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UNI-T UT33B - "Cheap / Dear" - multimeter with backlight and HOLD func

CMS 7197 52
This content has been translated » The original version can be found here
  • #31
    Janusz_kk
    Level 29  
    E8600 wrote:
    For example, a new 1.5 V AAA battery can have a short-circuit current of 3-5 A, while if the short-circuit current drops to 0.5 A and the voltage drops below 1 V, the battery is dead.

    This way of treating the batteries destroys them, to check the drop for AA 100mA is enough, the idle voltage and drop are tested
    under load, it can be concluded from this about the health of the battery, best compared with new ones.
  • #32
    CMS
    Administrator of HydePark
    gruby1 wrote:
    You gave the table in the first post to my friend from the UT210x model.


    Thanks, I've already corrected. This is what happens when you write about several multimeters at the same time.
    You get 100 points.
  • #33
    timo66
    Level 23  
    BANANvanDYK wrote:
    timo66 napisał: wrote:

    I dare to notice that the meter does not even have a fuse in the 10A range !!!


    It has a protection in the form of a path at the input terminal that just gets hot. I think it is the same in the presented UT33B. I know because someone burned him to me and I had to cheat.


    Kraniec_Internetów wrote:
    Most cheap meters don't have it. But it's not a problem. In case of trouble, the metal plate that goes from the connector to the solder pad usually burns, and it can be easily repaired or strengthened.


    One-time protection is not a protection, this is why this place is wired and repaired and I don't believe that someone is soldering a fuse in this place. I know that the next thing that will get hot are the measurement cables, but if they come from other equipment that is 20A strong, the meter will go up in smoke !! Therefore, I will continue to insist on the lack of security.
  • #34
    tomybb
    Level 26  
    As for the "automatic" version of this meter, I have no objections. Although I do not use it every day, it drives in the car and sometimes it comes in handy, from its great advantages: a fast-acting machine and a buzzer without any delays (which is very important to me). If you want, I can also review it.
  • #35
    tytka
    Level 19  
    CMS wrote:
    Tomorrow I will do additional tests and present the results. However, regardless of the results, I still find the "battery test" feature quite redundant.


    Basically, I understand your opinion, but personally I would aim for the opinion - much less useful. It even seems to me that the manufacturer understands it, because he has equipped this function only in one of the four versions of this model; so that the potential buyer can decide for himself what is better for him.

    I am waiting for the official results of additional tests, will they be confirmed with my unofficial ones. I allowed myself to visit a friend of the owner of such a meter model. It turned out unofficially that the battery tester, when measuring the cell used, definitely indicates something other than a voltmeter. The indications even vary depending on the set range of the battery tester (for example 1.08V for the 1.5V range; 1.21V for the 9V range; and 1.19V for the 12V range). It quickly turns out that the current consumption from the battery (used AA cell) when measuring in the 1.5V range is about 21.5mA, in the 9V range it is about 0.6mA, and when set to 12V it is about 4.5mA. But these are the results achieved "on my knees". It turns out that the manufacturer had a concept here, the battery loads during the measurement, depending on their capacity.

    And the cables / measuring probes on this meter are actually of poor quality.
  • #36
    CMS
    Administrator of HydePark
    Well, you learn all your life. As I said, I had not dealt with a battery test in a multimeter before and for this the previous measurement with a fully charged 1.2V battery was incorrect.
    It turns out to say that, as you thought, the meter introduces some load on the battery test range. I am enclosing new tests on used batteries.

    UNI-T UT33B - "Cheap / Dear" - multimeter with backlight and HOLD func UNI-T UT33B - "Cheap / Dear" - multimeter with backlight and HOLD func
    12V battery

    UNI-T UT33B - "Cheap / Dear" - multimeter with backlight and HOLD func UNI-T UT33B - "Cheap / Dear" - multimeter with backlight and HOLD func
    9V battery

    UNI-T UT33B - "Cheap / Dear" - multimeter with backlight and HOLD func UNI-T UT33B - "Cheap / Dear" - multimeter with backlight and HOLD func
    1.5V battery

    tytka wrote:
    When measuring in the 1.5V range, it is about 21.5mA


    Well, how he shot the face :D .

    As you can see in the photos above, in the case of used batteries, the measurement result in the 20V range is different than in the range dedicated to a specific battery.
    However, I still feel that this feature is unnecessary. The more that the battery can be checked without any instruments, a piece of flat hard surface is enough ...
    Do you know this trick? Although I'm not sure if it will work with a 12V battery, it will not work for the bank at 9V. In contrast, other cylindrical cells (including 18650) can be checked with this trick.

    100 points, for the first person to guess what I mean.
  • #37
    kkkamil
    Level 13  
    I think it's a very good piece of equipment for the price. Of course, it all depends on your needs. I have a version with a "pipawka" and some advantages in my opinion:
    - rubberized,
    - mechanically switched backlight,
    - perfect size for me,
    - relatively indestructible, and in the event of breakage, no cost.


    As for accuracy, it is of secondary importance to me. In the field, in unfavorable conditions, it is simply a "firecracker".
    And if someone needs a meter with 4 decimal places, he should probably spend more than PLN 30 ;-)

    Best regards. Kamil
  • #38
    User removed account
    Level 1  
  • #39
    E8600
    Level 39  
    CMS wrote:
    Do you know this trick? Although I'm not sure if it will work with a 12V battery, it will not work for the bank at 9V. In contrast, other cylindrical cells (including 18650) can be checked with this trick.

    100 points, for the first person to guess what I mean.

