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View Full Version : smie OT, Fluke DMM gloat gone bad



Mcgyver
09-22-2010, 07:44 AM
I picked up a Fluke 87 IV recently with all the goodies, couple of thermocouplers, clamp on current attachment and a hard case. I didn't pay much as there are problems with it.

I fixed the obvious problem, corroded battery connectors.... but more persist.

Thinking its a Fluke, here we go, I load new batteries in. The screen comes up fine and all functions seem to work, but its is ridiculously slow. Some things like resistance it measures normally but others like DC and capacitance it measures but after say a minute. put the probes on a 5V source and it'll start at say 2.5 volts then start slowly ticking up..after a minute it will be close to 5.

Any guess here? I can't see there being much user serviceable inside. Do I send it in? Could this somehow be calibration or is the unit is pooched. The economics probably makes it sketchy to pay to calibrate let alone repair, but maybe I'm missing something

A dissapointing Fluke gloat gone bad :(

mike4
09-22-2010, 07:49 AM
Try checking the negative terminal connection on the main board ,mine had similar faults and when I checked the connection it had been cracked from the lead pressure in my tool case.
i used lead free solder on mine as it is relatively new.

J Tiers
09-22-2010, 08:26 AM
There is a series protective resistor in-line with the + terminal on many Flukes... it does sometimes just "go bad"..... it causes either a dead meter, or problems similar to yours.

I've had to replace it, in which case I swiped one from a parts donor meter.

As for calibrating, at the old work, the policy was NEVER to calibrate a hand-held..... We did send out the bench meters, but simply checked the hand-helds against the best resolution calibrated bench meters. If bad, we either adjusted them, or out they went for scrap.

ckelloug
09-22-2010, 08:39 AM
I had a fluke 87 III that went bad due to a known manufacturing problem. I sent it in to fluke for calibration which cost about $125 dollars and I got a box back a few days later. Fluke had included a letter in the box stating that their policy of calibration by replacement had caused them to enclose a brand new fluke 87 IV with NIST traceable calibration.

I don't know how Fluke is now but I assume they are still pretty good.

--Cameron

Fasttrack
09-22-2010, 11:48 AM
I'm with JT. I wouldn't bother paying to calibrate a hand-held unit. If you need accuracy, check out ebay for a nice bench top DMM and then get that calibrated. I picked up a 9 digit Keithley with a high current setting (up to 20 amps) for a very reasonable price and had it NIST calibrated for $85.

Hand held meters are sort of like tape measures where a good bench top unit is like a micrometer, imo.

That being said, it may be worth repairing. Sometimes the repair costs are not as extreme as you might expect.

Mcgyver
09-22-2010, 03:32 PM
thanks guys....

Fluke says $95 to calibrate....I think I'll play a little dumb (I heard that!) and just send it in saying it needs calibrating and see what happens. If they send a new meter, problem solved....and I'd have to pay for calibration anyway on a repair

Tom, I recently picked up a Fluke 8840a bench meter for a good price, its $184 to calibrate. I don't need super accuracy for that much, and 8840a seems good for everything, zero volts on a short, agrees my other meter (a greenline) which are my only ways to test...... except resistance where its off 0.2 ohms (using 4 wire). It does have a offset so that can be overcome i guess....still on a meter of that quality with a 4 wire measurement I'd expect it to zero measuring resistance probe to probe.

Do i need much accuracy? No, probably not, maybe for making a shunt for a panel meter or such i might find it useful, but toy collecting is always enough of a excuse, er, reason. There's local guys i can probably go to to get it done cheaper than 184 and then i'd have a great base from which to compare

darryl
09-22-2010, 11:48 PM
What are you going to be using it for? Checking the voltage of a battery? Seeing if there's ac voltage at an outlet?

The best meter to use is one that's findable, actually works, and gives readings appropriate to what you're trying to check.

I don't need no Fluke- I got a bunch of $10 digital meters here, and as long as they work and will measure the parameter I want to check, then the job is done. It's done better than the Fluke could do it, simply because here's one, I pick it up and use it, get the reading, move on. If I lose it or wreck it, there's another meter in the drawer, or in the other room, whatever.

There aren't many people on this forum who need the accuracy and range and features that an expensive meter might provide. There are even less people percentage wise in the rest of the population that would need the sophistication of an expensive meter.

Sorry, I'm not trying to get on anyones case- it's just that I'm not taken in by the 'Fluke is such a great meter' hype. And sending a meter off to be calibrated- how do you know it's going to come back still calibrated? How are you going to know if the readings are absolutely correct anyway?

Although in this case, if it's playing the odds of getting a new replacement meter sent to you instead of the old worn out one back, that's one thing-

J Tiers
09-23-2010, 08:36 AM
What are you going to be using it for? Checking the voltage of a battery? Seeing if there's ac voltage at an outlet?

