Author Topic: Help! Total beginner- Just recieved my new UNI-T multimeter and I've killed it  (Read 22467 times)

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Offline Zero999

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Skin effect refers to electron flow.  Microwave heating in a non-conducting material has nothing to do with electron flow.
Yes, indeed non conductive fats can be heated in a microwave.

Nice links by the way, I'll remember next time I have this discussion. :D

I used to have a 24V AC/DC power supply i made from salvaged parts from a TV, at 24VDC I could feel nothing, at 24VAC I could feel a tingle in my fingers
I'm not surprised, the IEE regulations state that in dry areas, all voltages above 25VAC need to be insulated but DC voltages up to 60VDC don't need to be insulated.
 

Offline Time

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Skin effect refers to electron flow.  Microwave heating in a non-conducting material has nothing to do with electron flow.
Yes, indeed non conductive fats can be heated in a microwave.

Nice links by the way, I'll remember next time I have this discussion. :D


Yep.  They can be heated because of their hydroxyl groups (OH attached to some other organic compound).  I was going to make this point to further my OH bond claim but I decided not to bring organic chem to a physics discussion on an electrical engineering forum.  Its just a coincidence that the link I posted down below mentions it directly in a footnote.
-Time
 

Offline Kiriakos-GR

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Handbook of psychophysiology  !!!

 ;D  ;D  ;D    oh my what the people are reading this days ...

Yes talking for Mars , with out to have even get there , its an easy task ..
 

Offline Hypernova

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Man this thread takes me back to something incredibly retarded I did when I was a teen with MORE POWER stamped all over me brain.

Cliffs:

1) Boy finds broken microwave  :D
2) Boy extracts the transformer out of said microwave.  ;D
3) Boy hooks up low side to the mains.  ???
4) Boy tries to measure the voltage on the other end.  :o

It's a damn miracle how I didn't die right then and there that day. Only my multimeter blew. Ironically it was an award from Dick Smith from my high school electronic class for something I built.
 

Offline Kiriakos-GR

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Well,  from my prospective , 
by trying  to get-rid all "your own"  responsibility ( nothing personal)  about safety , on to an instrument that was build to be used by people with common experience about such matters ..   

Makes my brain to explode .. simple as that .  :) 
 

Offline david77

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Just wanted to say something about RCD's. They do not switch off slower at a smaller leakage current!
A 30mA RCD kicks in at about 25-30mA leakage, depending on make.
In most EU countries a 30mA RCD is only required in new installations, there are still millions of homes
without RCD protection. I love the RCD in my workshop, it has saved me from some nasty bites.
You can get them with 10mA IdeltaN, too, if you want to play it safe. Some electricians I know recommend
a dedicated 10mA RCD for bathrooms.

The problem is "normal" people don't understand what a RCD does, and that it is different to fuses or MCB's.
Add to that the cost of 40-50 EUR and the cost of installation and you can imagine how many people have
one installed...
 

Offline Fraser

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A little off the topic but I thought I'd chuck it into the conversation.....

Just like the saying regarding ladders.... it's not the falling that hurts it's the stopping when you hit the ground  ;D

People have been seriously injured and even killed when they have been testing a non lethal voltage/current combination whilst working at height... they get a good shock that startles them, they lose balance and fall.... the fall distance and what they hit influences the severity of the incident  :(

Another accident that I was told of whilst at Maritime college was an when a ships RO dropping a high vacuum RADAR CRT after accidentally touching the Anode feed hole....  Implosion followed along with plenty of flying shards of glass.... nasty ! No serious injury but still not a great situation to find yourself in.

The moral of the tale..... a lethal accident is not always caused by a lethal stimulus.
« Last Edit: October 24, 2010, 06:04:09 pm by Aurora »
 

Offline Mechatrommer

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The moral of the tale..... a lethal accident is not always caused by a lethal stimulus.
good point! but still, the stimulus is the one who started it, no matter how "unlethal" it is ;)
ps: a woman will drop the glass when a mouse just passing by.
« Last Edit: October 24, 2010, 01:25:35 pm by shafri »
if something can select, how cant it be intelligent? if something is intelligent, how cant it exist?
 

Offline PetrosA

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Looking over some statistics for the US, at the start of the 20th century, 50% of electricians were killed by electric shocks at work. Today, the main cause of death is falling off of ladders, and a lot fewer are dying at work.
I miss my home I miss my porch, porch
 

Offline Fraser

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I'm fortunate to be qualified to work on many types of electronic and mechanical equipment but I know when to call in a specialist .... I hate working atop ladders and leave my TV aerial installations and roof repairs to those who do it as a daily job. I have worked on ships masthead Radar scanners and HF/VHF aerials but HSE provides plenty of anti fall countermeasures in those scenarios. Such are not normally present when doing 'domestic' DIY etc. A very wise aerial rigger once told me that I would fall because of holding on too tight ! He was right, you need to be relaxed and disciplined when working atop 100 foot aerial masts that are swaying in the wind :o

You still hear of people being paralysed or worse, killed, whilst trying to save a few pounds doing DIY aerial erection on their house roof. I know my limits and GBP100 or so is cheap compared to serious injury or worse.
 

