Not all meters are created equal - Page 1
Forum section: electronics / general

author: armandas
author_rank: Frequent Contributor
timestamp: June 05, 2010, 12:08:06 pm
content: Just got this tiny multimeter of ebay and.. I love it! It makes me smile whenever I pick it up, really funny thing.Here is a fun fact: the probe leads are rated (105 C, 600V, 24AWG) whereas Fluke probes do not have any info printed on them

author: saturation
author_rank: Super Contributor
timestamp: June 05, 2010, 12:46:07 pm
content: Congratulations. Why not test it for us against your Fluke? Compare accuracy, precision, and its other specs. You can tell then for sure if its capability is true to its published spec or if being small is really all its prime feature is.I've had this Radio Shack DMM for a while, its 'rugged' and pocket-able for field use in a very abusive environment: water filled cave sites.I just recalibrated it against my Fluke 87, as I noticed it was fairly off by a consistent amount for any range. Better now, but testing all ranges to near extremes its no where close to the Fluke. Its great for trending and especially in DCV, but not for accuracy against a standard.

author: armandas
author_rank: Frequent Contributor
timestamp: June 05, 2010, 02:27:44 pm
content: If we take Fluke as a reference, the pocket meter is within the specs (2.5%, but usually better) on most ranges.Square wave generator is supposed to output 3Vpp 50Hz, but gives something like 3.7Vpp 60HzBut yeah, the main feature is the size.

author: Unknown
author_rank: Unknown
timestamp: June 05, 2010, 03:01:01 pm
content: Not sure what the deal is with the printing on the wires. As long as you trust the manufacturer's rating of the complete probe, you should trust that the individual components match those specs. If you don't trust the manufacturer's rating, don't buy their stuff. There's plenty of ways to screw-up you can't easily test, so you better trust them to do a good job. Nothing wrong with verifying the manufacturer's claims, but insisting that it's somehow an important feature seems silly.

author: armandas
author_rank: Frequent Contributor
timestamp: June 05, 2010, 03:22:36 pm
content: Quote from: shafri on June 05, 2010, 02:29:44 pmI wanted to have a pocket meter. Also, it was less than £5.Quote from: alm on June 05, 2010, 03:01:01 pmExactly.

author: Simon
author_rank: Unknown
timestamp: June 05, 2010, 05:32:39 pm
content: Quote from: armandas on June 05, 2010, 12:08:06 pmI have one of those too, probably not the worlds best but it takes that place Dave once talked about where you have a small basic meter to throw in your screw driver box or car tools and drag it around everywhere "just in case"

author: squeezee
author_rank: Contributor
timestamp: June 06, 2010, 09:20:39 am
content: Quote from: saturation on June 05, 2010, 12:46:07 pmI just gave away one of those meters last week, it'd been kicking around the house for at least a decade.When i was checking it before giving it a way i was surprised to find it has a fast, latching, continuity test.

author: saturation
author_rank: Super Contributor
timestamp: June 06, 2010, 02:09:50 pm
content: Its no longer sold by Radio Shack but its a Sanwa branded pocket DMM sold in Asia. FWIW, the DC volts is pretty accurate, after calibration it tracks to 50 DCV its spot on; but many cheapo DMMs are as so, so many Chinese cheapos can do decent work if you stay away from its weakness,which should be known; ohms is OK, ACV useless above 600 Hz, and very susceptible to non-sine wave errors.I use it on field trips and boats with 100% humidity and often over 120F ambient, often its in a dry bag, dropped many times mostly on dirt, grass and concrete, so it has proven it can take some abuse and survive. Because the DMM is small, it has less mass, so the drops are inherently less likely to shatter something; I don't think it was ever tested to be 'rugged'. The molded rubber case does help quite a bit in repelling spray, water, coke and wineInside its all SMT, tight and good construction. It has a insulated foil shield a top the circuitry. It has Radio Shack on the PCB, the only movable item in it is single variable pot. I still use it with its original watch batteries, now near 8 years old. There are no soldering touch ups, cut traces and the like.Its an example of the internal guts looking as good as the external casing, so there was some care in it overall make. In contrast, see the Uni-T model thread, which makes you think what else can they overlook.https://www.eevblog.com/forum/index.php?topic=533.msg7664;topicseen#quickreplyQuote from: squeezee on June 06, 2010, 09:20:39 am