The best meter to use is one that's findable, actually works, and gives readings appropriate to what you're trying to check.

I don't need no Fluke- I got a bunch of $10 digital meters here, and as long as they work and will measure the parameter I want to check, then the job is done. It's done better than the Fluke could do it, simply because here's one, I pick it up and use it, get the reading, move on. If I lose it or wreck it, there's another meter in the drawer, or in the other room, whatever.

There aren't many people on this forum who need the accuracy and range and features that an expensive meter might provide. There are even less people percentage wise in the rest of the population that would need the sophistication of an expensive meter.

Sorry, I'm not trying to get on anyones case- it's just that I'm not taken in by the 'Fluke is such a great meter' hype. And sending a meter off to be calibrated- how do you know it's going to come back still calibrated? How are you going to know if the readings are absolutely correct anyway?


There ARE some differences....... some BIG differences.

I have seen what a "Beckman" a "Tenma" and a "Fluke" read on the SAME voltage.

Sorry to bust the bubble, Darryl, but the cheap meters may read significantly different from the Fluke, AND from each other on different waveforms.

As for calibration: Calibration tends to stay good despite reasonable abuse. At least with a Fluke meter. Dunno about cheapies..... they are built cheap, and work cheap, cal stays good as well as a $10 meter might be expected to.......... Calibration also offers traceability, and satisfies paperwork requirements, if that is necessary......

And I totally agree that there is no magic timer that causes the meter to read bad at 12:01 AM on the day after the calibration interval expires.... also no "magic shield" that makes it stay good DURING that time.

If a meter is out of cal when calibrated, all readings back to last cal are in doubt. The purpose of calibration is really to VERIFY that the meter IS in calibration..... If it is drifting, and has been OUT, there is a problem that adjusting a "cal pot" is not going to fix.

Fluke isn't what it once was..... I think NEW Fluke ("Fook") QC is negative, non-existent, crap. But the meters, when they actually work, are very nice. And old ones are good, pretty much universally.

It has to do with the design. The actual measuring circuits.

The cheapies use all sorts of variations, apparently, with different responses. You really don't know what you are going to get. Just about any Fluke you pick up is going to give you a usable reading. And even when the Fluke lies, as all meters do, it lies in a consistent way.

It is also rather difficult to kill a Fluke meter. Some of the Beckman, Tenma, whatever, meters are awfully easy to damage.

This all may have changed.... When Fluke ran away to china, the new "Fook" meters started coming in dead, or with bad ranges, or failures that occurred soon after starting use.

And, I don't think the new chinese designers at "Fook" are as good as the US "Fluke" folks used to be.... new "Fook" meters seem to die earlier and easier.

But they still do read and act better than any of the cheapeis I have had the displeasure of using....

ckelloug
09-23-2010, 11:46 AM
If your only use for a multimeter is as a digital battery tester, cheapies are fine. If you're trying to take some kind of actual measurement, a good dmm is important.

I remember in college, we did a lab on meter responses. We were first asked to measure a voltage in a relatively high impedance circuit with a venerable Simpson 350. Then we measured it with a cheapie, and a high quality digital bench meter. For giggles, I brought along my old Fluke 87 II.

The Simpson 350 (afterwords known as the $hitson 350) had so low an impedance as to load the circuit and dramatically change the behavior. We had to do a correction for meter impedance to get the right value. Simpson 350's were good analog meters back in the day but they are low impedance and not very good for diagnosing modern things with tiny currents, low voltages and high impedances.

The cheapie meter did a bit better than the electromechanical Simpson 350 but it still had a low impedance, loaded the circuit and caused substantial error. A meter impedance correction had to be used to get a valid measurement.

The laboratory bench meter and my Fluke 87 both provided an accurate measurement with no impedance correction because they both had impedances of at least 20 megaohms.

Things got worse when we did measurements in an AC circuit. The Simpson 350 was not a true RMS meter and in AC mode was only correctly able to measure the voltage of a purely sinusoidal waveform. The cheapie claimed to be a true RMS meter but it only was true-rms accurate to about 2 kilohertz due to a pretty cheesy phase lock loop. The fluke 87 and the bench meter were both accurately true RMS up to 20kilohertz on any shape waveform our signal generator could dish out.

Bottom line is this. I've seen with my own eyes that a cheapie meter can have a serious deleterious effect on measurements. When used for it's intended purpose, a DBTWOF (Digital Battery Tester With Other Functions), a cheapie meter is OK.

If you need to figure out why the DC gain in your opamp circuit is wrong by measuring voltages in the feedback network, you will see that you get what you pay for in a cheapie meter. If time isn't money and the measurement doesn't matter, a cheapie is good. If you're trying to do real work on a modern electronic object, save the heartache and buy a real meter.

