Measruement range for Amps for portable Multimeters

[alm]

The shunt for the uA range will have a much larger value than the shunt for the 10 A range, so the damage from putting it across your circuit will be much less. Switch design is also much easier. This is why it's very common for the mA and uA range to share the same input socket, but sharing mA and A is not so common.

[Slothie]

Don't be afraid of electricity! If you're working on voltages of 50v or less (as most of us are most of the time) its virtually impossible to get a shock or kill yourself (I'm told licking the top of a PP3 is painful, but I've never been stupid enough to try it!). I guess if you impaled yourself with some electrodes near the heart and attached 50v to it you might kill yourself, but if you're doing that then you have more problems than the risk of electric shock!

You can get burns if your skin is too near when you short out a high current source, so its worth being careful with high power battery packs (NiCd, LiPo etc) but if you are reasonably cautious then you've really nothing to worry about, aside from damaging expensive equipment.

High voltages and Mains are a different matter, and you should assume that they are "live" or capacitors fully charged until you have proven positively to yourself they are not.

If you're using a multimeter with insulated probes and you know what you are trying to measure then you are perfectly safe. I've done a LOT of mains work (250v and 400v AC) and have never received a shock using a multimeter on live wiring because I take my time and make sure I use good quality probes and wear gloves when reaching through chassis to get to the point I'm measuring!

[NiHaoMike]

Up to a few A would be good for direct measurement. Above that, insertion resistance can cause significant measurement errors in low voltage circuits and a Hall effect current probe would be more suitable.

[Hans Gebert]

@rr100: the specs of the metrix mtx say that I starts measuring volts by 0,1V..and amps by 1mA....Thats pretty shitty isn't it? Don't u have problems with these ranges?

[rsjsouza]

I'm told licking the top of a PP3 is painful

Try licking the top of a 9V battery. It is shocking. I did it when I was a child (6 or 7) convinced by my older cousins this would only cause a tickle... 

[G7PSK]

I'm told licking the top of a PP3 is painful

Try licking the top of a 9V battery. It is shocking. I did it when I was a child (6 or 7) convinced by my older cousins this would only cause a tickle... 

I would not describe the feeling of 9 volts on the tongue as painful, certainly not comfortable and most certainly distasteful, leaves a nasty acidic come metallic taste on the tongue for a short while, not some thing I would do for kicks but I often check PP3 batteries this way if I think that they may be bad and I don,t have meter to hand, I can tell from the size of the buzz approximately what state the battery is in.

[rsjsouza]

I would not describe the feeling of 9 volts on the tongue as painful (...)

You are probably right on your description of the sensation... At six years old, I wasn't so sophisticated or versed in words to describe it...

[rr100]

@rr100: the specs of the metrix mtx say that I starts measuring volts by 0,1V..and amps by 1mA....Thats pretty shitty isn't it? Don't u have problems with these ranges?

You're reading it wrong or you have really unreasonable expectations. The lowest ranges are 0.1V and 1mA and being 100 000 counts it means it has 1uV and 10nA resolution. That is 100 times better on V and 10 times better on A than Fluke 83V/87V. That is not to say it's 100 times better than the Fluke. In particular the contrast is shockingly bad, I was thinking it's my unit (it's a second hand) but from youtube it looks bad in some cases so it might be a general problem (for example at around 15:20).

But in any case the autoranging over whole V and A domain is really nice.

[nanofrog]

Whether or not a uA range is needed would depend on what you're doing IMHO. Personally, I like having it, even if I don't need it very often.

As per greater than 1A (10A based on the poll selections), I see this as necessary, as even a wall wort can exceed 1A current output (amongst other examples others have posted).

[Hans Gebert]

@rr100: means there is no problem in measuring flame sensing diodes?

Fluke 17X series starts with 5mA range if I read the specs correctly..6000 Counts...means 5uA would be shown as : 0,005mA ?

?

Not really useful for flame sensing.. or am I totally wrong? (It's late..-.-)

[rr100]

The numbers sound right but I've no idea what the flame sensing diodes do, if they need some nA scale, if you need to capture some singular events, etc.

[rsjsouza]

Fluke 17X series starts with 5mA range if I read the specs correctly..6000 Counts...means 5uA would be shown as : 0,005mA ?

According to its manual, the 17x series (175, 177, 179) has 6000 counts and the lowest range is 60mA - which gives a resolution of 10uA...