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XL830L - A tiny, cheap Chinese multimeter. - Test / Review / Opinion.

CMS 7398 38
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  • #31
    CMS
    Administrator of HydePark
    robokop wrote:
    Gentlemen, did any of you notice how the current in the circuit affects the connection of such a multimeter? I ignore the resistance of the wires and contacts themselves ...


    vodiczka wrote:
    OK, but how the serial connection of ammeters affects the current measurement depends only on their internal resistances.


    Well, you finally start to think :) .

    I noticed you touched on the topic of connecting two identical ammeters. In that case, we'll get the wrong result anyway, but I haven't specified here again. It is known that in the review I compare the tested product with a standard (better or worse). So they will never be two identical products.
  • #32
    vodiczka
    Level 43  
    CMS wrote:
    Well, you finally start to think
    I think I started earlier :)
    CMS wrote:
    It is known that in the review I compare the tested product with a standard (better or worse).
    And for this comparison, the serial connection of ammeters was fully justified. He compared my colleague the tested meter with his own, unless I misunderstood and compared my colleague the tested meter with the indications of the power supply and added the indications of his meter to dessert. :|
  • #33
    User removed account
    User removed account  
  • #34
    vodiczka
    Level 43  
    nowyARM wrote:
    Not necessarily, for example I have a 1:10 voltage divider from 18M and 2M resistors.
    And you can't "godly" 18k and 2k :?: :D
  • #35
    User removed account
    User removed account  
  • #36
    jack63
    Level 42  
    vodiczka wrote:
    only how the serial connection of ammeters affects the current measurement depends only on their internal resistances.

    What is "Measurement Effect"?
    Is the sparrow different ???
    The question is like an abstract joke. The pythia would answer.
    Need to clarify what affects what? How does it affect and then how great is the impact.
    Serial connection of ammeters, made only for the purpose of comparing their readings, is most appropriate.
    In this way, you can calibrate one instrument against another being the reference.
    Parallel connection of ammeters is idiocy ...
    The influence of the ammeter, not on the measurement, but on the measured system is obvious and fairly easy to evaluate. We just plug in additional series resistance.
    However, the effect can be "zero" when measuring the current of a current source.
    On the other hand, the influence of the resistance of the cables, and in particular of the contact of the measuring probe with the point of the circuit, on the measured circuit is enormous, because it sometimes introduces many times greater series resistance than the shunt of the ammeter. Sometimes a device powered by an ammeter won't work properly.
  • #37
    vodiczka
    Level 43  
    jack63 wrote:
    Need to clarify what affects what? How does it affect and then how great is the impact.
    If you hadn't taken my statement out of the crowd, you wouldn't have found it abstract.
  • #38
    smyk55
    Level 23  
    CMS wrote:
    As you know, ammeters should not be connected either in parallel or in series
    Tragedy .............
    CMS wrote:
    Especially since, as you probably noticed, the measurements (due to my laziness) were made on two different resistors from the same package.
    This is how the tests are done. The test sucks ............
  • #39
    mada1950
    Level 1  
    Hello. I have such a multimeter, unfortunately the R 12 resistor is burnt. I would ask for its value. The best is dziunio400(malpa)o2.pl
    Best regards.