Handheld meter robustness testing

[TheAmmoniacal]

Yeah, kids in Africa could have eaten those meters! 

When will we see part 2 on the Gossen? The suspense is killing me!

[IanB]

I'm sure mzacharias is not the only one who cringes slightly at the destruction of perfectly functional items, even if it is in the name of science.

What a meter may lack in robustness it may make up for in other qualities. For example, the Radio Shack 22-812 meter that doesn't have very good input protection. It is a meter that I rather like for it's PC communication and data logging capabilities. I wrote software that allows me to plug two, three or any number of them into a computer and log measurements from them all simultaneously, something that the data logging programs from meter vendors do not typically allow you to do. Add to that that the meter is (was) inexpensive enough that it was actually practical to own two, three or more of them.

I would like to add the BM869s to my logging system, but the vendor's cable requires me to figure out how to program against the USB interface, and I cannot find a simple serial interface for it unless I make one. And even if I did, the 869 costs way more than the 22-812, so owning lots of them is not so easy to consider.

[MacMeter]

Yeah, kids in Africa could have eaten those meters! 

When will we see part 2 on the Gossen? The suspense is killing me!

Gonna need to stock up on more POPCORN!

[joeqsmith]

Would the Fluke 114, 115, 116, 117 series survive carpet surfing reasonably well such as the 101 or 107?

I need the TrueRMS, min max and Low Z features which 101 and 107 lack

My 114 has held up well so far, not that I have done any serious deliberate carpet surfing with it.. yet 

That said, if I have to spend $100 (on yet another meter  ) that will survive carpet trekking in an office to office client troubleshoot scenario,
what choice is there ? 

BTW:  what's the continuity buzzer like on the 101 and 107?  If it's not typical  'Fluke Speed' the meter is a no go for me.

Of course, after seeing that report I linked where the lab did not directly test the leads, it does tend to water down the consumers trust (or at least my trust) in independent  certifications.  Or maybe I am doing it all wrong and the UNI-T would have survived.    IMO, the leads would be tested but I have seen reports like this before.   The Gossen and the 121GW if/when it becomes available will also be tested this way.  Direct discharges to the inputs.   

Anyway, I have only tested the Fluke 101, 107 and 115.  All certified for the EMC standards.  All can survive the puny grill starter and the new gun.  The 115 does tend to hang but I have yet to kill it.  These are direct discharges to the ports.   My guess is you would be hard pressed to damage your 114 this way but I have never looked at one.  I wouldn't run out a but a new meter if the 114 does what you want.   

You could prove it to yourself and try to damage your 114 by petting your cat, sliding across the carpet, whatever you can come up with for ESD around the home or lab.  Then post about it.   

[joeqsmith]

For continuity, I measure the open circuit voltage, short circuit current, 50% DC, max frequency before meter skips, lowest detectable pulse, short circuit resistance and resistance that it opens back up.  I do not measure the beepers sound pressure or the audio frequency.  I also don't record if they latch or not.   

I have data for both the 115 and 101 but I never measured the 107. 

[P90]

Thanks,  I will assume the 114 and 115 will have same performance being the same build style

and same deal with 101 and 107

perhaps, but never assume anything...

[Fungus]

Would you know how well the continuity buzzer on the 101 and 107 compares to the 115?

If only there was a spreadsheet somewhere with actual data on this... 

[bitseeker]

...

I can always count on you adding to the technical discussion.     Did you need to add or remove a period? 

I posted a link to a picture of a nasty exploded glass fuse inside a meter... then I thought it might not be such a good idea, and I couldn't delete the post...

Ah, mystery solved. In such cases perhaps it would be helpful to put something similar to "-- post deleted --" in the body to minimize confusion, speculation, and the like.

[P90]

...

I can always count on you adding to the technical discussion.     Did you need to add or remove a period? 

I posted a link to a picture of a nasty exploded glass fuse inside a meter... then I thought it might not be such a good idea, and I couldn't delete the post...

Ah, mystery solved. In such cases perhaps it would be helpful to put something similar to "-- post deleted --" in the body to minimize confusion, speculation, and the like.

Indeed, good point...

[totalnoob]

I have a ceiling fan and needed to replace its switch.  Drove to all the local stores and could not find one switch that was UL rated.  This switch has the potential to cause an electrical fire.  I would GLADLY pay for a good certified switch but there are none to be had.   We do not make them here anymore that I have found.   I doubt the average consumer will care unless something happens.  Even then my guess is the finger would be pointed at the installation and not the switch itself.  There used to be public service announcements to help educate the general population about things like UL.  Now we talk about quality rather than practice it.  Fan I would guess is I would imagine nearing 40 years old now.  The larger white switch is make by KTE and was the original The smaller switch is what I used to replace it.  Note the CSA and RL marks on it.  The pull mechanism in this switch failed in maybe 5 years or so.  That's how bad the quality is.   The new switch is even cheaper made with no cert.   

You can't always trust something that is stamped with a "UL" label, either because it may be faked.

[totalnoob]

While I'm not sure about the frequency of the surges, without a doubt they do happen. A local employer, a mining operation, had a electrician injured when he was measuring receptacle voltage (995V Phase to Phase), apparently the PT's onboard the equipment were acting up and they were unsure as to why. When the electrician measured phase to phase the meter had an internal arc and pulled a arc on the terminals of the receptacle when he attempted to pull away. The meter was a Southwire meter, they eventually had to pull it due to a failed IP67 rating, you could try googling MSHA (Mine Safety and Health Administration and Southwire) and you might find something I'm not sure. I believe the IP67 failure was not a factor in the accident but it came up during the investigation.

Edit: Found it https://arlweb.msha.gov/Alerts/Equipment/2014-11-21-southwire%20alert.pdf

Jordan,

I am not an electrician, I am a Facilities Engineer (Mechanical) and my company offered a training course on NEC's Arc Flash standards, a few years ago, that I took and learned quite a bit.  In my job, I don't actually open up equipment and put a meter on them, I would have our in-house Electricians do that, however, I do need to sometimes look on as an Electrician or Controls Mechanic troubleshoot a piece of equipment, so I do need to be aware of arc flash dangers and what to look for.  However, while I am not an Electrician, I know enough to get into trouble and to avoid trouble  and I am inclined to say that a multimeter is wrong device to measure voltage when you are that close to most multimeter's design limits (i.e. 995V circuit is too close to a typical industrial multimeter's 1KV limit, which is what most multimeters state are their limits, and those that aren't typically have a much lower rating).  One of the ex. in that class was an HVAC technician trying to troubleshoot a 4160V, chiller.  There was the HV side and a LV side (not sure what the voltage on the LV side was, but it was used for the chiller controls), the tech found that the LV side appeared to be OK, so without thinking he hooked his multimeter to the HV side and the next thing he knew there was a flash of light (the meter "blowing up") and he was on fire and running through the building.  He lived long enough to tell his coworkers that he realized he used the wrong tool for the job. Like I said, I am not an Electrician, therefore I don't know what's available to use to measure voltage drop for high voltage circuits, but it seems to me that a multimeter is the wrong device, or at the very least marginal, even at the lower end of NEC's definition of High Voltage circuits (600V and above).

[totalnoob]

I would like to know how often in the real world a surge or some other anomaly comes along and puts a technician at risk while in the process of troubleshooting a fault in a piece of (let's just say consumer) equipment.

Since I discovered this site which has always stressed getting meters that meet their CAT ratings, I have wondered the same thing myself, only from a slightly different perspective, I always felt that if these surges were so common place, then there'd be be tons of folks crying about their busted electronics, like their 'spensive, flat screen, UHTV's, computers, smart phones (while charging), etc. I am sure they are not "hardened" for what would be considered CAT 2 transients, like a Fluke or other reputable multimeter, so there should be many failures of these kinds of equipment.  And, if it were really a problem, there'd be an outcry to harden electronics to survive these transients.  At least in the US, you don't really see that, which leads me to believe overall the US has fairly clean electric supply (as opposed to generation, but that would be a different discussion ), but as others have said, that may not be the case in other parts of the world, so a meter that meets its CAT rating may be more of a necessity in those areas.  I have not known anyone who has lost a piece of electronic equipment due to a transient unless lightning was involved.     

But, that said, I do understand the position of this site, its hard to argue being less safe and recommending meters that will obviously not meet their CAT ratings and could potentially put someone's life in danger if, for example, an Electrician is lead to believe that an UT-66E is just as good as a Fluke IV for much less, and the Electrician proceeds to buy and use his UT-66E on industrial equipment.  I think that is why people stress that the UT-66E (and other inexpensive multimeters) is perfectly fine if your plan is to use it on what most folks refer to as "LV" circuits (i.e. <120V) and don't recommend using it to measure inside your electrical panel. 

[saturation]

DMM in particular, are expected to be used in fault conditions to its appropriate CAT rating, not clean line power used by consumers.  Most PSU are made with surge in mind the ITIC curve is the common standard:

https://www.eevblog.com/forum/chat/understanding-%27itic(cbema)-curve%27/

In real world use surge exposure depends on what you do.  If you are an electrician working any source of inductive loads or outdoors during bad weather, even far away from your location, CAT III and IV conditions occur fairly daily.  The only times I've been hit was working outdoors on land or ship board electronics. 5x in 30+ years but I'm not a service engineer or tech, and was doing field testing of electronic devices and normally not exposed to such spikes.  Its not life threatening in my application, but being without a DMM miles from civilization and no way to do measurements, pretty much ends the installation.  But if we use a true Fluke DMM, we never have problems no matter where we go.

[rsjsouza]

I would like to know how often in the real world a surge or some other anomaly comes along and puts a technician at risk while in the process of troubleshooting a fault in a piece of (let's just say consumer) equipment.

Since I discovered this site which has always stressed getting meters that meet their CAT ratings, I have wondered the same thing myself, only from a slightly different perspective, I always felt that if these surges were so common place, then there'd be be tons of folks crying about their busted electronics, like their 'spensive, flat screen, UHTV's, computers, smart phones (while charging), etc. I am sure they are not "hardened" for what would be considered CAT 2 transients, like a Fluke or other reputable multimeter, so there should be many failures of these kinds of equipment.  And, if it were really a problem, there'd be an outcry to harden electronics to survive these transients.  At least in the US, you don't really see that, which leads me to believe overall the US has fairly clean electric supply (as opposed to generation, but that would be a different discussion ), but as others have said, that may not be the case in other parts of the world, so a meter that meets its CAT rating may be more of a necessity in those areas.   

I am not an expert in this area, but I think that outcry may have happened and thus HiPot testing is used to address this concern for consumer electronics and appliances. Reading this article seems to confirm that.

I have not known anyone who has lost a piece of electronic equipment due to a transient unless lightning was involved.

One example of non-lightning issue is what I saw happen in my hometown (1980s in Brazil): a neutral ground interrupt fault, which raised the voltage of the phase wires to the point of internally arcing and damaging some of the consumer equipment and appliances. That was dangerous but fortunately there were no cases of electrocution.

Another problem that was caused by lightning and became very frequent were transients in telephone lines, which started to become more expensive when household modems came around. I have seen arcing in boards and DMMs while probing these lines at the wrong time.

[jordanp123]

You actually run into a mine field of issues on this, most mining operations (One's that are coal or ones which have been classified as "Gassy") in the US have to meet requirements for permissibility in certain mining area's(almost equivalent to Class 1 Div 1 in the NEC), only a few such meters meet that requirement (The southwire did not), though in the location it was discovered it wasn't required. The other requirement (not a legal one) is for it to be rugged, these meters in the mining environment are dropped in mud, have rocks fall on them etc.. If this isn't enough the equipment is always advancing as well, the power system at the "face"  (13800VLL is common) is typically moved once per week. In a nut shell it comes down to what equipment is available to use, that's the reason for the "Best practices" of measuring phase to ground ( The system is also resistive grounded - 25 Amps max current). Most equipment which could be used that would more adequately meet the voltage rating (Buying margin on the voltage) would also lack in the durability. It's a trade off, I will say if you search the MSHA website for electrical accidents very few, almost none, are due to the meter it's self failing, that I could fine anyway.

[joeqsmith]

Part 2 showing a little more detail on the proximity problem.  For Part 3, I plan to run the continuity tests and then write some LabVIEW code to interface with the meter.  I had recently ran some tests on my UNI-T UT181A where I held the temperature somewhat constant with the inputs to the meter shorted and plotted the drift.  This was to compare the meter with various Fluke 289's that other members had collected the same data from. That thread may be found here:

https://www.eevblog.com/forum/beginners/is-my-new-fluke-289-multimeter-faulty/

I plan to run this same test with the Gossen. 

My plan is to give Gossen a couple of weeks to respond to the email I sent them on the 10th asking about the proximity problem.  I'm sorry to have to say that they have not even sent an acknowledgment of the email.     

Hope you enjoy the video.   

[Wytnucls]

I don't have the same meter, but I can report that the Gossen MetraHit 30M, which reads down to 100nV doesn't behave like that at all. It only shows some minor fluctuation on the last digit.
The MetraHit 26S, with has a resolution of 10uV, is rock solid, to the last digit.

[MacMeter]

Reminds me of the Apple iPhone 4 "Antenna Gate" debacle.
In addition to the email you sent them, send a link to this thread and the 2 YouTube videos you made. You may find you get a faster response as few companies want any negative comments or findings spread on the internet.

[Wytnucls]

Reporting the fault in the German language should provide a quicker answer.
I doubt such a mV behavior would be acceptable to Gossen. That meter must be faulty, but we shall see.
mailto:Support.industrie@gossenmetrawatt.com
http://gossen.ofactory.biz/services/produkt-support/allgemeine-hinweise/

[Fungus]

Reporting the fault in the German language should provide a quicker answer.
I doubt such a mV behavior would be acceptable to Gossen. That meter must be faulty, but we shall see.
mailto:Support.industrie@gossenmetrawatt.com
http://gossen.ofactory.biz/services/produkt-support/allgemeine-hinweise/

The best thing is to point them to the video.

Any German readers want to fill in the support form?

(I'm sure they'll understand English if I fill it in, but...  )

[Fungus]

I can't imagine the thing isn't shielded inside. Maybe the shield isn't connected properly.

Take it apart and have a peek inside.

[joeqsmith]

I can't imagine the thing isn't shielded inside. Maybe the shield isn't connected properly.

Take it apart and have a peek inside.

Removing the cover voids the warranty.  From watching Dave's video on the Energy, I suspect there are other latches and that is why he uses the screwdriver.  Maybe the meter broke when he pried it apart? I have no idea.  I asked.  I will pull one of them apart at some point and it would be good to know if there was a trick to getting it apart.   

The other problem with taking it apart is like we saw in one of Dave's recent mailbag videos were he was sent a box of brand new meters.  He does a quick teardown and then the meter does not work.  It raises questions if the meter was damaged during the teardown.  We have no idea. 

This meter (or another of the same model) will come apart once I have completed all of my basic tests.  I want it to be VERY clear to people that this is how the meter worked when I received it. 

https://www.eevblog.com/forum/blog/eevblog-173-gossen-metrahit-energy-multimeter-teardown/

[joeqsmith]

I don't have the same meter, but I can report that the Gossen MetraHit 30M, which reads down to 100nV doesn't behave like that at all. It only shows some minor fluctuation on the last digit.
The MetraHit 26S, with has a resolution of 10uV, is rock solid, to the last digit.

It would be nice to hear from someone with the exact same model to see if they see the same problem.   For now, I plan to just wait on Gossen while I work on some software to support it. 

[joeqsmith]

Reminds me of the Apple iPhone 4 "Antenna Gate" debacle.
In addition to the email you sent them, send a link to this thread and the 2 YouTube videos you made. You may find you get a faster response as few companies want any negative comments or findings spread on the internet.

The only real problem I see so far is someone who is dealing with customers blocking their email for simple questions.  With Gossen now owning them, it really does fall in their court to address it.  I've seen other meters come in defective.  Granted, I buy some pretty low end products.  Give Gossen a chance to decode my email. 

[P90]

I can't imagine the thing isn't shielded inside. Maybe the shield isn't connected properly.

Take it apart and have a peek inside.

Removing the cover voids the warranty.  From watching Dave's video on the Energy, I suspect there are other latches and that is why he uses the screwdriver.  Maybe the meter broke when he pried it apart? I have no idea.  I asked.  I will pull one of them apart at some point and it would be good to know if there was a trick to getting it apart.   

The other problem with taking it apart is like we saw in one of Dave's recent mailbag videos were he was sent a box of brand new meters.  He does a quick teardown and then the meter does not work.  It raises questions if the meter was damaged during the teardown.  We have no idea. 

This meter (or another of the same model) will come apart once I have completed all of my basic tests.  I want it to be VERY clear to people that this is how the meter worked when I received it. 

https://www.eevblog.com/forum/blog/eevblog-173-gossen-metrahit-energy-multimeter-teardown/

I agree. I often wonder about that too. I see Mr. Jones take some equipment apart and poke around in there with a metal screwdriver, pointing out the various components, possibly scratching fine traces, and in the process perhaps damaging something BEFORE testing the product, and proceeding to call the item in question, "a heap of garbage" after discovering later it does not function properly. Case in point, the Global Specialties meter in one of the multimeter shootouts. It's not fair to a product to take it apart before testing it. Was it damaged before it arived? Not a very scientific way to test something...