EEVblog #84 - High Energy Multimeter Destruction

Let's destroy some multimeters and shoot some metal with Doug's high energy 4KV capacitor discharge unit.

[ПетяТабуреткин-вт]

Top-3 strongest materials on Earth:
3. Steel
2. Titanum
1. Decimal point

[TheAxemarauder]

Just for giggles, I calculated the height the aluminum block reached based on its airtime.  It was airborne for ~3.3 seconds so it went ~13m high.

[Nivicoman]

The maintainance man at my work attempted to check mains voltage into the building. He was inadvertantly on the primary side of the transformer (13.2 Kv). Needless to say his Fluke 87 multimeter left nothing but the handholds of the leads. It's a wonder he wasn't hurt with the arc flash explosion of the meter.

[bitrot]

I had to console my poor old Fluke 77 meter that was sitting next to me on the table while I watched this. At least his brother performed admirably in your test.

[EEVblog]

@FoamPackingPeanuts
You can see the dials, they were all set for DC volts. So the current range fuses did not play a part.

[syncmastern]

you can't fry an old fluke 70, thats like sticking your granddads fingers in a socket. you evil man, i still have my fluke 73 and it has served me faithfully for over 20 years, it never let me down and I still use it.

[EvioneElectronics]

The CAT rating on meters is very important when working with high energy circuits. Simple reason is transients and such. Nothing worse than a flash accident due to your meter being sub standard. My high energy working meters are no less than CAT III 600v. My normal everyday bench and field meters are CAT IV 1000v and this is purely for safety reasons. Good movie.

[TheRedneckAtheist]

The wiring job on that huge power supply was just awesome!

[windcalmer]

One thing, Having spent a great deal of time dealing with airflow, and heat dissipation. If you setup your cooling fans to pull, and place them at the top you should see an ENORMOUS increase in cooling. Just throwing that out there, only because I know most folks settle for the cooling them can have, rather than trying to perfect it. Hope it helps you out at some point. GREAT JOB btw!!!

[sanity]

That was fun but I wouldn't say that El Cheapo meters are bad because they couldn't handle 4Kv. I seriously doubt that the folks that buy $20 meters are going to even have access to 4Kv.
But Hey I guess I will drop $1500 on a Gossen just in case I want to measure across a 4Kv line. Yea right

[EEVblog]

@ubuntututorials
Yes, such low cost meters are good enough for general use. And you are wise not to use it on the mains or other high energy gear.

[eurokid]

The Fluke 70 series was still going through the segment check after four shocks. That's proof of the safety and quality of Fluke multimeters.

[RollerBGM]

6:15, I had the exact same meter before I bit the bullet for a fluke.

It disturbs me that it was the only one that blew up literally. Close shave, but of course I wouldn't have stuck it into the mains or anything.

[EvioneElectronics]

Some Brymen model meters are CAT IV to 1000v on their voltage/ohms inputs. Obviously not on the current inputs.

[dzarren]

Poor African children could have eaten those multimeters.

[arabquarter]

You can now replace a lot of those glass fuses with the correct SIBA FF Ceramic Fuses that will handle up to 600 Volts in the 10 Amps if you only have a 6 mm x 30 mm fuse and 1000 Volts in the 500 ma using the same 6 mm x 30 mm fuse. Klein Tools 69033 FUSE 5 mm x 20 mm 500MA 600V, this is a ceramic fuse with more than likely sand filled inside. This will help get your meter closer to being the proper cat II and proper cat III rating without having to pay a lot.

[coetzeer]

The last Fluke also blew the top of component U12 above the selector switch. You can see the die through the hole. Nasty.

[freespuddy]

My old Fluke stopped working when it was accidentally exposed to about 20KV in an old style TV. However, I replaced one IC and it works like new except the AC voltage reads about 0.4 volts high.

[phaedra]

t=6:45 Looks like a green PTC just below the buzzer. Not on the voltage side or too slow? Blew apart because no screws? No screw remnant or break in the posts, so seems like unfair test.

[TheFootbaldd]

I had an instructor mention my use of zipties in my project as if he didn't know better. Nice setup there. I need some more MOTs.