[MOVED] Fluke 233 - WTF Happened? - Page 1
Forum section: electronics / general

author: Zad
author_rank: Super Contributor
timestamp: December 05, 2010, 04:37:20 am
content: Some of you may recall that I have a Fluke 233 multimeter, that is the one where you can remove the display module to monitor the measurement remotely. It is a pretty decent and robust meter in the Fluke tradition. It takes a total of 5 AA cells, with a quoted lifetime of approximately 400 hours. I have had my 233 just over 4 months, and maybe used it for 5 hours in total, none of which were on standby, or with timeout defeated.I came to use it this evening and this is what met me:What the f%&k? Both sets of batteries well and truly flattened. Brand new Duracell AAs with a shelf life of March 2016. 5 batteries lasting 4 months of light usage? I don't have my old Fluke 77 with me to measure quiescent current, but to flatten those cells in so short a time, something must be wrong. Measuring them off-load, they each gave a consistent 0.95 to 0.96 volts, so it wasn't a matter of an odd cell going high resistance.To potentially use more than 15 batteries a year is ridiculous. I do sometimes not use my meter for a month or so (mostly paper and PC based designing) and in that time it has gone from no indication, to empty. Removing the display causes an error to appear and no measurement is possible. Surely all the cells cannot have been faulty?I will ask for Farnell's (the retailer) comment first, and see what they say, but at the moment it is looking like a design flaw. What springs to mind initially is the infra-red system that the body/head unit use to communicate at short range. There is no electrical connection between the two, so the head must surely be continually monitoring the IR sensor, but that doesn't explain the body power.If there are any Fluke people watching, do you have any comment?Mike

author: the_raptor
author_rank: Regular Contributor
timestamp: December 05, 2010, 06:41:06 am
content: It didn't get left so that one of the buttons got held down (upside down, or a heavy enough object on it) thus preventing auto-power off?I doubt it is a design flaw (it seems too obvious for Fluke), more likely a flaw in your unit.

author: EEVblog
author_rank: Unknown
timestamp: December 05, 2010, 07:30:24 am
content: Sounds like something went horribly wrong.I'm sure someone with a unit can measure the standby battery consumption. Although to do that for the head unit with it in place is a bit hard.Dave.

author: saturation
author_rank: Super Contributor
timestamp: December 05, 2010, 11:19:49 am
content: Since both the head and body are low bat, it suggest neither was truly off, you really need to get another DMM and measure the off current, the on current and when the parts are separated.There is a thread here on the Fluke 85-III about quiescent battery consumption, its clearly a bug. When the unit sleeps its really not; it draws 0.7mA regardless, asleep a working 87V unit draws .1mA or so, and off it does 0.00 uA. Alas, no one seems to know or complain about it, and the III has been out of production for some years.

author: Zad
author_rank: Super Contributor
timestamp: December 05, 2010, 04:05:32 pm
content: My other meters are at work, so I will do some tests when I get in on Monday. For the head unit I will solder a pair of Kynar wires to a small piece of scrap double sided copper clad, that should be small enough to slot in whilst the display is docked. It should prove interesting to see how "off" off actually is. When not in use, it gets stored in the original cardboard box, whichshouldn'thave anything pressing against the buttons, but we shall see.

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: December 05, 2010, 08:27:53 pm
content: Buy an serious battery tester and check the cells ..You are blasting the DMM , by excluding the condition of the batteries !!What if this Duracell thingy , one of the five , has issues as cell ?

author: Zad
author_rank: Super Contributor
timestamp: December 05, 2010, 11:42:18 pm
content: I measured each cell, and each was giving 0.95-96v. 1v per cell is usually regarded as ballpark "flat" so I'm not sure putting them on load is going to achieve much beyond telling me that they are all discharged. If I had them all measuring 1.3v or whatever, then I would stress test them.

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: December 06, 2010, 03:44:00 am
content: Quote from: Zad on December 05, 2010, 11:42:18 pmYes for an single cell , those work as team ... teamwork .. all together ... basket team ... footballPut them back in and forget it ... the battery indicatorusuallyappears when the battery set ,has another 30% life in it.What the users manual tells about it ? is this sign an battery low or battery replace sign ?.

author: EEVblog
author_rank: Unknown
timestamp: December 06, 2010, 04:40:21 am
content: Quote from: Kiriakos-GR on December 06, 2010, 03:44:00 amSame thing. A low battery indicator means replace the batteries, and that's what the manual says.For serious work, you should never use any meter that has a single "low batt" symbol being displayed, as the specs are usually no longer guaranteed. You don't know "how dead" they are, and to what affect it has on the reading.Look at the recent Extech product recall because the meter can mistakenly (and possibly dangerously) display no voltage when the batteries are low.<1V per cell is well and truly flat for any multimeterDave.

