Looking specific ''duspol''

[fezder]

Hey all, hopefully someone could help out with simple matter. I've been looking ''duspol'' tester as normal multimeter is pretty clumsy and somewhat unreliable to use when checking mains live cord etc, you get the picture what i mean. By duspol, i mean that meter that has two leads, along with meter itself, like fluke T90. But the model i'm looking, can detect live with BOTH ends of tester. The fluke we use in school, teacher admitted it is that way bad, as when you plug it in socket, wrong way, ''sense'' lead to neutral, and take out the sense-lead, it shows that there is no live-cord in there, but is there, just at neutral leads place, which doesn't know it is live. Sorry if this was complicated, it's just somewhat hard to describe it. And models i looked from fluke and ambrode dont seem to have this feature in them, at least manual doesnt say it. Simply said, neutral/com lead could also detect live-wire, not only sense-wire

Thanks in advance! and sorry if this is wrong place for this topic, i trust in your judgement....

 

[alec_t]

Use a neon screwdriver?

 

[MikeMl]

Any meter is a two terminal device. It has a high, but finite, input impedance between the two input terminals. It requires a small, but finite, current through the meter to register as a reading. The meter must be connected between Line and Neutral (two separate connections) to read the Line to Neutral voltage.

In the US, Neutral is connected to earth ground. If you take a high impedance AC voltmeter, and lay one of the leads on the earth (no direct connection, just capacitive coupling through the wire insulation), and connect the other lead to Line voltage (120V 60Hz in the US), the meter will read a few Vac, indicating the presense of Line potential. If you connect the other lead to Neutral potential (0V), then the meter will read much lower...

It is all about the capacitance of the floating lead to the earth...

btw- the neon indicator probe works the same way. So does the Duspol tester. Since all of these are AC detectors, the leads can be swapped, and the readings will remain the same...

 

[fezder]

hmm, didn't thought about using neon screwdriver. But isn't there this issue with ''ghost'' voltage?

 

[KeepItSimpleStupid]

I'm clueless as to what your looking for.

Would this **broken link removed** help?

I actually have one of the models.

What's not shown in the pic is an IEC power inlet connector to which a 12" AC plug is usually attached too. Other tests require the use of clip leads. See the manual for details.

It was recently invaluable in finding a high Z ground.

 

[fezder]

hey keepitsimplestupid. That meter-range looks interesting, but i don't think that's what i'm after. Looks good quality thought, gotta keep that in mind too. But, let me re-clarify:
Like an example with this meter which we use at school and in different workyards:

https://juhansahko.net/verkkokauppa/images/fluket100_58051_1206_efa.jpg

it can detect live voltage with the red/right hand probe, but not with neutral/black. Like in situation where socket is wrongly assmbled, where neutral is at right hand side of socket. So we measure it right handed, it shows no mains is present. of course we measure it also wrong way too, just to make sure. Any help?

 

[RODALCO]

Good duspols are the orange or red ones from Bennings.
They have an Neon indicator and a plunger which imposes a burden on the circuit under test.
Load is about 100mA.
A DMM can give false readings as it is to sensitve. For example an open switch may read a stray voltage of about 50 Volts on a DMM. A duspol will give a zero reading.
Bear in mind that readings under 50 Volts are not accurate as the Neon won't glow and the plunger hardly moves.

 

[fezder]

i've heard about benning as a mark, seems good quality brand?
as for DMM's accuracy, i noticed that, even 100 volts of stray voltage, i was in 1'st grade when i first encountered this ghost voltage and i was like ''what the hell?...''
luckily, 50v is considered ''safe'' but hey, there dwells huge current in car battery and that's only 12v....

Do you know any model from benning which has this neon bulb, and is it in prodution/fulfill current conforms in the safety? no worries, i won't touch over 3-phase voltages (not literally touch of course!)

 

[RODALCO]

Benning is a German manufacturer.
I put up a photo later today.
I also use an other duspol with LED's which works very well too.
Think it is an APPA

 

[RODALCO]

Just looked on the Benning page. All new duspols appear to be electronic ones.

 

[fezder]

yeah, i noticed same thing, crap, sort of. well there should be the duspol i'm looking for, amprobe (or meterman, aren't they the same?) makes it, at least that was said to me. But, to think about it, i dont need that specific, if i just measure both ways, which is the way we are taught, it should be safe. after all, safe is the thing with mains voltage...

 

[RODALCO]

I took some photo's of my Appa and Bennings Duspols.

It appears that the older style Bennings duspol is not available anymore. Everything has gone to LED or LCD indication with or without Voltmeter display.

On the Bennings Duspol the Neon glows over 50 - 60 Volts AC. When the button is pushed the plunger pulls in, imposes a burden and gives a course voltage indication.

The Appa is self explanatory. To be hones I use the Appa most of the time.

 

[fezder]

okay, thanks for info. never heard of appa before