Fluke fieldsense contactless voltmeter

[mikeselectricstuff]

This looks interesting - claiming 3% accuracy for >16VAC contactless voltage measurement. Presumably the key is to have a high enough input impedance that coupling capacitance becomes insignificant.
 
http://content.fluke.com/promotions/promo-eprod/uken.html?utm_campaign=IG-EU-MULTI-Newsletter-2017-11-UKEN

I think this is the patent - looks like they are comparing signals from a reference antenna at known position  :
 
https://www.google.com/patents/US20150331017

[macboy]

Did you mean "coupling capacitance becomes significant".
Looks like an interesting technology. I see that it measures both current and voltage simultaneously, without leads or a clamp.
I see it still has typical 600 V CAT IV, 1000 V CAT III rating. I wonder how long before they come up with a high voltage version?  Presumably without a direct electrical connection it should be easier to ensure safe higher voltage readings.

[HalFET]

I suppose it's due to the probes/leads at the bottom, this thing will probably easily achieve CAT IV over the whole line if they drop those. But I've been contemplating buying one just to see how it ticks inside, but they're a bit pricey for just that (150 EUR). Anyone has one of these already?

[mikeselectricstuff]

If I didn't already have  a pile of teardown items and not enough time I might  have splashed some Patron cash on one, but just too busy atm!

[Someone]

The manual says it works using the body of the user as ground reference, or the black test lead so there must be some serious shielding around the fork to reject adjacent wires.

[HalFET]

I might be mistaken, since I've been awake since 6:00 and the patent is heavily butchered legalese. But basically they seem to measure the electric field using an unspecified antenna shielded against excessive capacitive coupling. And then based on the impedance of the antenna and sensed element calculate the voltage, so I suppose they use the current to judge the impedance of the conductor. And one could infer the impedance of the antenna by loading a shield with a test signal I suppose? I want teardown photos of this thing and build my own 

[amirm]

The sole Amazon review doesn't give confidence that this really works: https://www.amazon.com/Fluke-4910269-T6-1000-Electrical-technology/dp/B076DYBHCW/ref=sr_1_1?ie=UTF8&qid=1511505552&sr=8-1&keywords=fluke+t6-1000

"Since Fluke refuses to publish my critical review on their own website, I'll post it here in the hopes it can help people make an educated purchase decsion...

I ordered this new technology skeptically shortly after product announcement. And it's about what I expected, and have heard from others while waiting for it to arrive. The FieldSense for voltage is pretty unreliable without a connection from the black lead to a good ground. Using the only the backside ground button/pad, I've gotten readings anywhere from 0 volts to 347 volts (how coincidental is that??) from a single 120v conductor while standing on concrete in regular work boots. I can't even trust it to determine if ANY voltage is present, because it has indicated -0- volts on energized conductors, while indicating that it had an "acceptable" earth ground. Same issue exists even if I am touching a good earth ground point that works for the single-lead method; so grounding yourself doesn't appear to make it any more reliable, even if the screen shows you have a "good" earth ground connection and turns green to indicate a "valid" reading.

And yes, I had the both leads docked in the storage slots (this is important) while attempting the readings.

Using FieldSense with the black/ground lead on a good ground seems to be reliable and accurate, so I'll give that method a thumbs up. Just wish it worked truly "leads-free".

The other features are worth the price though, love the backlit screen! Maybe this concept will get better in a few generations. So if you're thinking about a purchase, maybe hold off until the technology improves, accept FieldsSense as a "novelty" feature in lead-free mode, or go with the seemingly bulletproof T5.:

[mikeselectricstuff]

Fluke have just offered me one to look at.. stay tuned!

[sibeen]

AVE does not seem to be impressed. I may have even detected a rude word or three during the video.

[EEVblog]

Fluke offered me one to look at back in November, but I was like, meh.
I wonder if I now said "Hey, I've heard this really doesn't work, can I try one?" and see what they do 
Fluke Oz HQ is just around the corner from the lab.

