Case point, I was troubleshooting a switching mode PSU 3 months ago that can output 300Vdc. As I was adjusting it and reading Vout, my Fluke was going berzerk, and wouldn't hold a reading after 180Vdc. I put a CAT II oscilloscope on it and bingo, the PSU was shooting transient spikes to 1000Vdc and it was briefly going out of range of the DMM.
Case point, I was troubleshooting a switching mode PSU 3 months ago that can output 300Vdc. As I was adjusting it and reading Vout, my Fluke was going berzerk, and wouldn't hold a reading after 180Vdc. I put a CAT II oscilloscope on it and bingo, the PSU was shooting transient spikes to 1000Vdc and it was briefly going out of range of the DMM.
Well I must ask what was the model ?
If the Bar-graph...... was unable to indicate the voltage overshoot !!
If the sign of the lightning on screen .... was unable to indicate the voltage overshoot !!
This DMM looks to have issues.
Oh and btw Kiriakos, the high voltage warning light should be and stay solidly lit well below 300 volts.
I don't have a Youtube account, but I can share the original file for anyone who wishes to rehost it elsewhere. For reference, it's dated around summer '09 and marked as "rev 3".
The UEi UL certificate is definitely genuine now. It's the old meter I'm curious about: did UEi have issue with the meter they swept under the carpet or was the Fluke's meter different to the regular production model?
Oh and btw Kiriakos, the high voltage warning light should be and stay solidly lit well below 300 volts.
unless you actually have the gear to test it (and test to destruction)
Dave.
Very interesting.
I'll have to check the UEi box and meter when I get home.
It certainly struck me as very well made industrial meter, especially for the price. But of course you can't be sure it meets the overload specs unless you actually have the gear to test it (and test to destruction)
Dave.
I had , just read the manual.
<snip>
Or this ...
<huge pic>
Nothing can fool around those LEDs ..
87V.
I did see the analog graph spike many times, but not to maximum. The spikes were in the 100uS duration but they qualify as CAT III issues.Case point, I was troubleshooting a switching mode PSU 3 months ago that can output 300Vdc. As I was adjusting it and reading Vout, my Fluke was going berzerk, and wouldn't hold a reading after 180Vdc. I put a CAT II oscilloscope on it and bingo, the PSU was shooting transient spikes to 1000Vdc and it was briefly going out of range of the DMM.
Well I must ask what was the model ?
If the Bar-graph...... was unable to indicate the voltage overshoot !!
If the sign of the lightning on screen .... was unable to indicate the voltage overshoot !!
This DMM looks to have issues.
Thanks gobble^2. It can take a while to get through UL bureaucracy for final approval, and the vendor may want to get the product out before then, say to at least markets not covered by UL, CSA or the EU equivalent.
Thanks gobble^2. It can take a while to get through UL bureaucracy for final approval, and the vendor may want to get the product out before then, say to at least markets not covered by UL, CSA or the EU equivalent.
If the vendor puts the product on the market in the EU without it meeting the requirements they can be prosecuted. The EU safety requirements (CE mark) are a legal prerequisite for sale.
BTW – in a previous life I did safety testing and I have seen some horrible examples. The worst was a voltage probe as in Kiriakos-GR post. I applied the transient and the hand probe exploded. Every chip inside was damaged, and the main chip inside it was blown completely off the board. I'm also sure I saw some fire out of it. Needless to say we decided not to sell it. I must not that I have seen these things pass the best test we could give it. (8kV on 600V)
Neil
Yes sir. Just as the wikipedia states the CE mark is granted by the manufacturer to it's own products. UL and other similar marks require a third party to verify and can take some time. The original UEi had CE mark and therefore was completely legal to sell in EU. In fact, I'd be hard pressed to find a single multimeter in a supermarket that beared a UL or similar markings.
As far as the voltage testers go I believe I've heard a similar story, but the poor fellow was actually using the meter at the time of explosion. Fluke's equivalent bears a VDE mark though so I'm assumably on the safe side.
Speaking of actual testing, is there a list of what are the actual tests the meters have to pass somewhere in a "human readable" format? (I'm just a electrical student, not a scientist!)
The biggest problem with the CE mark is that it is not enforced. The EU require that that the rules are enforced by each country. For this reason most instruments have the CE mark on them - one story I don't know if true is that the defence said when it came to court that it stood for "China Export".
I know that the committee for the international safety standard for test and measuring equipment (IEC61010) had a complaint that the standard was not rigorous enough as there had been a spate of accidents with multi-meters in CATIII and CATIV locations. Further investigations showed none of the meters involved actually met the standard.
Companies can "Self certify" their products or they can get an independent test house to do it for them. Of course - if a manufacturer does end up in court having self certified the product and they do not have the correct paperwork then they could be faced with a very stiff fine (including paying for a mandatory recall) or prison for those directors responsible. (A fact I mentioned very loudly when asked to short cut corners on self certifying and I was only the test engineer).
Neil
The minimum is UL 61010-1 which is copied world wide.
* UL 61010-1 – for the United States market
* CAN/CSA 22.2 No. 61010-1 – for the Canadian market
* EN 61010-1 – for the EU market
* IEC 61010-1 – for CB Scheme Certification
I do not see anythingin the picture that says it has been tested an approved by VDE.
The reference VDE is to the standard it has been tested to, not the sign of approval.
UL is missing also.