Uni-T UT70B DMM

This UT70B multimeter is made by Chinese manufacturer Uni-Trend Group Ltd (Uni-T).  Their products occupy positions in the low- to medium-cost part of the market, and enjoy a decent reputation amongst hobbyists.  Some Uni-T models are rebranded as Tenma and Voltcraft.

This unit arrives in a non-working state, but is simple to repair.

9 Responses to Uni-T UT70B DMM

  1. Harvey says:

    Not a bad looking multimeter and for general usage its ideal, nicely made pcb and adc i.c thats known to be reasonable 🙂

    I have thought about the UT61E a few times, but cant convince myself i need a new multimeter lol.

    Smashing writeup as allways 🙂

  2. M. Qasim Saharan says:

    Can I ask? How crazy its mV range acts?
    I have exactly the same meter. Its mV range seems very very much sesitive. For example, when I turn it on, it starts with an overload ‘OL’ beep. If I touch it or move while holding it in my hand or, say, bring it close to my computer it starts jumping around swiftly and not actually showing any proper reading. And when the probes are attached it becomes even more sensitive, almost crazy.
    Otherwise, the meter works fine.
    I must say, with no probes attached, it do starts settling down aftre some time. But with probes attached, it stays crazy.
    Can you comment on this behaviour, please.

    • modemhead says:

      I’m out-of-town right at the moment so I can’t check, but I do seem to recall that the mV range was very sensitive and “jumpy” which really is not too unusual for any multimeter, especially ones that have higher than the usual 10 Meg input impedance on the mV range. If you short the probes however, it should read zero or very close.

  3. Phil Anderson says:

    Great review. I lost one of the contact springs for the selector wheel. Do you know of a parts source for those? Almost new meter and now doesn’t work. Unable to find one for parts.
    Thanks

    • modemhead says:

      I have no idea where to find something like that for sale. I did fix a cheap-O meter recently that was missing a contact spring just like that. I cut a tiny rectangular piece from some thin brass sheet metal, bent it into a shallow “V”, then cut the slot with a thin cut-off wheel on a rotary tool. It does work, but I don’t know how low it will last, since the brass isn’t as “springy” as the original.

  4. Uwe says:

    Hello Mr. Modemhead,
    In my UT70B, 2 surface mount resistors have burned out, R31 and R32.
    I was wondering if you could tell me their values so I can replace them.
    Thank you for your help.

    • modemhead says:

      R31 & R32 are 9.00 ohm through-hole resistors on this unit. Soldered in parallel for a result of 4.50 ohms. The pair function as the mA range current shunt.

      • Uwe says:

        Thank you for your reply and help. I will first try to fix those 2 resistors. My problem is not the mA range but the DMM does not switch on anymore. So far I could only identify those 2 burned resistors.

  5. Alma says:

    My friend i hace this same unit sold as baw brand. Its showing overloaded OL issue. I should check for burnt resistors? Thanks from Argentina

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