Offline PetrosA

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I miss my home I miss my porch, porch
 

Offline Mechatrommer

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so the keyword is still valid i think... "Safety First"
if something can select, how cant it be intelligent? if something is intelligent, how cant it exist?
 

Offline Kiriakos-GR

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so the keyword is still valid i think... "Safety First"

Yes for the DMM , that's why I got the 28II   ;D   ;D   ;D
if we fall together, it will survive and tell what had happened ..    :D




.
« Last Edit: October 24, 2010, 11:49:00 pm by Kiriakos-GR »
 

Offline Fraser

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That video made me feel quite queezy !

I hope they get paid well and I wouldn't want to be their life insurer  :D

The High Steel workers who assemble the girders for skyscrapers are another group of gentlemen for whom I have the greatest of respect. They also find it easier to free climb and one told me that he considered a safety strap an added danger as it got in the way !

Great video. thanks
« Last Edit: October 24, 2010, 04:56:32 pm by Aurora »
 

Offline Mechatrommer

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That video made me feel quite queezy !
they should wear parachute! for three purposes. 1) accidentally fallen 2) quick way to go down 3) having fun of parachuting.

They also find it easier to free climb and one told me that he considered a safety strap an added danger as it got in the way !
yea right, added danger! when u wear the strap and got fall down, u probably got a broken rib due to hit to the wall or something and feel the pain. without the strap, u'll just drop blacked!
if something can select, how cant it be intelligent? if something is intelligent, how cant it exist?
 

Offline saturation

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I wonder what happens if you have to go to the bathroom?    :-[

OK for the guy on top, but what for the companion guy below?  :o

That video made me feel quite queezy !

I hope they get paid well and I wouldn't want to be their life insurer  :D

The High Steel workers who assemble the girders for skyscrapers are another group of gentlemen for whom I have the greatest of respect. They also find it easier to free climb and one told me that he considered a safety strap an added danger as it got in the way !

Great video. thanks
Best Wishes,

 Saturation
 

Offline Zero999

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Make your own welding gear. :D
 

Offline Fraser

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Quote
I wonder what happens if you have to go to the bathroom? 

You take a bottle of Coke with you, drink it and then you have an empty bottle for 'other' uses  :D

The crane operators in Hong Kong used to do that but one day one of them must have forgotten as yellow rain started to fall not far from where I was standing and it was a lovely sunny day  :o
 

Offline Kiriakos-GR

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Make your own welding gear. :D

Yes and its an smart idea too , this is an hand made transformer .
« Last Edit: October 24, 2010, 11:55:07 pm by Kiriakos-GR »
 

Offline .o:0|O|0:o.

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Climbing a 1768 Ft Radio Tower!

A great view, fresh air, exercise and no room for errors. Couldn't they have some system whereby they are permanently attached the last stretch of the climb? Some sort of a strap and belt system in addition to the cord and carabiner (maybe a parachute for back-up)?
 
.o:0|O|0:o.
 

Offline Kiriakos-GR

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They get payed by five times more than the average monthly payment,
this keeps them in good shape , they do not need parachute .
 

Offline Mechatrommer

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...they do not need parachute .
sure! they just do.... or die. nothing in between.
if something can select, how cant it be intelligent? if something is intelligent, how cant it exist?
 

Offline Zero999

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What good would a parachute do?
 

Offline .o:0|O|0:o.

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It would give them a non-zero chance of survival if they fell over. Provided it didn't increase their chances of falling over. That the risk doesn't warrant a paracute is a seperate matter.

My comment about perhaps having a parachute with them was only half serious, but if you are referring to the relatively low altitude, BASE jumpers do this sort of thing for the thrill all the time and from much lower as well: http://en.wikipedia.org/wiki/BASE_jumping .

.o:0|O|0:o.
 

Offline Mechatrommer

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What good would a parachute do?
the same as safety strap does... to annoy them. well... thats a kid answer, if you want the serious answer, then.... it a safety measure in case of fell over, they can pull out the chute open so they can go down slowly and safely. and in case of the "charge suckers" fail (flower shaped on the antenna) and cannot avoid thunderstorm, then there is option for quick way down alive. they should be trained in military paratrooper first before qualifying for this kind of job, but thats is only when i become a prime minister :P. Why prime minister? because he can make any decision he want, in US its called Mr President. And sometime people dont be thankful when a rule is enforced on them. Its for the good of them, and they say its annoying. Cheers ;)
« Last Edit: October 25, 2010, 11:49:13 pm by shafri »
if something can select, how cant it be intelligent? if something is intelligent, how cant it exist?
 


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