[drussell]

Even more in the follow-up:

[mikeselectricstuff]

I never heard back after accepting an offer to look at one.

[Mukrakiish]

Watching both of AvE's videos back to back hasn't instilled me with a lot of confidence. What the heck is going on down there at Fluke? 

[mmagin]

Watching both of AvE's videos back to back hasn't instilled me with a lot of confidence. What the heck is going on down there at Fluke? 

Looks like Danaher spun off Fortive and saddled them with a shitload of debt.  I wonder if we'll see much good come out of Fluke or Tektronix ever again.

[RayOfLight]

I have calculated for this meter to have about 2MΩ input impedance using AvEs videos, is that bad for a voltmeter? (Also, I think measuring only up to 1kΩ proves that it has a kind of low input impedance, am I right?)

[ModemHead]

AvE is being an idiot and if Fluke insinuated that, they were correct.

Two major problems: 1) The black probe is supposed to be "docked" in the back of the unit to use the touch ground contact in the back.  It wasn't.  2) Even with a hard ground, he was trying to detect voltage on a big plastic Klein 10X line splitter.  With a coil in it.  And a neutral return somewhere in there also. Of course it didn't work.



At the end of vid #1 he had a slightly better arrangement, but really didn't insure that the conductor was in the prescribed location.  It was badly framed and hard to tell exactly where everything was.  Once the T6 became grounded it did briefly show a reading, but AvE had already decided to trash it, because that riles up the Fluke fan-boys vs. the AvE fan-boys and makes for more views on the ve-jay-oh.

I don't own one of these things.  I just read the quick reference guide.  And there are other (non-marketing) videos showing that it works when used by people who RTFM.  Even on 24Vac HVAC controls.  I wouldn't expect the accuracy to be all that great though.  It's spec'ed at (3% + 3d) with hard ground and (6% + 3d) for touch ground, valid from 16V and up.

[mos6502]

AvE is a retard. At least half of what he says is flat out wrong. He's really good at seeming to know what he's talking about, but he really doesn't.

[Cerebus]

AvE is a retard. At least half of what he says is flat out wrong. He's really good at seeming to know what he's talking about, but he really doesn't.

Easy to call a man a "retard" behind his back (what a charming line in talk you have), much tougher to actually support your casually flung out assertions. I challenge you to put your money where your mouth is. Pick a random, non-electronics video of his, and come back with the list of what he got right and what he got wrong. You hit less than 50% "flat out wrong", say you haven't got the time, say the dog ate your homework, or deliberately pick a video where the subject matter is obviously just opinion and you get to eat crow. No sauce, no bread, no potatoes, just neat roast crow, feathers optional.

[mos6502]

Jeez, you sound like I insulted your romantic interest. I would call him a retard to his face if you gave me his address and a plane ticket, but why? That's why we have telecommunications, dummy. I stopped watching his videos long ago due to the bad info and low-IQ "humor" (mispronouncing words hyuk hyuk). But interesting you would say "non-electronics". That's because you know about electronics and realize, he doesn't know shit about it. Which doesn't stop him from giving products that he doesn't understand bad reviews, or making instructional videos about electronics.

[Mr. Scram]

Jeez, you sound like I insulted your romantic interest. I would call him a retard to his face if you gave me his address and a plane ticket, but why? That's why we have telecommunications, dummy. I stopped watching his videos long ago due to the bad info and low-IQ "humor" (mispronouncing words hyuk hyuk). But interesting you would say "non-electronics". That's because you know about electronics and realize, he doesn't know shit about it. Which doesn't stop him from giving products that he doesn't understand bad reviews, or making instructional videos about electronics.

Can you make a list where over half is flat out wrong with electronics included, bar the two videos we're discussing now?

[drussell]

Which doesn't stop him from giving products that he doesn't understand bad reviews, or making instructional videos about electronics.

