An actual properly rated multimeter should not present a hazard to the user no matter what you do with it, as long as you are connecting it to a source which is within the meter's ratings (both for voltage and short-circuit current capacity). This is accomplished by a combination of extremely conservatively-rated components, PTC fuses, high-interrupting-capacity traditional fuses, adequate leadwire insulation and wire gauge, proper creepage and clearance distances inside the meter, etc. On the ohms scale, the meter should not be permanently damaged even if connected to the mains or a battery. Even on the current measurement ranges, the meter should not fail in a dangerous way if connected to the mains or a battery. The high-interrupting-capacity fuse should blow before any uncontained failure. Sean On Mon, Sep 3, 2012 at 5:31 AM, William "Chops" Westfield wrote: > > On Sep 3, 2012, at 1:54 AM, Picbits Sales wrote: > >> "He was trying to measure voltage when it was set to the current range" >> >> Connect that meter on its 10A range across a car battery and you'll see = a >> similar meltdown. > > There was discussion on EEVBLOG about some of the technical details. > Apparently the big problem is that these meters contain a little bitty 0.= 5A 250V fuse (says so on the back) that is not adequate for protecting you = from stupid mistakes. (even though the top voltage range is supposedly 1000= V.) Accidentally short a 480V high-current AC power main, and the whole me= ter/fuse/leads assembly turns into a big "exploding wire with arcing" demon= stration. > > A "real" meter apparently contains special safety fuses rated for higher = voltages, spec'ed to interrupt very high currents, and costing more than th= e whole HF meter. > > http://www.amazon.com/Fluke-203403-Digital-Multimeter-Replacement/dp/B007= IV5KPE/ > > I don't know about 110V. Seems like it should be barely OK. (anyone hav= e examples of spectacular failures in 110V circuits?) > > BillW > > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .