Multimeter choices for rural/outdoor use

[bernroth]

Hello all!

Browsing though the topics of the forum about multimeters, people ask often about the best, full featured, reliable, feature blown, µA range multimeters for the lab.
I am a proud owner of an Agilent U1272A and a Gossen Metrawatt Energy meter which I use in my lab. I am very satisfied with them  O0

Now I would like to purchase a multimeter for usage in tough environments, more specific in Mexico on an seaside property, like for debugging the local power installations (probing 110V power cables in the fuse box, measuring resistances etc...). There is already a little cheapo china meter which I don't like to use at all because it's just crap and insecure. Anyways the battery is already empty and leaky.
Well, I have found meters like a Gossen Metrahit Tech/Pro for around USD $200 but I don't think that a precision meter like the gossen is adequate for that use case.
It should be protected against water and dust and survive a bit of sun exposure without the display to fail.

What would you recommend? I would like to go for the Gossen because of the price. A metrahit outdoor would be adequate but for ~ USD 700 quite expensive. Some risk of the meter getting stolen is always present. Are there some good Flukes or Agilents suitable for this usecase?

Maybe someone has one to sell? 

Regards,

Bernhard

[Bored@Work]

Is that robust enough for you?

[bernroth]

Yeah, that's robust indeed but quite pricey. Does it get hard to find something in the < USD 200 range?

[Wytnucls]

Since you don't want to spend a fortune on a Fluke 28, have a look at the CEM range of IP67 waterproof meters:

http://www.cem-instruments.com/en/pro/nsort14-1.html

[Bored@Work]

CEM? Are you serious?

[Legit-Design]

Are there any websites with parametric search for this, I checked farnell and digikey, neither included environmental ratings in their parametric search. Mouser has "Handheld, waterproof" but that only includes three extech meters, hardly the same thing as separate column for IP-rating/waterproof.

I mean real parametric search like with http://geizhals.at/de/ thats the most awesome thing for searching computer parts/cameras/camcorders full parametric search with real pricing. Even if I don't live in any of the countries they deliver to, I can still use it to find something, without having to do my own list, or searching for some half assed reviews. For example I search for ssd in certain pricerange or best bang per buck (€/GB). Or camcorders with certain sized sensor with optical image stabilization, and it should be as cheap as possible, my first step is to go to parametric search.

[Wytnucls]

Well, you can't have your cake and eat it.
I'm talking second best option here.
Sturdy IP67 meter, CAT III 1000V, GS listed, that doesn't cost a fortune.

[bernroth]

Any opinion about Extech EX510?

[dds]

Fluke 25? Military version, used surplus from Royal Air Force tough as hell

[bernroth]

Where to get these used Fluke 25 from? Sounds very interesting but nothing found on eba...

[dds]

http://www.ebay.co.uk/itm/Fluke-25-Multimeter-with-case-and-probes-/221282936090?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&hash=item33857da51a


Watch ebay.co.uk for fluke 25

[Wytnucls]

Out of calibration! No Max/Min and no 'Relative' mode on the 25 model. Quite sturdy though, but I'm not sure if they are water proof or not. Very similar to the 27 model.

[Wytnucls]

Any opinion about Extech EX510?

Rugged design IP67, but no GS listing and there have been quite a few reports of shoddy workmanship on Extech meters in general.

[alm]

Rugged design IP67, but no GS listing and there have been quite a few reports of shoddy workmanship on Extech meters in general.

Shoddy workmanship on Extech meters produced by CEM?

[Wytnucls]

I was waiting for that one.
They may have different assembly lines, because the CEM-branded meters don't have the same problem.

[dds]

I will trust my life for checking mains voltage to uncalibrated  Fluke 25 , not to some Extech crap. I own two  Fluke 25 (both are military version) I'm very satisfied with them. Just my opinion

[dds]

Out of calibration! No Max/Min and no 'Relative' mode on the 25 model. Quite sturdy though, but I'm not sure if they are water proof or not. Very similar to the 27 model.

It looks like that Fluke 25 is waterproof:

http://roscigno.com/FLUKE_25_27.pdf

[KJDS]

Where to get these used Fluke 25 from? Sounds very interesting but nothing found on eba...

Purely by coincidence, I collected 20 of them yesterday, haven't tested any yet so no idea how many of them work.

[danb35]

A used Fluke 27 would be an option as well.  Very rugged, I believe they're supposed to be waterproof, and last I looked there were tons of them on eBay as military surplus.  Certainly should be < $100, and you may find around $50 if you're lucky.

[KJDS]

I've now tested a few, £45 delivered to mainland UK, I'll find out postage for Western Europe tomorrow. Postage for further afield on request. They are a little scruffy, showing obvious signs of being used and some have serial numbers painted on but they are working well.

[Lightages]

I think I would pick a good used Fluke 25 or 27 anytime over any CEM. I have to confess I have never held a CEM so I can't be sure they are crap  but from the experiences people have had with the Extech re-brands I would avoid them. I would seriously doubt that CEM would have a dedicated assembly line and better trained workforce for their meters over the Extech models.

[Wytnucls]

Most of the new CEM models are now IP67, GS TUV tested and have proper input protection, with HRC 1000V fuses. I don't have much experience with them either. I do own the CEM DT9935 LCR meter which is reasonably well made and works as advertised and a cheap Velleman rebrand, which hasn't given me any problems either.

CEM production base is located in Shenzhen, China, with 1000 + employees, five production plants and 20 production lines.

[mmagin]

[...] like for debugging the local power installations (probing 110V power cables in the fuse box, measuring resistances etc...).

This sounds like a very good reason to use a meter where you can trust the validity of the CAT III/IV certification.  I'd prioritize that over the level of dust/water protection (though it's probably worth getting something that can take dust and a little rain, it sounds like whether it can take immersion is a distraction from the original question.

[Lightages]

Another alternative perhaps?
http://www.testequipmentdepot.com/amprobe/multimeters/hd110c_hd160c.htm

I have no experience with this neither but I tend to trust Amprobe's quality.

[Bored@Work]

Well, you can't have your cake and eat it.
I'm talking second best option here.
Sturdy IP67 meter, CAT III 1000V, GS listed, that doesn't cost a fortune.

Well, exactly that DT-9949 is dubious.

When I search for it in the TUV database I end up at a certificate AN 50225998 http://www.certipedia.com/certificates/50225998 But for whatever reason the DT-9949 is not mentioned in the certificate data. Further, the certificate is for EU low-voltage-directive conformance. The description of that particular test contains the following

The EC declaration of conformity refers to the tested sample as stated in the certificate. It certifies that this sample complies with the safety objectives according to the latest version of Low Voltage Directive Annex I. The certificate does not refer to serial production of the product and it does not authorize to use a TÜV Rheinland test mark.

So even if this happens to be the certificate for the DT-9949 it does not allow to use the TUV and GS mark.

I'd rather use a brand where they have their shit in order and where the risk of "spontaneous" cost savings during production is low.

[Stonent]

Honestly I'd just get a throw-away meter if I was travelling. Your requirements are not very high so pick up a cheap CATIII or CATIV rated meter sold at a hardware store in the electrical wiring department.

[Lightages]

His point was to have something safe and durable, but not too expensive. A "throw away meter" is what he already has and there is no such a thing as a "throw away meter" with true CATIII ratings.

[EEVblog]

On old Fluke 27

[Wytnucls]

Well, you can't have your cake and eat it.
I'm talking second best option here.
Sturdy IP67 meter, CAT III 1000V, GS listed, that doesn't cost a fortune.

Well, exactly that DT-9949 is dubious.

When I search for it in the TUV database I end up at a certificate AN 50225998 http://www.certipedia.com/certificates/50225998 But for whatever reason the DT-9949 is not mentioned in the certificate data. Further, the certificate is for EU low-voltage-directive conformance. The description of that particular test contains the following

The EC declaration of conformity refers to the tested sample as stated in the certificate. It certifies that this sample complies with the safety objectives according to the latest version of Low Voltage Directive Annex I. The certificate does not refer to serial production of the product and it does not authorize to use a TÜV Rheinland test mark.

So even if this happens to be the certificate for the DT-9949 it does not allow to use the TUV and GS mark.

I'd rather use a brand where they have their shit in order and where the risk of "spontaneous" cost savings during production is low.

Here is the last updated (July 2013) list of the CEM meters that have been tested and which are allowed to bear the TUV GS mark:
http://www.certipedia.com/companies/33446/certificates_by_product?additional_title=Digital+Multimeter&locale=en&title=Multimeter

Some of the recent meters may have been tested already, but do not appear on the list yet.

You can always report CEM for unlawful use of the certificates if you're not convinced:
'In case a GS Mark has been attached to a product without permission - that is without the relevant tests, certification and factory inspection - corrective measurements against the unlawful user will be implemented on the spot.'

[EEVblog]

Another alternative perhaps?
http://www.testequipmentdepot.com/amprobe/multimeters/hd110c_hd160c.htm

They do look pretty darn good. Is there a better input rated meter?
An upgrade to the old Wavetek HD110 I'm assuming.
Amprobe is of course owned by Fluke, and I have been told that all Amprobe meters undergo full Fluke in-house testing certifications for their ratings. So yes, I'd trust Amprobes ratings.

[alm]

That's interesting. Why would Fluke introduce a CAT IV 1000 V meter under the Amprobe brand? You would think the Amprobe brand is for people who don't want to pay extra for the Fluke name (and presumably quality). Introducing a CAT IV 1000 V meter while the highest Fluke goes to CAT IV 600 V (as far as I know) does not fit in that picture. Would a CAT IV 1000 V meter under the Fluke brand require more rigorous testing? Are they taking risks they don't want to take with the Fluke brand? Is this intended for a different market that they serve through the Wavetek brand?

[EEVblog]

Would a CAT IV 1000 V meter under the Fluke brand require more rigorous testing?

Maybe not. But it does need to the made in the USA instead of China to to sold in the Fluke US market.
And it's designed by a different group I believe.

[Wytnucls]

The Amprobe meters are limited to a 2A range only, weird!
How useful is that?

[alm]

[Maybe not. But it does need to the made in the USA instead of China to to sold in the Fluke US market.

The Fluke 115-117 is made in China and sold under the Fluke brand in the US, isn't it?

I'm guessing 11A fuses of suitable ratings would be prohibitively expensive. The ones Fluke use may not be enough for CAT IV 1000V. 2A is perfectly usable for many applications. Most battery powered consumer gadgets, for example. Many older meters were limited to 2-3A, and power usage has gone down since the days of discrete transistors and TTL. I can't really see the CAT IV 1000 V crowd breaking the circuit to measure current. That's when the clamp meters shine, especially for currents above 1A.

[Wytnucls]

I don't think it is a question of prohibitively expensive fuses. The Amprobe 2A fuse sells for 13$ for a set of two. Just as well, as with a range of 2A only, one can expect to blow fuses on a regular basis.



They are probably made by Mersen or a similar company and are available in different Amp ratings:
These ones are quite long though at 120mm and I don't have the dimensions of the Amprobe ones. Actually, they are half the size at 65mm.

[alm]

That would be tricky to fit into a meter . Especially if you want fuse access through the battery door.

But what I was referring to was that the 10A range would probably need a fuse with an even higher interrupt current rating, since the shunt resistance, and the effective impedance as seen from the fuse, would be lower. I believe the 440 mA and 11 A fuses used in many Fluke meters also have different ratings. The 440 mA fuse is 10 kA while the 11A fuse is 20 kA, IIRC.

[Wytnucls]

Hey, you could load them like torpedoes on a submarine (Should get a patent for this...)  .

The CAT IV 1000V rating for the fuse only requires no arcing in the meter for 1 minute, with a ruptured fuse in place at double the rated voltage (i.e. 2000V). This is the same requirement as the CAT III 1000V. The difference between CAT III and IV, in this instance, only concerns the voltage range, with higher transients for CAT IV. A CAT IV 1500V rating would need a 3000V arcing test on the amp range for 1 minute.
The HRC fuse must be certified for the highest voltage and should withstand a minimum of 50kA or 1500V/shunt, fuse and leads impedance, if lower. The voltage source must be capable of delivering at least 500VA.

[retiredcaps]

Now I would like to purchase a multimeter for usage in tough environments, more specific in Mexico on an seaside property, like for debugging the local power installations (probing 110V power cables in the fuse box, measuring resistances etc...).

What range do you need for resistance measurements?  Do you need to measure more than 4000 ohms (4K)?

[Robomeds]

I like the idea of the Fluke 8025/25/27 but would the 113 do the trick?  They are horrid bench meters because they only have a low Z voltage testing mode but they might work well for the job.  They aren't water proof but neither is the 87 and it's known for ruggedness.  The 113 would work well for checking AC lines.  Its certainly a durable meter (check out Dave's 117 review, same meter family).  They also can be had almost new on ebay for $40. 

[AG6QR]

If it were me, and I were going to use it to probe around in mains distribution panels, fuse boxes, and such, near salty air, I'd wouldn't negotiate on two criteria:  Safe CAT III protection, plus at least enough dust/water resistance to maintain that Safe CATIII protection.  A meter might be very safe the way it came from the factory, but if it is exposed to salt spray for a few years, those carefully designed creepage clearances might not be maintained.

Ideally I'd like something with at least IP67 certification, and I'd rinse it off with fresh water after every exposure to salt air.  I'd might settle for dust intrusion protection.  But if I got a meter with no certification on its case, I'd be periodically opening it up and checking the circuit board to make sure it wasn't getting salt buildup or corrosion.

To save money, I'd go for a used Fluke 27 or similar meter out of calibration.  Utmost accuracy doesn't seem as important as safety/waterproofing for this particular scenario.

[bernroth]

Thanks to all for your responses. I try to reply to every question

@AG6QR:

You got the point, there is a lot of salt in the air and I agree to all what you wrote.
I will definitely check the board of meter every once a while to make sure there are no salt residues. I have some plastic boxes there to keep all my tools to avoid them to rust.
Last time I had there some hyper quiality swiss steel tools and after some time even them got rusty.
I have not yet found a used fluke 27 at a reasonable price, I will continue watching

73

@retiredcaps:

For resistance measurement I will require more than 4k because most of the wires have been put underground and there might be a measurable resistance of maybe some 10th k between the phase and earth 
Typical mexican installation unfortunately. Electricians tools there are shovel, wire and black pvc tape



In the meantime I scored a reasonable priced Extech EX510 meter for USD $45 and I might get it today in my hands.
As we have learned I will take it apart first, check if it meets international and my ambitious quality and safety standards and then turn it on
I will post some pictures of the inner workings of that meter.

If I find another reasonable priced Fluke, I will take it into consideration.

These thow-away meters from the local tool store are crap - sorry. If not the electrical 110v installation or the insane SWER transformer puts your life in risk, the meter will do

[retiredcaps]

In the meantime I scored a reasonable priced Extech EX510 meter for USD $45 and I might get it today in my hands.
I will post some pictures of the inner workings of that meter.

Yes, please provide pictures of the insides (both sides of the pcb).

I'm trying to keep an open mind about the CEM made multimeters especially the soldering quality inside on the pcb.

[bernroth]

Today I received the meter and took some pictures of the inside.
The solder quality is not the best but okay except for the joints on the current sensing shunt.
I wonder why they put a huge ball of solder on the shunt itself, maybe for tuning?
The long red (but isolated) trace which goes from the common input to the shunt is bad design IMHO.
I wonder how they can claim that this meter supports 20A max current (see the specs at http://www.extech.com/instruments/product.asp?catid=48&prodid=266) using a 10A fuse and a crappy shunt. Okay, they spec 20A for 30sec max with reduced accuracy but please... come on 

Quick some details about the casing: There are rubber gaskets all around the case and the battery compartment. The screws which hold the two case parts together have all a metallic and a rubber washer which is quite nice. I need to check how they sealed the range switch which must have been more complicated.

BTW: The photos are intended to have high-res so that you can see all details

[Wytnucls]

I never liked that long wire to the shunt either. Probably works ok, but it looks messy. Seems to be a common feature on that EX series. A thick tinned trace would have been better. Shunt looks weird, but if it works OK, I wouldn't worry about it. Let's hope that the solder blob doesn't fall off with 20A running through it.
This meter should do the job for you and at least you won't cry if it gets stolen.

[retiredcaps]

Today I received the meter and took some pictures of the inside.

Thanks for the pics.  I appreciate it.

Can you also remove the 4 screws on the lcd and post pictures of underneath the lcd?

[Lightages]

I am glad you got one that wasn't put together by a monkey this time. It looks like it should serve your needs quite nicely.