Multimeter

[Dave Plowman (News)]

IMHO it would be impossible/too expensive to provide a resetable breaker that acts fast enough to protect solid state devices. Hence the very expensive fuses - I've no idea how they work.

[whisky-dave]

No. You're probbaly thinking of cutouts which are slow acting. =20

well sort of, most have had perhaps 10 years at school, most should have do= ne physics to GSCE or A-Level before they even come to univ.

No. the teachers here are lecturers their job appears to be pointing at a w= hiteboard controlled from their labtop then telling them to printout a 100 = power point slides.

Part of the idea of doing a practical lab is to learn stuff by experiment. You;d have thought parent could teach their kids how to sit on stalls/chair= s quietly and attentively while the teacher or lecturer speaks too. =20

[Dave Plowman (News)]

maybe the fluke branded ones are more expensive.

My Maplin meter uses standard 20mm fast blow. But whether this protects the meter as well as the Fluke type from a massive overload, who knows?

[whisky-dave]

True, I've had a total of 89, 318 & 328 over the last few years only 3 have gone faulty so that's not too bad, not sure we'd have done better buying 90 odd flukes we certainly found it easier to replace the cheap meters.

Looking at fuses

each

each

Not sure how much a geniuine fluke fuse would cost maybe adda zero on the end

[Mike Lane]

Ian Jackson wrote on Aug 28, 2012:

Err - no, I don't actually find puns amusing in the slightest. Just poor proof-reading.

[alan]

Not if it's brewed by Greene King :)

[geoff]

In message , Mike Tomlinson writes

Well, actually, IPA is the only other alcohol that is not poisonous

(as opposed to Tetleys, which is)

[polygonum]

Not sure I'd go along with that:

I do agree that in many IPA poisonings there are complicating factor= s =

- such as another alcohol being present.

[Andy Wade]

Standard 20 mm fuses are only rated at 250 V with a breaking capacity of

35 A (glass type) or 1.5 kA for the ceramic HBC types.

The fuses fitted in multimeters with Cat III/IV safety ratings have much higher voltage and breaking capacities. Taking the Fluke 77-4 meter as an example, the 440 mA fuse is rated to break 10 kA at 1 kV and the 11 A fuse for the highest current range will handle 20 kA at 1 kV.

If you use your multimeter in your consumer unit or with a big battery bank, or anywhere else where high prospective short-circuit fault levels are present, the cost of the correct fuses isn't much to pay to avoid any risk of the test leads suddenly vapourising in front of your face.

[John Rumm]

Indeed. Regular readers may recall that report from the shopping mall where a meter with inappropriate protection was used on a distribution board... a mains transient caused a breakdown in the DVM which triggered a major arc flash event - killing the operator and a bystander IIRC.

[whisky-dave]

So not really essential for a DIYer

Maybe that's the differnce bewtween pro and hobby meters. I don;t remmebr the above incident.

[John Rumm]

I think this was the one:

[Md Rashed Ali]

Hi,

It's great that you want to learn something new. I hope this adds some value to you. It's a guide for "Choosing the Best Multimeter."

[The Other John]

He has probably chosen one by now, since the original post was over 6 years ago! You even quoted the date in your reply. Try reading what you are posting before hitting the 'send' button.

[tabbypurr]

It also is written by someone who could do with learning more about the subject

NT

[Brian Gaff]

2012, are we sure he is still alive? If the originator did not really understand a multimeter, he might have been electrocuted in the intervening years! :-) Brian

[Andy Burns]

I should hope so, I think he was our youngest poster ...

[samchunk]

Does that make him a poster child ?

[John Rumm]

but I am sure he thought it was just a convenient place to spam his website details where he hopes it might get found in searches.

[Dave Plowman (News)]

'The common features of a digital multimeter are frequency, conductance, resistance, inductance, continuity.'

But not voltage or current? Very odd common DVM, I'd say.