Uhhh... So where is your review of this product, with all your test specs and measurements, showing how fully wonderful it is in every aspect to rebut his "industrial" style review?

[joeqsmith]

This looks interesting - claiming 3% accuracy for >16VAC contactless voltage measurement. Presumably the key is to have a high enough input impedance that coupling capacitance becomes insignificant.
 
http://content.fluke.com/promotions/promo-eprod/uken.html?utm_campaign=IG-EU-MULTI-Newsletter-2017-11-UKEN

I think this is the patent - looks like they are comparing signals from a reference antenna at known position  :
 
https://www.google.com/patents/US20150331017

Thanks for digging into this.   It's a bit strange that GE holds it as Fluke's paper talks about them developing the technology.   Based on the little info Fluke made available, this does seem to be close to what they describe with their reference but maybe it's totally different. 

Even though these couple of videos make it look bad, there are several (not just Fluke's) showing it in operation and it looks pretty impressive.  There were a few where the reviewers just talked about how good it was and never do anything with it.   The lack of good information peeks my curiosity.     

The sensing technique seems pretty interesting.  I've made capacitive HV probes before but nothing like this with a reference.  It makes sense.   Maybe another hack for my UNI-T UT210E ....

[Rabid Badger]

The placement of conductor in the fork is awfully finicky. When I'm checking for potentially lethal levels of electricity, finicky isn't on my list of desired features.

As for the grounding pad on the back, that just seems like trouble. Is it a high-impedance path under normal conditions? Yes. Now what happens in a gross overload condition when a couple internal components vaporize and the inside of the unit is filled with conductive plasma?

Finicky gimmicks aren't what made Fluke the most trusted name in hand-held meters.

Edit  (grammar)

[joeqsmith]

The placement of conductor in the fork is awfully finicky. When I'm checking for potentially lethal levels of electricity, finicky on my list of desired features.

As for the grounding pad on the back, that just seems like trouble. Is it a high-impedance path under normal conditions? Yes. Now what happens in a gross overload condition when a couple internal components vaporize and the inside of the unit is filled with conductive plasma?

Finicky gimmicks aren't what made Fluke the most trusted name in hand-held meters.

Do you have a way to test how finicky it is?  This is what I would have liked to have seen in a review but was unable to find one.  Different wire sizes, insulation thicknesses, voltage levels.....  Lots of tests could have been run so show it off. 

No one measured the current through the meter with it in all of the modes using the meters highest rated voltage.  Or at any voltage for that matter.   

When you remove the ground lead from the rear, you detach the button.  May be ok.   When you have the ground lead installed, the human holding it may be enough to prevent the meter from overloading and creating a plasma.   If you can get the GDT to break over, say 2KV,  you have say a 1.5K resistor now in series with your body....    Hard to say.  I assume they certified it for safety. 

Then again, I bought a Gossen that can throw up low voltage readings if it gets near a magnetic hanger.      I'm sure it passes the safety standards but it seems IEC never considered a magnetic force like this.   Gossen's marketing people may not have listened to the engineers who thought it was a bad idea to put unshielded latching relays in a meter.     Maybe there are things with this meter that IEC did not consider, like using a human as a return path.     Too bad the manufacture's and other big players never weigh in here.   We could all learn a lot from the experts. 

[joeqsmith]

Screen shots from the video showing some of the front  end.  I can't tell how it is arranged but I wonder now if the GDT/PTC are both on the backside of the switch rather than the front.   If so, this is the first time I have seen a Fluke designed like this.   

If the meter were set to ohms (anything that engages this clamp) and the ground lead is in the holder so your body becomes the return path, the red lead is attached to line and a transient higher than the GDT rating is applied, could you harm a human.     

I have a small pocket contact voltage detector that uses the human as a return path.  I transient tested that unit from the tip to the ground plate and it still works today.  That detector can't measure anything and always has a very high resistance.   Still, I wouldn't risk using it.     This Fluke is a different story.    We need a much better review of one than what I have been able to find.