    Well, I think that working or not working do not want to turn / twist on a flat surface?
  • #40
    CMS
    Administrator of HydePark
    After taking into account the results of the new tests (current in the mA range and battery test), I find that apart from the lack of a beep, there is nothing to complain about. However, I cannot imagine how the manufacturer came up with the idea of neutering the meter from its basic function. Well, no one is infallible, but as you can see with your help, we managed to turn the opinions about the meter by 180 °, maybe 150 °, because this beep ... :)
  • #41
    User removed account
    Level 1  
  • #42
    CMS
    Administrator of HydePark
    Kraniec_Internetów wrote:
    If you drop a cylindrical battery from a low height so that it falls to the ground with one pole, depending on whether it falls and remains constant, whether it bounces off the table, you can determine whether it is operational or not.


    I transferred points.

    Another 100 for the person to say why is this happening?

    Allle wrote, before I answered the first post, three more appeared
  • #43
    User removed account
    Level 1  
  • #44
    CMS
    Administrator of HydePark
    I meant "overall electrolyte density" in batteries / accumulators, but after all, the answer is correct.
    I was counting on the answer "own", but you have shown your intention and another 100 points will go to your account.

    Added after 1 [minutes]:

    Okay, I'm done with these mini competitions, because then I will run out of points for some nice gadget from the store :) .

    Added after 36 [minutes]:

    I added the results of the "new" current measurements and the battery test to the first post.
  • #45
    tytka
    Level 19  
    Well, now we have a complete and reliable test of this gauge. As it should be presented.
    As you can see, it has some drawbacks, but taking into account both the price and its capabilities, it is not a bad choice for an undemanding user.
    Anyway, now we also know that you can choose a more suitable version of this model with slightly different possibilities. And even aim for the one that offers a bit of luxury for a slightly higher price :)
  • #46
    Stanley_P
    Level 27  
    tytka wrote:
    Well, now we have a complete and reliable test of this gauge. As it should be presented.

    As they say - "I would not like to pick on, but ..." However, since the battery load test was carried out, I counted - as a reference - on measuring the current first on new, fresh cells. Or even from the power supply, in the absence of any. And then, possibly, a visual comparison of how it looks on the used ones. For example, the result of 7mA and 2.18V on a used 12-volt battery does not tell me much (apart from the fact that it is completely used up, which can be seen without a special tester already when measuring the range of an "ordinary" voltmeter: 7.79V).
    The second thing: the presentation and comparison of the current consumption when measuring with a voltmeter, using the device used here (clamp ammeter with a range of 2000mA and the accuracy of the last digit of 1mA) may be misleading and actually makes no sense in this case. According to specification, the UNI-Ta input impedance on all DC ranges is 10M?. So for a fresh 12V battery, the current consumption would be 1.2 uA - well below the capabilities of this (mile) ammeter. For lower voltages even less, respectively. And in the photos we see 1-2mA (although this device should show 0, at least theoretically), I suppose due to inaccurate zeroing or "this type has it".
  • #47
    CMS
    Administrator of HydePark
    The meter will appear in the shop, so you will have the opportunity to do additional tests and submit it on the forum, for example in this topic.
  • #48
    Stanley_P
    Level 27  
    @CMS, I get a bit of a nuisance, I am aware that the electrode tests - otherwise very valuable - are made by enthusiasts, in their spare time, and not with laboratory equipment and not in laboratory conditions. However, if possible, let's make sure they are correct. If I see that the measured voltage is 7.79V, and the current consumed by the voltmeter is 2mA (!), Then without further reflection I can assume that the input resistance is 3895? (let's say about 4k? ;) . Which in this case is obvious nonsense, or the instrument is damaged ;-)
    My guess is that you wanted to show here that when measuring batteries on voltmeter ranges, the current consumption is practically "none", "zero". However, in this case the 1-2mA indication is a lot, since the actual consumption is a thousand times smaller, practically negligible here.
    I propose to cut the ammeter from the photos with the graphic program, where the batteries were measured with a voltmeter and at least it will be fine ;-)
  • #49
    BANANvanDYK
    Level 39  
    Out of curiosity, I checked the behavior of the meter depending on the battery voltage, I was mainly interested in the phenomenon of over-reading.
    In my copy, the threshold voltage of the battery discharge indicator is 6.9V. Below 6.2V the measurement result started to increase. Well, I went as low as possible with the power supply. Exceeding the range on 20V, the dot has already disappeared and the display shows twice the result:
    UNI-T UT33B - "Cheap / Dear" - multimeter with backlight and HOLD func
    I did the same with the UT33A. In this case, the meter only slightly lowers - in the case of this battery, during the test the indication dropped to a maximum of 12V. Only the meter will turn off at 1.5V, but it will only turn on at 1.8V. The battery indicator threshold is 2.3V. I just forgot to note at what voltage the lowering of indications begins.
  • #50
    Uli939
    Level 2  
    UNI-T UT33B - "Cheap / Dear" - multimeter with backlight and HOLD func

    Scouring the network for good pictures / schematic for the above-mentioned multimeter, I came across this topic. I need to read the bar code of the r34 resistor, unfortunately I have a problem with it even after enlarging and brightening the photos from the first post. Could someone who has this multimeter check the colors of this resistor?
  • #51
    CMS
    Administrator of HydePark
    It is red, orange or yellow and two black. 235 ? comes out of the measurement :) that is, in the middle between yellow and orange :) .
  • #52
    Uli939
    Level 2  
    It seems to me that there is still green in front of black and gold at the end?
  • #53
    CMS
    Administrator of HydePark
    I say what I see after undressing, seeing and measuring. It is golden, but it is tolerance.