You need at least 4 multimeters? - Page 1
Forum section: electronics / general

author: miceuz
author_rank: Frequent Contributor
timestamp: March 04, 2014, 07:54:19 am
content: Does anyone remember in which episode Dave talks that you need at least 4 multimeters? One my friend just got caught by burden voltage trap, I want to give him some additional food for thought

author: hans
author_rank: Super Contributor
timestamp: March 04, 2014, 09:12:33 am
content: Episode 110, let's design a SMPS @ 31:20It was about the efficiency Dc/Dc converter, so you need input voltage/current and output voltage/current

author: uwezi
author_rank: Unknown
timestamp: March 04, 2014, 12:08:34 pm
content: Quote from: hans on March 04, 2014, 09:12:33 amAnd then you need afifthone when you want to measure something which is inside the circuit, while still monitoring input and output. In other words, you cannot have too many multimeters - because then there is always numbersix, which is currently without battery...

author: dr_p
author_rank: Frequent Contributor
timestamp: March 04, 2014, 12:17:35 pm
content: And you have to like all of them, so you need at least 10 to choose the 6 from.

author: zapta
author_rank: Super Contributor
timestamp: March 04, 2014, 03:32:54 pm
content: Quote from: dr_p on March 04, 2014, 12:17:35 pmAnd then there are the cases when you work on two DC/DC at the same time...I am getting alone with one.Sent from my Nexus 5 using Tapatalk

author: Pillager
author_rank: Unknown
timestamp: March 04, 2014, 05:38:00 pm
content: Quote from: uwezi on March 04, 2014, 12:08:34 pmYes, you can. Fluke has so many they're selling them...

author: Fsck
author_rank: Super Contributor
timestamp: March 04, 2014, 06:02:57 pm
content: Quote from: dr_p on March 04, 2014, 12:17:35 pmoccasionally, you might actually need/want all 10.

author: Jon86
author_rank: Frequent Contributor
timestamp: March 04, 2014, 06:38:48 pm
content: Quote from: Fsck on March 04, 2014, 06:02:57 pmIn what situation?

author: robrenz
author_rank: Super Contributor
timestamp: March 04, 2014, 06:42:43 pm
content: For a post picture in show your multimeters

author: Dave Turner
author_rank: Frequent Contributor
timestamp: March 04, 2014, 07:34:54 pm
content: Don't forget the obligatory analogue meter(s).I wouldn't be without my TMK 500, which is at least 30 years old, replacing another old trusty from the 60s (unfortunately accidentally destroyed by a friend). Yes it has a 'burden' of 30k ohm/VDC, and requires careful thought before choosing the range and interpreting results.Nevertheless analogue meters still have their place as discussed in another thread.

author: Fsck
author_rank: Super Contributor
timestamp: March 04, 2014, 08:24:07 pm
content: Quote from: Jon86 on March 04, 2014, 06:38:48 pmsome kind of electronic function test.something with many sensors.troubleshooting/analyzing a multiple channel power supplythere's a bunch of RF applicationscharacterizing a whole system for repeatabilitythe 3458a feels like the defacto physics research bench DMM. to save money, many labs combine it with a switch system to have multichannel capabilities. which gives you similar capabilities to multiple DMMs: I've seen this more often in SS&CM physics. on the other hand, I've also seen some labs equipped with half racks of 3458's and a high speed switch system for faster acquisition and higher accuracy or to ensure certain sets of measurements are done simultaneously: more common for particle physics.addendum: need for 4 -> it's pretty common to want 2 voltage readings and 2 current readings simultaneously.

author: madshaman
author_rank: Frequent Contributor
timestamp: March 04, 2014, 08:41:13 pm
content: I don't understand how anyone can get by with just four DMMs :-)

author: robrenz
author_rank: Super Contributor
timestamp: March 04, 2014, 08:49:51 pm
content: At least 2 of the 4 must have built in graphing

author: gdewitte
author_rank: Unknown
timestamp: March 04, 2014, 09:05:03 pm
content: You really need an odd number, so they can vote…

author: sacherjj
author_rank: Frequent Contributor
timestamp: March 04, 2014, 09:10:31 pm
content: Quote from: gdewitte on March 04, 2014, 09:05:03 pmIf you have an even number voting, you can cast the last vote towards what direction you "need" the measurement to go.

