Which multimeter to buy? - Page 1
Forum section: electronics / general

author: x0170
author_rank: Newbie
timestamp: June 16, 2010, 10:42:53 am
content: Hi.I already have a hand-multimeter but this piece of shit only got a usage time of <3h until the batteries are empty. I bought it on ebay because it was the only multimeter that has a 200khz oszilloscope in it and except of the battery problem it is a great product. (voltcraft gdm 704)But now I want a new one. Which would you recommend? My criterias are:-not to expensive <200€ (250$)-R, C, V=~, A=~ measurement-good measurement resolution, perhaps µV and µA if there is a multimeter that is able to do this in this price category-diode tester, accustic sort-circuit measurement-temperature measurement would be nice tooI heard heard of multimeters which can only measure 50Hz/60Hz AC signals, that's not what i need. I need a multimeter that can measure AC signals up to "high" frequencies (just 20MHz or something like that). Perhaps there is one that shows the measured frequency on its display?Thanks so far. Greets.

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: June 16, 2010, 01:57:08 pm
content: Quote from: shafri on June 16, 2010, 01:13:19 pmThis one does .. at the scale of 75 mV , you can see uV in hundreds .And with the Fluke 87-5 , in tens , with one digit more I could possibly see single uV .But who cares about such low voltage ..

author: Unknown
author_rank: Unknown
timestamp: June 16, 2010, 03:40:39 pm
content: Plenty of 5.5+ digit bench DMM's that have a resolution of 1uV or better, although not necessarily the accuracy down to 1uV. Many are available for <$250 used, but usually lack features like temperature and continuity. The Keithley 177 is even called microvolt DMM. It's only 4.5 digit, but the lowest range is 20mV. Your test setup (eg. inductive pickup, thermocouple effects) will get pretty important at those low levels.Many DMM's will go down to the uA range, even hand-helds.

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: June 17, 2010, 12:35:40 am
content: Quote from: shafri on June 16, 2010, 02:43:06 pmThe only thing that I can say , are that I got truly lucky , by getting at 2010 ,an used 80s model , that still was by far, ahead of it "time" ..And as time , we count the completeness about features .If the Uni-T 71 was build at 90s , it would be called as spaceship ..After all this time , with all my multimeters at hand,the only true practical advantages of the Fluke 87-5 against the pack,are the display speed - True RMS - more resolution .

author: EEVblog
author_rank: Unknown
timestamp: June 17, 2010, 12:48:42 am
content: Quote from: x0170 on June 16, 2010, 10:42:53 amAlmost ant decent DMM over the $100 mark will do tall that, except the uV thing (why do you need that?). They all do 0.1uA resolution on current, more for a 4.5digit DMM. You can get 10uV resolution on a 4.5 digit meter on the 200mV range.QuoteYou seem to be confusing frequency measurement and actual signal amplitude measurement. And/or confusing it with an oscilloscope.There are no meters that only read 50/60Hz, they all do at least 400Hz bandwith, and the more expensive ones might do up to say 100KHz. You generally need an oscilloscope to measure higher AC bandwidth than that.Actual frequency measurement is another function entirely, and many meters can do 10's of MHz.Dave.

author: x0170
author_rank: Newbie
timestamp: June 17, 2010, 09:04:22 am
content: Tanks for your answers.I found one that seems quite good:http://www.conrad.de/ce/de/product/123296/VOLTCRAFT-VC920-DMM/SHOP_AREA_17622&promotionareaSearchDetail=005Here is the manual:http://www.produktinfo.conrad.com/datenblaetter/100000-124999/123296-an-01-ml-VOLTCRAFT_VC920_DMM_de_en_fr_nl.pdfWhat do you think about that?

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: June 17, 2010, 09:50:39 am
content: Quote from: shafri on June 17, 2010, 09:35:30 amIt is one Uni-T unit , under the Brand of an Major "electronic devices supplier" in Germany ..Its an Honor for the Uni-T , that their products travels even by that way on the German market !!Only quality items , get as re-branded , at the German market , that has the most regulations world wide about safety and quality , about anything imported ..The price looks a bit high , but still looks good , as the warranty plan will be 2 years minimum.

author: Unknown
author_rank: Unknown
timestamp: June 17, 2010, 10:24:38 am
content: Voltcraft isn't exactly known as a quality brand, their stuff is usually cheap and sort of works... for a while. There are some exceptions, but I wouldn't consider the fact that the product is sold under the Voltcraft brand a sign of good quality.