author: Time
author_rank: Frequent Contributor
timestamp: December 06, 2010, 04:48:15 am
content: we had a few of these 233s sitting around the lab where I used to work and they were always dead and needing batteries.

author: Mechatrommer
author_rank: Super Contributor
timestamp: December 06, 2010, 12:30:37 pm
content: Quote from: Time on December 06, 2010, 04:48:15 amanother design flaw i think. maybe the Fluke's experienced engineers are dead already. The young players are coming in. My assumption.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: December 06, 2010, 02:41:43 pm
content: Quote from: EEVblog on December 06, 2010, 04:40:21 amLo-bat should ideally be a pre warning that the battery needs replacing soon but it should still be within spec - if the battery is too low for the unit to work to spec it should either just turn off or show a more 'severe' warning.BTW any followup on the Fluke 87 EMC issue?

author: saturation
author_rank: Super Contributor
timestamp: December 06, 2010, 03:27:56 pm
content: Yes, concerning for a device. Would definitely check the on/off current drain, fairly simple to do and revealing.Quote from: shafri on December 06, 2010, 12:30:37 pm

author: Zad
author_rank: Super Contributor
timestamp: December 06, 2010, 07:02:41 pm
content: Okay, here are the results from today's brief investigations.Body power consumption, power ON = 3 to 6mABody power consumption, power OFF = 0.9 to 1.1mADisplay unit, power ON = 3 to 3.6mADisplay unit, power OFF = 1mALooking athttp://www1.duracell.com/oem/Pdf/new/MX1500_US_UL.pdfthe nominal capacity for <5mW drain is 1600 to 2300mAh (to 1 volt).2300mAh at 1mA, is 95.8 days...You will note that an "on" life of 3mA is 766 hours, and 6mA is 383 hours, which averasges close to the specified taget of "around 400 hours". Presuming you use your meter 24 hours a day, and don't actually switch it off...That is with power switched OFF at the rotary switch, and nothing touching any buttons.Next step is to contact Farnell I think, and see if they can get hold of a Fluke rep.Mike

author: Unknown
author_rank: Unknown
timestamp: December 06, 2010, 07:36:37 pm
content: That sounds pretty horrible. I would expect it to use more power because of the remote display feature, but not in power down mode. 1mA + 1mA would even suck for sleep mode, let alone power off.Stupid question: you sure there isn't an extra off button somewhere, like on the display? Like on a desktop computer with the little switch on the back. Any difference with the display unit unplugged? This was with the display unit attached to the body?Dave reviewed this unit, right? Did he measure power draw, and did these measurements agree? That might clear up whether it's a design flaw or defect.

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: December 06, 2010, 08:45:22 pm
content: Quote from: EEVblog on December 06, 2010, 04:40:21 amDave on your next review , test this detail too .... find the minimum voltage that effects the measurement,since the appearance of the battery indicator until the measurement to beactuallyeffected .Usually the low battery condition , effects only the Ohm range , or use to .

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: December 06, 2010, 08:52:31 pm
content: Quote from: mikeselectricstuff on December 06, 2010, 02:41:43 pmNothing from my end .As soon I got the replacement , there was no further communication.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: December 06, 2010, 10:58:51 pm
content: 1mA in 'off' mode is either a fault or absolutely piss-poor design.There is absolutely no excuse for that much draw.

author: saturation
author_rank: Super Contributor
timestamp: December 06, 2010, 11:15:14 pm
content: Thanks, it clearly confirms the current drain. It seems short battery life has been independently reported by at least 2 users.Like the GSM bug of the 87V, eevblog users should bring this up to Fluke directly. With the unit off, I'd expect a unit to have ~ zero current drain. I have 3 Fluke 80s, and I was surprised to see the 85I or III draw either 1 or 0.10 uA, but since that translates to 57 or 570 years before it drains the ~500mAH 9v battery down with a expiration date of only 5 years; not a big deal, but the 87V is 0.00uA when off. At 1mA it will be dead in 20.8 hours or at least monthly.Quote from: Zad on December 06, 2010, 07:02:41 pm

author: EEVblog
author_rank: Unknown
timestamp: December 07, 2010, 04:55:08 am
content: Quote from: alm on December 06, 2010, 07:36:37 pmI don't remember, I'd have to watch it again.I know I didn't test the head unit because it wasn't trivial to do.If I didn't measure the base unit then I either forgot or was lazy.Those figures certainly would have changed my opinion of it.Dave.

author: PetrosA
author_rank: Frequent Contributor
timestamp: December 08, 2010, 03:14:23 am
content: Speaking of "off" buttons, is there one on the display unit or does it have to maintain wireless contact with the base unit non-stop?

