuring AC current, it makes sense this?

It's a good idea to hack the PROM to avoid the limitation on the 100A scale. If someone find the correct value to write to the EEPROM please post it.

I see, at the manufacturer web, there is another model (LT210D http://www.uni-trend.com/en/product/2014_1127_1026.html ) can measure up to 200A but did not have the 2A scale and we lost the 1 milliampere resolution. May be the current sensor is different or the UT210E has a better opamp.

I'm going to order one unit, I think it would be very useful to me and the price is not too much.
 
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Offline flywheelz

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Re: A look at the Uni-T UT210E
« Reply #68 on: April 20, 2016, 09:38:58 pm »
There appears to be a small catch the the 6000 count mode.   If you are using the DC current mode and zero out the offset, the range appears to revert to 2000 counts.   A quick glance over Kerry's translated data sheet, I do not see a way around this.

Does it revert back to 2k temporary and power cycle gets you back to 6k?

I wonder whats at 10h, 11h.  Maybe it uses that when you zero out?
 

Offline joeqsmith

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Re: A look at the Uni-T UT210E
« Reply #69 on: April 20, 2016, 11:29:18 pm »
Any time it is in DC current with it zeroed, it will be in 2000 count mode.   Holding down the ZERO button will turn this feature off and the meter will revert to 6000 count.  I am not thinking this is a real 2000 count.  Once you zero it out, it seems the offset is added with the overflow.  So for example with the 2A range selected and the meter zeroed,  I may read 2.4nn A and -2.5xx before it rolls.   It appears like the range is +/-2.5 offset with the zeroed value.   

0x10 - 0x70
0x11 - 0x17

So 0x1770 or 6000 decimal

Below is the entire EPROM contents for mine in raw format: 

FFFFFFFFFF0080E803E803FA0000BE03
70179808BE003D3D3C3CFFFF0AFF40FF
879806816400960000801780FB7E3875
4E0209EE030913010B7A120A92040A00
00010001000798006400640064000000
FE7A1C77008000800000000001000000
E37F487E0100AD2A0000000000000000
617F0080A97FE07CE605000000000000
0000000000000017000000191E1B0407
000000000000001600000018001A0509
0000000000000000000000000000000A
0000000000000000000000000000000B
0D0002300D0003202000032020000310
4100030841000305410003050D000230
008000800080008000802D02BE033005
2F02C1033F0500805AC7EF0F0F800000

There appears to be a small catch the the 6000 count mode.   If you are using the DC current mode and zero out the offset, the range appears to revert to 2000 counts.   A quick glance over Kerry's translated data sheet, I do not see a way around this.

Does it revert back to 2k temporary and power cycle gets you back to 6k?

I wonder whats at 10h, 11h.  Maybe it uses that when you zero out?
 
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Offline joeqsmith

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Re: A look at the Uni-T UT210E
« Reply #70 on: April 20, 2016, 11:43:18 pm »
No problem. Glad to offer what I can.  When I hit the probe with the welder, I am guessing I drove it into deep saturation.  I am not sure how much AC current it would take to recover it.  I just used a large coil attached to an auto transformer.   

Very thanks joeqsmith for your help.  :-+

Maybe if the clamp becomes magnetized we can degaussing it simply measuring AC current, it makes sense this?

It's a good idea to hack the PROM to avoid the limitation on the 100A scale. If someone find the correct value to write to the EEPROM please post it.

I see, at the manufacturer web, there is another model (LT210D http://www.uni-trend.com/en/product/2014_1127_1026.html ) can measure up to 200A but did not have the 2A scale and we lost the 1 milliampere resolution. May be the current sensor is different or the UT210E has a better opamp.

I'm going to order one unit, I think it would be very useful to me and the price is not too much.
 
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Offline mimi123

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Re: A look at the Uni-T UT210E
« Reply #71 on: April 21, 2016, 10:06:22 am »
Model  UT211B has 6000 counts and is DC current capable.
It would be helpful to have access to their ROM data.  ;)

I have ordered mine, hope it arrives soon.
 

Offline mimi123

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Re: A look at the Uni-T UT210E
« Reply #72 on: April 21, 2016, 02:28:43 pm »


Here and here I find some information about ROM data for modding the UT210E.

But sorry, I don't understand this language.

I hope it will be useful for you.
 
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Offline macboy

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Re: A look at the Uni-T UT210E
« Reply #73 on: April 21, 2016, 06:26:38 pm »


Here and here I find some information about ROM data for modding the UT210E.

But sorry, I don't understand this language.

I hope it will be useful for you.
Wow, those crazy Russians extended it to 9999 counts  :-DMM   They say "inclusive of 2 A mode". So maybe they worked out the bug with the zero on 2 A mode which reverts to 2k counts. I'll need to try this one out. They are changing lots of stuff in the 0x80 to 0xBF region which is not documented in the DTM0660 datasheet.

I'm thinking of mounting my EEPROM at a slight angle so the pins 4 to 7 (Vcc, WP, SDA, SCK) are lifted about 1 mm off the board, and pins 1-4 remain securely on the board. Then I can bridge the gaps with solder for normal operation or wick the solder out to attach leads for programming.

They also changed the order of the measurement functions so that DC is default instead of AC for all current and voltage ranges. I like this, since I will be using this mostly at the bench for DC, not for AC things.
 

Offline macboy

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Re: A look at the Uni-T UT210E
« Reply #74 on: April 21, 2016, 07:54:22 pm »
As above, I lifted the front (pins 4-7) of the EEPROM a little, just enough to remove the solder bridging the pins to the board. Then I soldered 5 cm long wire-wrap wires (30 ga Kynar) to the leads, soldered those to a 5-pin socket. Then I use breadboard jumper wires from that socket to a 8-pin DIP machine pin socket placed in the TL866 ZIF. It's less complicated than it sounds. I reprogrammed the EEPROM with the Russian hacker's data deltas (as below) and ... boom! Well, no, no boom, just a 9999 count meter. The issue of 2000 counts on the 2 A range (only that one) when using ZERO remains unfortunately. Besides the 9999 counts, the other change is defaulting to DC for all volt and amp measurements.

AddrOLDNEW
10 70 10
11 17 27
12 98 0F
13 08 27
87 17 16
8B 19 18
8D 1B 1A
8E 04 03
97 16 17
9B 18 19
9D 1A 1B
9E 05 04
FC 0F 00
AE 00 05
BE 00 06

Note address FC is the backlight timeout, and 00 means do not time out (never turn off automatically). Otherwise, the value is in seconds. I set mine to 1E (30 seconds). Make sure to archive a copy of your unmodified EEPROM data.

I don't remember if there was a millivolt range in either DC or AC previously, but there is not now (0.000 V to 9.999 V is the lowest range). Can someone check?

edit: Added mods at offsets AE and BE to enable DC and AC mV ranges.
« Last Edit: April 22, 2016, 12:47:03 pm by macboy »
 
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