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: June 17, 2010, 10:37:52 am
content: Quote from: alm on June 17, 2010, 10:24:38 amAre you again speaking about 80s ? if not I demand true examples - proofs ..For the history ... Voltcraft become known to me, by their own High-Tech Nimi chargers ...They had stop doing their own stuff at list for 15 years .Now days (2000 2010) they work as middle man , between East market and Germany.Lots of products , at any price range .... and the specific one , its not cheap either ..I bet that this one , has even better quality of leads at least .Not to say , that the wacky Germans , they ask even more features from the standard model ,so to have an advantage when it will be marketed ..

author: Simon
author_rank: Unknown
timestamp: June 17, 2010, 11:49:24 am
content: If your looking for a good general purpose meter with all the functions you want get an amprobe AM220

author: Unknown
author_rank: Unknown
timestamp: June 17, 2010, 12:17:55 pm
content: Quote from: Kiriakos-GR on June 17, 2010, 10:37:52 amNo, I don't usually talk about the past in present tense.Quote from: Kiriakos-GR on June 17, 2010, 10:37:52 amIn what position are you to make demands? We both express our opinions, no need to fight about it. Mine is based on my own experiences and the experience of various other people I know with Voltcraft equipment, and I have no desire to attempt to convince you of my opinion.

author: saturation
author_rank: Super Contributor
timestamp: June 17, 2010, 04:09:41 pm
content: Don't know them at all but it seems they are mostly distributor and re-brander, and I presume they evaluate their products to meet German safety regulations. So given this, I would presume the Uni-T DMM are treated similarly. Here are samples of their product line other than the DMMs.In the US, sold as the La Crosse chargerwas the B&K Precision model line 1870/5, still sold as brands by RSR, Reed or Lutron

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: June 17, 2010, 07:52:01 pm
content: Quote from: saturation on June 17, 2010, 04:09:41 pmThis one are truly anLa Chinas.. big failure ...I found it marketed under 6 brands , and the unfortunate part , is that it explodes ..Thats why I become true fun of the latestAnsmannchargers, and battery stations & battery testers. ( they do their own R&D and they do the manufacturing in China, but at list they use their own original ideas )Voltcraft had build at the far past one Nimi 4 channel charger with for lines LCD - and processor running linux , able to charge - discharge - running maintenance cycles , with active coolers , with serial port ,With extra supplied software , and the device had a cost as 200 Euros , and the cost of PC software was extra .Shape like a round spaceship .. { True European technology but at a cost }If the modern Voltcraft , has partners like the Uni-T , has nothing to fear at all .They will gain lots of market share, and lots of cash ..

author: saturation
author_rank: Super Contributor
timestamp: June 17, 2010, 08:02:13 pm
content: That's why you still have to be careful about people who simply brand products, you hope they do their work for safety; but the unit that was tested could differ from the production units, as in the case of this La Crosse charger. Since the reported burning of this model charger, I think the problem was fixed.FWIW, there are other makers who do not have such a reputation, it works safely from day #1, and they make, design and sell their own product, such as Maha Powerex c9000, in the USA market.In multimeters, I think my friend, you know what I would sayQuote from: Kiriakos-GR on June 17, 2010, 07:52:01 pm

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: June 17, 2010, 08:40:56 pm
content: Quote from: saturation on June 17, 2010, 08:02:13 pmMy kingdom are truly democratic and Universal ...

author: Mechatrommer
author_rank: Super Contributor
timestamp: June 17, 2010, 08:58:25 pm
content: now everybody's talking even the charger. eventually as i'm typing right now, i have my MAHA maintaining my nearly dead cells. MH-C801D 8 independent cells n lcd 1 hour aa/aaa battery charger. charge soft n rapid, maintenance/discharge-charge cycle. next is my older energizer charger, just finished charging my other batteries. The MAHA one cost less than $100, IIRC.