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: December 08, 2010, 07:12:26 pm
content: Lots of info on the table , but some how , I can not call this " effect" as major disaster .If some one gets under consideration , that this tool , it was build , by having in mind ,that it will serve at special environmental conditions , and the remote screen it will protect the user,from physically staying next to high temperature sources , or at very dusty environment.The cost of an battery packVSof what this device offers !! ( makes this comparison as an ridicules one)Its good to know , that there is some sort of power leak .But the user who uses daily the instrument , he will not notice this leak as major symptom, so to nag about it.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: December 08, 2010, 08:13:06 pm
content: Quote from: Kiriakos-GR on December 08, 2010, 07:12:26 pmIt's not about cost but useability- pulling a meterout of your bag and finding it dead can be a major PITA.You should expect better for the price you pay from Fluke - there is absolutely no excuse for ruining a product with such poor design.If I bought a meter with 1mA 'off' mode drain I'd send it back as faulty.

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: December 09, 2010, 01:12:40 am
content: Well by defending Fluke , especially meits a bit funny as happening.Even so , this is an prototype DMM , and there is no second anywhere , so to compare it and find out ,if this " issue " ( lets call it issue ), its something that happens at everything that has an removable display !!By comparing this special type of instrument , with the common designed DMM , its possible to be the wrong way to do such comparisons.

author: gwet
author_rank: Newbie
timestamp: December 12, 2010, 08:39:14 pm
content: Uselow self-discharge NiMH batteriesinstead of alkaline batteries.Sanyo Enelooprechargeable batteries are the best (and they were the first available on the market). Sanyo has introduced recently a new Eneloop battery (2500 mAh) for high power consumption devices (like your Fluke 233!):link. Read more about those new batterieshere.Don't waste money on alkaline batteries!

author: Zad
author_rank: Super Contributor
timestamp: December 14, 2010, 05:59:26 am
content: I tried 2700mAh NiMH cells in it when I first saw it was flat. The head unit seems to run ok, but the meter base seems to be no go on 1.2v. Which is strange as it was just managing on 0.96v. I will try it on a freshly charged set.What Fluke should have done, was to fit a rechargeable battery pack or to allow some form of in-meter charging. Or, better still, use a design that doesn't require the head unit to be monitoring the IR sensor all the time. I would love to know why Fluke deem it necessary for the base station to transmit an IR signal when it is supposed to be turned off (I checked this by pointing a webcam at it).I don't buy the excuse it being a prototype product. If it isn't fit for use, then it shouldn't be on sale.

author: saturation
author_rank: Super Contributor
timestamp: December 14, 2010, 01:02:46 pm
content: Putting rechargeables will save you the cost of buying alkaline batteries, but not the inconvenience of constantly changing it. While you can argue about how much power a device consumes when on, there's no reason to leave it on when you aren't using it, and needlessly using up battery power, as in this case with the mA drain being so high.Hopefully a firmware upgrade can fix that, otherwise if you bought it new I'd trade it for another model such as the ruggedized Fluke 28II, as built as it is and as Dave tried to kill it, it will almost certainly outlive its owner.Per Dave's review on the last 23 min onwardhttp://www.eevblog.com/2010/02/28/eevblog-64-fluke-28-series-ii-multimeter-review-teardown/1.7 mA ON, 5 mA in diode test mode12 mA backlit30 mA high backlight50 uA sleep 'off'0.00 uA switched offThis is a great over all desert island, severe condition DMM that will survive ambient conditions a human can survive too.An external charger for batteries can help, but it increases the cost, and the device may have to be fully disabled while charging as it may not be CAT III rated while charging.Quote from: Zad on December 14, 2010, 05:59:26 am

author: johnboxall
author_rank: Unknown
timestamp: December 17, 2010, 11:34:04 am
content: My first set of AA cells lasted around four months as well, plus I use the backlight on the display most of the time. I'll probably get flamed for saying this but I feel that the convenience of the removable display makes up for the battery lifetime.

author: saturation
author_rank: Super Contributor
timestamp: December 17, 2010, 12:43:56 pm
content: I think that is a good trade off.If you use the DMM daily, 1mA off current won't be noticeable, and it would be good to use rechargeable AA instead.Quote from: tronixstuff on December 17, 2010, 11:34:04 am

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: December 18, 2010, 12:59:59 am
content: Quote from: Zad on December 14, 2010, 05:59:26 amNo , what Fluke did , was to inform you , for the battery life estimation ,and you can argue just on that , and if it was honest or not .And in good faith , you can inform them , that in the next model they have to add an extra mechanical switch to control , the IR sensor power status ...And I bet that they will reply , that if you plan to store the meter for long time , you should just remove the batteries from it .And this is an major known rule , for every Soft-On powered device .How many multimeter s called as Soft-On ? Just yours , because it is made so .If you dislike my view , flame me , I can take it ...

author: innov8
author_rank: Newbie
timestamp: September 20, 2013, 02:22:44 pm
content: Apparently it is a known issue, and you may get an updated firmware or other fix from Fluke.Check this out:https://www.element14.com/community/thread/7523