author: Jon86
author_rank: Frequent Contributor
timestamp: March 04, 2014, 10:52:26 pm
content: I wonder how big the largest collection of multimeters on here is...

author: pickle9000
author_rank: Super Contributor
timestamp: March 04, 2014, 10:56:47 pm
content: Quote from: Jon86 on March 04, 2014, 10:52:26 pmAsk Dave.

author: Astroplio
author_rank: Regular Contributor
timestamp: March 04, 2014, 11:29:12 pm
content: Quote from: sacherjj on March 04, 2014, 09:10:31 pmLOL you guys!

author: babysitter
author_rank: Frequent Contributor
timestamp: March 05, 2014, 08:24:38 pm
content: I would say you need two DMM (for both labs), Computer control (GPIB) and a Multiplexer O0

author: GiskardReventlov
author_rank: Frequent Contributor
timestamp: March 05, 2014, 09:38:56 pm
content: What's the handheld:bench ratio though?

author: Dave
author_rank: Super Contributor
timestamp: March 06, 2014, 02:12:50 am
content: Quote from: GiskardReventlov on March 05, 2014, 09:38:56 pm4:7

author: BMac
author_rank: Contributor
timestamp: March 06, 2014, 01:04:47 pm
content: Really, can you ever have enough test equipment, ooohh wait i see a new shiny piece of test equipment, gotta go!BMac

author: rjk5378
author_rank: Contributor
timestamp: March 06, 2014, 03:08:24 pm
content: You also need experts on this forum and elsewher to opine often about the need for multiple multimeters and other types of equipment. This is useful when one needs to convince the bean counters at work or, as in my case, for the hobbiest to justify yet another expenditure to the spouse! And, in that regard, having lots of test gear on the bench makes it less obvious that I have smuggled in a new addition. I see each and every unit in all its beauty, but my wife just sees a bunch of junk! <g>

author: GiskardReventlov
author_rank: Frequent Contributor
timestamp: March 06, 2014, 11:15:12 pm
content: Quote from: rjk5378 on March 06, 2014, 03:08:24 pmSo true. A variation on this theme is to maintain a certain level of messiness, it's easy to camouflage something new. Don't leave the shipping carton laying around though.

author: BravoV
author_rank: Super Contributor
timestamp: March 07, 2014, 03:57:36 am
content: Once youhave graduated and have enoughin the progress of collecting more and more DMMs, then don't forget the task on getting more ... <gulp> ... bench power supplies !!!Damn .. the curse never ends.

author: linux-works
author_rank: Super Contributor
timestamp: March 16, 2014, 03:46:17 am
content: another vote for some analog meters, too.I am partial to the classic simpson 260. not high Z, but just a classic that every EE should own. when I see one hanging on someone's bench, I know they are fairly good at electronics(either that, or they're as old as the hills, lol)

author: Rutger
author_rank: Regular Contributor
timestamp: March 17, 2014, 08:59:19 pm
content: I don't want to brag, but I have 16 x Fluke 189 and 2 x Fluke 85V sitting on my bench. (The first lot I picked up at an auction and am sellling on ebay!).I will probably end up with 2 of each kind. I love the 189 display and it isn't much larger than the 85V.You can never have too many DMM's.

author: ErikTheNorwegian
author_rank: Frequent Contributor
timestamp: March 17, 2014, 09:49:05 pm
content: I got 3 Fluke 87V , 2 Flukev87V EX, 2 Fluke 8846A , 1 Fluke 8845A, 2 Fluke 123, 1 analog, 1 Keetly 2000, 1Fluke 115, pluss annother 5-10 diffrent ones in diffrent suitcases. Have a broken Fluke 123 in the post from ebay... so how many one needis realy a strange queastin, plenty pluss some more!

author: Wim_L
author_rank: Regular Contributor
timestamp: March 22, 2014, 03:44:49 am
content: A good reason to have some analog meters: if you sometimes need a lot of meters, but not often, an analog one will still work on volts/amps ranges without the batteries. So you can store them empty, without having to worry about batteries leaking after a while.Assuming you can live with their lower input impedance, of course.

author: zapta
author_rank: Super Contributor
timestamp: March 27, 2014, 05:12:02 pm
content: Quote from: robrenz on March 04, 2014, 06:42:43 pmI see a big business opportunity here. Sell mock multimeters that look great in pictures you take. Will be a hit on Kickstarter.