Fluke 15B multimeter, is it safe? - Page 1
Forum section: electronics / testgear

author: gwet
author_rank: Newbie
timestamp: November 21, 2010, 07:10:07 pm
content: I am thinking about buying a Fluke 15B multimeter (link 1,link 2). I am a beginner and it would be my first multimeter btwAt first I was going to buy a very cheap multimeter ($10-$30) but I saw that Fluke.Is it safe? Can I test a car battery or measure mains voltage (230V)? I have readthis review about the Fluke 17Bbut for me it is unclear what can be tested with the multimeter.Any advice would be welcome!

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: November 21, 2010, 09:19:32 pm
content: Why you do not reading the manual of it , at the Fluke web site.And if you still have questions , to openly talk about it here !!

author: gobblegobble
author_rank: Regular Contributor
timestamp: November 21, 2010, 09:52:24 pm
content: Kiriakos apparently haven't done background research and is going by the instict, which I'll have to admit works surprisingly ofter just not now.15B/17B/18B are China-only models and aren't sold anywhere else. Not to mention the box has huge text in it which states "NOT FOR SALE OUTSIDE OF CHINA". Technically no-one is breaking the law since you are buying the meter from china but I wouldn't count on warranty service outside of China. Although if you buy from a reputable reseller you should be able to send it back if problems arise.Facts you should note about the meter before buying to name a few (I was considering buying one myself, and still am).- It's a genuine Fluke, so quality-vice it should be head and shoulders above the cheapest meters- Is is not cat-rated very high: catII 600 volts isn't much to call home about, although quite sufficient for a hobbyist use.- It's not tested by any western third party like UL or such, but does seem to have a Chinese third-party test approval- The accuracy and functions aren't anything to call home about either, albeit probably sufficient for hobbyist use- You can't find a mention about it from anywhere at Fluke's english site and only manuals I've come across are english service manual and chinese user manual (I believe I have a copy of both if anyone needs).- You can buy a brand name product for less at equal specs or better (check Dave's $50 and $100 shootouts)In conclusion: yes it should be safe and yes you should be able to measure mains at the wall outlet and car batteries without risk.

author: saturation
author_rank: Super Contributor
timestamp: November 21, 2010, 09:59:19 pm
content: There is a detailed discussion of the 17B here.About it accuracy:https://www.eevblog.com/forum/index.php?topic=896.msg11445#msg11445The whole thread:https://www.eevblog.com/forum/index.php?topic=896.msg15566#msg15566The review you linked is quite fair, and I agree with the blogs conclusion.It should be adequate for use at most from mains voltagecoming froman electrical socket to plugged in devices and then, battery powered items. I didn't know it was not certified by a well known third party for safety, the safety certification for China is called CCC, so even as a typo this is strange.Note CAT II 600V is the same as CAT III 300V in terms of maximum input voltage and transient protection.[ corrected see discussion above]Have you seen Dave's review of DMM? He tested both $50 and $100 DMM and I agree 100% with his conclusions.http://www.prweb.com/releases/multimeter-review/comparison/prweb4237464.htm

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: November 21, 2010, 10:09:00 pm
content: gobblegobble are you always overreacting , or you do that just for me ?If some one cares to buy the Chinese version of a Fluke , he goes for information at the Chinese site too.Its simple as that .And save all those rants about blaming anything Chinese ..Every one item - multimeter - device - what ever ... gets an evaluation as product.And not because of the flag on it .I hate the flag wars , but if any one start any , I will always support the Chinese side ,just for the fun of it.

author: Unknown
author_rank: Unknown
timestamp: November 21, 2010, 10:19:15 pm
content: Quote from: saturation on November 21, 2010, 09:59:19 pmAssuming it's more than 10m from a CAT III source (eg. service entrance) and more than 20m from a CAT IV source (eg. overhead line).Quote from: saturation on November 21, 2010, 09:59:19 pmWhat about output impedance? It is different between CAT I 1000V and CAT II 600V, so I imagine it might also be different between CAT II 600V and CAT III 300V.

author: gwet
author_rank: Newbie
timestamp: November 21, 2010, 10:33:17 pm
content: Thank you all for your replies!Quote from: gobblegobble on November 21, 2010, 09:52:24 pmYou can find the user's manual in English here:linkQuoteThat's what I wanted to hear!

author: gobblegobble
author_rank: Regular Contributor
timestamp: November 21, 2010, 10:45:04 pm
content: Sorry Kiriakos, nothing personal against you.Quote from: alm on November 21, 2010, 10:19:15 pmI distantly recall reading something similar where the main point was IIRC that the greater CAT rating is actually better despite the lesser voltage.Quote from: gwet on November 21, 2010, 10:33:17 pmWow. Thanks a million!