author: Unknown
author_rank: Unknown
timestamp: June 17, 2010, 10:13:38 pm
content: I like both Maha and Ansmann chargers. The Maha is more fun for the geek in me, since it can display total capacity and has various programs, as opposed to indicating dead/charging/charged. But both seem to charge just fine. The Maha is a bit more picky about dodgy batteries. I chose the Maha over the Lacrosse because of reliability issues at that time (might have been the fire issue).I didn't mean to imply that all Voltcraft products are bad, as usual with these companies that slap their own label on Chinese stuff, it's hit or miss. I'm sure they are lucky part of the time. My experience (and the experiences of other people I know with Voltcraft test equipment) is that it's usually big on shiny features, but not so great for real-world use. For example, a scope that goes down to 2mV/div, but produces so much noise that it's hard to discern any signal at those levels. Might as well not have those low ranges.Another example is a 4-in-1 function generator/frequency counter/power supply/DMM unit that I got cheap used. The function generator is usable, although the pots feel lousy compared to Tek and HP/Agilent stuff. The specified range is 10MHz, but you won't get anything resembling a square or triangular wave anywhere near that frequency. The amplitude varies a lot with frequency. The frequency counter seems fine, but I'm not big on RF, so I rarely need accurate frequency measurement. The power supply is a standard LM723 design, which drifts a lot, and the multi-turn pot skips certain values (I believe I have a hard time setting anything between 1.0V and 1.7V). The cooling is badly thought out: the power supply is cooled by a heat sink on the back of the unit. There's also a loud fan, but that's only to cool the power supply for the frequency counter/function generator. Those can be switched separately, but the fan is always on full power, even when they're switched off. The DMM takes multiple seconds to decide on a value, the continuity test takes like three seconds to decide that I shorted the probes. It has several features like relative measurements, min/max/average and data hold, but the interface is so bad, that I rarely bother to use them. Plus it runs from a 9V battery, even though it's a huge 30lbs unit that's definitely for bench use. This means that I sometimes have to change the battery (on the back behind my other equipment). It should have been line powered like the rest.It's OK for the price, but I wouldn't consider it high quality. They may re-badge some good stuff, but I wouldn't consider the fact that they slapped their name on it a sign of quality.

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: June 17, 2010, 10:49:10 pm
content: alm start thinking by the today status , fresh new products of 2008 - 2010 ...If I was had buy an older Fluke 87 that the fresh 87-5 ,I would had, by far , more reasons to nag for it ..

author: Unknown
author_rank: Unknown
timestamp: June 17, 2010, 11:10:42 pm
content: Actually I don't think the difference between the Fluke 87 and 87-5 is that large, main problem with the original 87 is the LCD reliability issue (which is well documented and easy to fix), no real usability, performance or safety issues as fas as I know.I'm sure not all of the current Voltcraft products are bad, but their certainly don't have a proven track record of good quality either. So if they put their name on something, it's much less convincing than when Agilent does the same. But vendors don't send me free equipment, so I don't really see the point of buying Voltcraft stuff when other alternatives are available. Why buy a Voltcraft DMM instead of a used Fluke or brands like Extech or even directly from Uni-T? Why buy a Voltcraft charger instead of Ansmann or Maha, or just directly from Lacrosse? Conrad often seems to have trouble telling a transistor and toaster apart, so I doubt that you'll get great support.

author: saturation
author_rank: Super Contributor
timestamp: June 18, 2010, 12:44:48 am
content: Since there are 4 older generations of the 87 series, what specific difference you get will differ according to what series. The general specs are nearly identical for over 20 years. I have an 85 series one.At one point, the calibration adjustment became external, while the series one still has screw potsthe older holsters are better, they are all rubber, and the stand has an internal wire frame that can be bent so it acts like a hook to hold onto doors etc.,the series 1 is not officially CAT rated, since it was around before the CAT rating was inventedthe newer LCD are slightly largerolder models have no backlightsthe battery in older seriesand fuse compartment did not have their own external compartments, but werewasstillinside the caseQuote from: alm on June 17, 2010, 11:10:42 pm

author: MrPlacid
author_rank: Frequent Contributor
timestamp: June 18, 2010, 01:19:06 am
content: Quote from: saturation on June 18, 2010, 12:44:48 amIs the 87v the latest model multimeter? The fuse compartment for that unit isn't external. I don't mind the fuse being internal as I hopefully wont be changing it as often as the battery. Hopefully, I won't be changing it at all.

