UNI-T UT210D/UT201E Digital Clamp Meter True RMS Voltage Resistance Capacitance Multimeter Temperature Measure Auto Range Electrical (ABS)

Product Information

It included the DMM, a pair of probes, a pouch and a manual (Both a English and a Chinese version). This will read the original EEPROM image, bin/orig.bin, and produce the modified image, bin/mod.bin. To read and write to the EEPROM, ch341eeprom[3] must be present. Dependencies Hardware Further it is possible to switch the selector on 20A, to press the ZERO button and to nullify indications. At the same time the instrument in hand not to hold, give time for that that indications calmed down, to place the instrument where least of all el./magn. noises and the more so far away from magnets. Connect and fasten the SOP8-DIP8 board to the CH341A programmer. The SOP8-DIP8 board pin 1 should be farthest from the USB connector and adjacent to the fastener so as to align with the 24CXX DIP8 outline on the programmer. Changing the PROM will not impact the drift.I suspect you could run 100 of them an they would all drift roughly the same.I suspect you two main problem will be temperature and placement.When Maxlor posted 10mA in a minute, I can believe it.When I ran that test I was careful to try and hold the temperature as tight as possible and not move the clamp.

The circuit board has some input protection with two PTC's and 3 MOV's. The input resistors (R37A, R37B, R37C, R37D: 4x2.5Mohm) is split into 4 resistors, between these resistors and the input is a PTC. There is a voltage clamp made with two transistors (Q4, Q9), it is not directly connected to input or output resistors but is probably switched in depending on range. To wait. To wait long and not to hurry. To wait so far there will pass all self-tests until squeaks, then still to wait and wait for the moment when there are changing indications of the millivoltmeter. I.e. when the self-test will be completely passable, it will take ~ 2-3 minutes. The CH341A flash programmer is connected to the computer via USB and to the UT210E EEPROM via SOIC8 test clip cable. Once connected, ch341eeprom[3] can read and write the binary flash EEPROM image. The contents of this repository are licensed under the MIT license, except where otherwise noted. ReferencesCable position within the clamp does not matter btw. As long as the cable goes through the clamp, you get the same measurement.

There are two larger chips. The one on the left is a TI OPA4330 quad opamp (Markings: TI O4330A 44K G4 AN50), the one on the right is the Hycom DMM Chip (Markings: Hycom H203 DTM0660L R3MR81A) They only work with high currents. The lowest range on many devices is 20A or 40A, which gives you 10mA resolution. The circle with the arrow indicates auto power off, holding down the SELECT button during power on will disable that. They don't measure DC current, only AC current. Sometimes they claim DC current capability, but upon closer inspection you notice it's using the leads, no the clamp. When using the NCV function the display will show a number of -, depending on the electric field. This can usual be used to see if a mains outlet or cable is powered or trace a cable that is just under the wall. This function is always a guideline and not a 100% confirmation of voltage or no voltage.

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Zero: Save the current measurement and show the following measurements relative to that value (Very important for DC clamps).

A full set of teardown pictures are here. https://photos.google.com/share/AF1QipPykJgrz2vMySXTkFdst6YsfoTs0Mzs1vmWZXa-XQ5EGBxVeRmFiqj-jO2c44IFcA?key=T01ITXVCa015U0x5WV9UZUV6dUdiSGdXUTBENF93 One this side is another string of resistors (R27A, R27B, R27C: 3x300kohm), but strange enough they are connected directly to the input terminal without any protection. The NCV voltage led (LED3) and the transistor to drive it (Q2) is also placed here. Velmi šikovný malý "klešťáček" pohodlné ovládání všech prvků jednou rukou, kolečko jde lehce a přesně bez "přeskoků", dostatečně velký displej s podsvícením a velmi dobrou čitelností ze všech úhlů. Měří docela precizně, (ten můj má dokonce mnohem lepší tolerance, než uvádí výrobce) super vychytávka jsou tři rozsahy měření proudu, "pípák" reaguje celkem rychle, stejně tak i automat při přepínání rozsahů. Jedinou maličkou chybičkou jsou výrobcem dodávané měřící kabely, sice nejsou už tak tvrdé jako je běžné u těchto levných měřáků, naopak, jsou ohebné tak akorát a nemají tendenci se zamotávat, ale jsou z nějakého měkčeného plastu, a ne příliš teplu odolné, koncovky mají zahnuté o 90° což je k této konstrukci měřáku se spodními vývody naprosto nevhodné, niklované hroty tomu taky nepřidají a miniaturní gripy působí velmi nejistě. Ale protože používám jiné měřící kabely, musím říct, že měřák jako takový je velmi povedený a za ty peníze přináší opravdu hodně "muziky". Connect the SOIC8 test clip cable to the SOP8-DIP8 board. The red wire should be connected to pin 1.The clamp claims Cat II 600V and Cat III 300V, and opens to about 16mm, which is plenty. The movement has no play and feels solid. Between 15N and 20N of pressure is required to open the clamp.

REALLY happy after all of the Chinese crap I requested and reviewed. Finally--got a nice clamp meter for DC current and work! Stoked. There are no major transmission lines visible from my location, and local power is distributed via underground wires. I took the meter outside and tested in two different locations separated by 100 feet or so. Before being zeroed, the meter reads in the 320-430mA range. After zeroing the meter, I tested variability based on orientation. Slightly rotated and tilted up and it read 130mA . Tilted it down, -75mA. The variation was similar when tested in the other location. (Biggest change tends to happen when tilting up vs down.) So today, outside, the variation is around 210mA. I saw earlier in the thread that the meter could become magnetized and require degaussing. I understand this could cause an offset in the reading, but it's not clear to me if it could also cause the variation based on orientation that I'm seeing. Also, I'm not sure which of my power tools or appliances would leak enough EMF to use as a degausser. Close to the MOV's is a EEPROM (IC2: 24C02A) for parameter storage and some calibration, there is also trimpots for calibration.So my question is is this typical behavior for the meter, or should I exchange it for another? What do others see? I recorded video of process of resetting to zero of the current indications in the DC mode at UT210E. This method allows to reduce residual indications in the mode of measurement of a direct current (DC 2A Dotless, 2A,20A,100A) without the need for EEPROM correction without the programmator. Thanks of kDnZP from a Russian-speaking forum! The clamp is used for all current measurements and for NCV. There is a red led at the bottom of the clamp to show when voltage is detected with the NCV function (Buzzer will also sound). As you can see, the two meters match up well, better than I expected! I tested voltage and resistance too against some precision references and precision resistors. It read 0.4% high on average in voltage mode (worst: 0.47% or 5 counts) and was generally bang on in resistance mode (worst: 0.2% or 2 counts.) The big IC (DM1106EN) is the main multimeter chip and the frontend for the clamp is mounted close to it (U4:OPA4330 Quad OpAmp).