author: saturation
author_rank: Super Contributor
timestamp: November 21, 2010, 11:22:48 pm
content: Thanks alm for those insights. I'm not aware of the how the first comment you made fits, can you explain?As for the second, you are right, I'm wrong. I went looking for the older table I saw and it includes the effects of impedance.CAT III and IV can be made equivalent for different rated voltage given the transient protection and assumed impedance:For example CAT III 1000v ~ CAT IV 600VBut not between I, II, and III because of varying impedance, here written as test resistance, even for different rated voltages.Quote from: alm on November 21, 2010, 10:19:15 pm

author: Unknown
author_rank: Unknown
timestamp: November 21, 2010, 11:43:07 pm
content: Quote from: saturation on November 21, 2010, 11:22:48 pmA residential wall outlet is CAT II, unless it's close to a CAT III or CAT IV source, in that case it's CAT III or CAT IV. So you can't assume that it's always CAT II. The idea is that the extra wiring adds resistance/inductance, which limits transients. It's not like a meter of wiring between a CAT III source and a wall outlet magically makes it less dangerous.

author: saturation
author_rank: Super Contributor
timestamp: November 21, 2010, 11:48:11 pm
content: Yes, CAT ratings first, before voltage. But if you have access to the full test table, as I referenced you can calculate an equivalent using roughly ohms law.For example, CAT 3 at 1000V, an 8000V transient from 2 ohms delivers 4000A of transient current.Likewise, for CAT IV 600V, 8000V from 2 ohms delivers 4000A too. The spike has the same power.Quote

author: Psi
author_rank: Super Contributor
timestamp: November 22, 2010, 01:38:06 am
content: Only thing that puts me off it is the fact it's not true RMS.

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: November 22, 2010, 10:02:28 am
content: Quote from: Psi on November 22, 2010, 01:38:06 amIf the low priced ones , was TRMS , the expensive ones would never sold..

author: saturation
author_rank: Super Contributor
timestamp: November 22, 2010, 03:23:48 pm
content: Thanks alm, interesting I've never run into this portion of the category, my bad. Found the analysis on Fluke education website. Much thanks.Quote from: alm on November 21, 2010, 11:43:07 pm

author: gwet
author_rank: Newbie
timestamp: December 03, 2010, 10:32:05 pm
content: Today I have received the FLUKE 15B multimeter. Nice design and good quality (solid input jacks!). I bought it from dealexcel for €52.42 (69.99 USD).At first the continuity beep function was working quite bad. I cleaned the probe tips with ethyl alcohol and now it is working reasonably well. The user's manual is in Chinese and English (October 2002 Rev. 4, 1/10, newer thanthis onein PDF format).The multimeter is interesting enough to be reviewed by EEVblog in one of their videos!!! (most basic multimeter from FLUKE).Great multimeter for a beginner, probably better than the Chinese junk I was going to buy... watch this video!:

author: FenderBender
author_rank: Super Contributor
timestamp: September 15, 2011, 10:38:50 pm
content: Quote from: gwet on December 03, 2010, 10:32:05 pmThat's not a fluke meter, just sayin. That's a piece of shit.

author: vk6zgo
author_rank: Super Contributor
timestamp: September 16, 2011, 05:23:41 am
content: I am amazed that the first thing people on this forum want to do when they get a new instrument,is to race out & hang it across the AC mains!Then you get the reaction "EEEK!! Shock,Horror! from the CAT rating devotees.No! No! to read 240v RMS you need to have something rated for 6000v spikes!Most people are unlikely to be messing around on the supply side of the home or work meter box,where the supply impedance is lower,& if you get between phases,you obviously are dealing with higher voltages anyway.What they might do is measure the mains coming into a piece of equipment,or perhaps look at a power point.People have been doing this for many years,way before CAT ratings were even a glint in some bureaucrat's eye,& with proportionally,very few injuries sustained.DMMs are normally handheld,which makes any hazard closer to the body than the heavy old AVOs & Simpsons which were normally placed on a bench,or the floor,so if someone is silly enough to hang the thing across 240v on a current range,there is obviously more chance of injury.Meanwhile,back in the real world,electrical equipment of all kinds are used every day,in the home,& in industry.When was the last time you heard of a lady using a hairdryer or vacuum cleaner having the thing blow up from an 6000v transient?OK,these ratings are a good thing,but they are mainly an exercise in butt-saving on the part of the relevant authorities,rather than a reflection of the real world.VK6ZGO