author: saturation
author_rank: Super Contributor
timestamp: June 18, 2010, 02:33:25 am
content: My mistake, you folks are right. I got it confused with the 28II. There is no separate fuse external compartment on the 87V.Quote from: MrPlacid on June 18, 2010, 01:19:06 amQuote from: shafri on June 18, 2010, 01:24:03 am

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: June 18, 2010, 01:10:48 pm
content: The Fluke 87 link , it will refresh the memories ..https://www.eevblog.com/forum/index.php?topic=354.0

author: x0170
author_rank: Newbie
timestamp: June 19, 2010, 01:46:22 pm
content: So I bought the Voltcraft VC 920 and I am quite satisfied with it yet. I still need to test the batterylife but the measurement performance seems to be very good. The only disadvantage I found till now is that it can measure temperature up to 1000°C but the temperature sensor is only heat resistant to 125°C.Is there anyway to get a sensor that can measure higher temperatures? What about compatibility of thouse sensors, how do they work? Can I built one by myself?Don't say that I sould buy an Infrared Thermometer. I already own such a thing but sometimes its better to touch things like chips than aiming on them with a laser beam. Coffee makes my hands shiver so its hard to measure temperatures of tiny chips with this thing.

author: Unknown
author_rank: Unknown
timestamp: June 19, 2010, 02:01:31 pm
content: The temperature sensor is probably a type K thermocouple, check the manual to be sure. Does it have dual banana connectors or the standard thermocouple adapter with two flat pins? Most thermocouples have the latter, but there are adapters or thermocouples with banana jacks (Fluke makes one, I'm sure there are cheaper ones).I think most cheap thermocouple go up to 300 degC or so, but they are available for up to about 1200 degC.

author: Simon
author_rank: Unknown
timestamp: June 19, 2010, 02:04:47 pm
content: what is the whole situation with K sensors and multimeter's, I discovered that the one from my VC99 works fine with our RS thermometer at work. can i buy a standard sensor that will work with any meter ?

author: x0170
author_rank: Newbie
timestamp: June 19, 2010, 03:05:20 pm
content: It's similar to this with two single banana jacks.There is just a 15ohm when I measure the resistance, that is highly temperature addicted. If I calculate the temperature coefficient, I could build something myself by using a ntc/ptc resistor with the same coefficient right?

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: June 19, 2010, 03:56:39 pm
content: Quote from: x0170 on June 19, 2010, 01:46:22 pmRead this ..https://www.eevblog.com/forum/index.php?topic=448.0

author: Unknown
author_rank: Unknown
timestamp: June 19, 2010, 05:41:47 pm
content: That looks like a type K thermocouple, and works via the Seebeck effect. This means that the junction between to different metals will generate a voltage depending on the junction temperature. There are two wires of different metals, and these are welded at the end. This forms the junction. Any metal between the junction and the jacks (eg. plating) will create a new thermocouple, so if there's a temperature gradient, this will cause errors.There are also resistive temperature sensors, these are actually superior, but more expensive. Type K (there's also a type J and a lot of others) is the cheapest and most common thermocouple.

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: June 19, 2010, 06:21:26 pm
content: For any Temp above the 600 Celsius , the solution called IR ...Even if the probe can take the heat , the human body will have issues with the radiated heat.Simple as that.

author: Unknown
author_rank: Unknown
timestamp: June 19, 2010, 06:32:19 pm
content: Depends on the application. If you want to monitor the temperature for some time, or inside box, attaching a sensor is easier than rigging up an IR thermometer. You may not want to hold the wire probe in your hand, but attach it before it heats up or use a different kind of probe. Radiated heat is only an issue if you get really close. Ever stood near a flame (eg. gas stove)? The temperature of the flame is much higher than 600 degC!

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: June 19, 2010, 06:47:47 pm
content: Quote from: alm on June 19, 2010, 06:32:19 pmNext stop = Bolt on probes .. but here we talk about people , who had less experience in everything.Even me, just from ego , I wanted to see if my meter can count 1000 Celsius..But even my own small kitchen goes max to 220 C ..And I never had considered the danger of the radiated heat , until I read something about it.