--Cameron

hoof
09-23-2010, 12:30 PM
My two cent's... I use a meter every day. I troubleshoot automated assembly equipment. As for the shop rarely but on occasion I do. The big difference for me between the cheapies and a Fluke is safety. I have a feeling that if a mistake is made with the cheapie the dame thing is going to blow-up in my hand. The Fluke however just give me a funny kind of beeping. I frequetly need to measure 480vac, 575vac, almost 1Kv dc (Use the meter as part of a divider, and up to 10 amps. These meters are the best you can get for the factory floor in my opinion and until a meter comes around with a better reputation I think I will stick with it. So far I have been able to walk out of the building under my own power everyday.:rolleyes:

Ray

Mcgyver
09-23-2010, 12:40 PM
I want a meter that does everything, temp, capacitance etc and is solid and reliable. I want one that's nice to use and will last. I don't spend 500 new, I spend 50 used.....in this case, it not being perfect, is a rare exception in my used quality brand tool buying track record. My Greenlee, also bought for 50 as been outstanding. What budget options would suggest offers more value than that greenlee for 50?

The only reason for not being satisfied there is the Greenlee doesn't do temp. And its being used for more than checking batteries. Do i need that accuracy? Mostly not, maybe sometimes yes....but how many among us can claim to use all of our tools to the max in all of their dimensions?

Another aspect is I just like quality stuff. For many jobs a $10 china mic might be just fine, but I reach for a Starrett or B&W or Etalon or Mitutoyo because its nicer to use. and it'll last. and it'll have value when I'm done...and its reliable.....and I bought it for a China mic price.

Lastly, its all being done fulfilling Maslows highest need, which is what a hobby is, who can say "because i want to" isn't a completely good enough reason?
The pursuit of these quality items at bargain prices represents for me by a wide margin, the best value proposition. yeah this one has some hair (first time), still, I'm in for $50....with a hardcase, two thermo couplers, clamp on attachment.....so i spend another 100, its still great value imo

J Tiers
09-23-2010, 10:31 PM
Oh, Ja..........

I buy all my Fluke stuf used..... I don't LIKE the new "Fook" versions..... and I am good with the old ones. handhelds are 77 and 79. No 87, although I'd not mind the TRMS. Would rather have an older power meter, they give harmonics, TRMS, show the waveform, etc, etc. I have regular use for that.

So far the most I ever paid for a bench meter was $100, and that was for the old 8010. It is at least, portable, battery. The 8000 and 8600A are corded types, and were considerably cheaper.

My big problem now is that I have three bench meters overdue for cal, and my friendly local cal shop (Feitek) folded up a couple years ago when the owner, Bernie, died. Having had stuff fixed or cal'd by the other local guys, I am not impressed....... need a new cal lab.

metalmagpie
09-23-2010, 10:56 PM
I have a dead Fluke 77, battery voltage 8.4, both fuses show continuity. Symptom: I turn it on and nothing happens.

Can one of you geniuses tell me what to try next?

J Tiers
09-23-2010, 10:58 PM
Check battery wires.

Highpower
09-23-2010, 11:09 PM
My big problem now is that I have three bench meters overdue for cal, and my friendly local cal shop (Feitek) folded up a couple years ago when the owner, Bernie, died. Having had stuff fixed or cal'd by the other local guys, I am not impressed....... need a new cal lab.
I've been wondering about this place:

http://www.scherrerinstruments.com/index.html

Any experience with them?

Highpower
09-23-2010, 11:23 PM
I have a dead Fluke 77, battery voltage 8.4, both fuses show continuity. Symptom: I turn it on and nothing happens.

Can one of you geniuses tell me what to try next?

Maybe a clue in here?

http://www.google.com/url?sa=t&source=web&cd=5&sqi=2&ved=0CCIQFjAE&url=http%3A%2F%2Fwww.testequipmentdepot.com%2Ffluk e%2Fpdf%2F77iii.pdf&rct=j&q=fluke%2077%20reset&ei=7RecTJ_EG8WBlAfwh5TXCQ&usg=AFQjCNHuw7gq28F4XuEJBb2XdhVR_YX85Q&cad=rja

darryl
09-24-2010, 01:49 AM
I knew that would get a few people going, though that wasn't my intention. I'm not discounting the value of a good meter, just trying to point out that for most uses it's no more valuable than the $10 special. Another point I would make is that it isn't the absolute value of a voltage or current that's important- it's what the series of tests you're doing using the meter is telling you. Analog meters can outshine digitals in some applications as well- seeing what the needle is doing can tell you more than what the actual readings do. I've been an electronics tech for many decades now, and have been experimenting for longer than that, and seldom have I had the need to get some exact and known-to-be-true reading. Here's something- when I do need to know the precise value of a parameter, I reach for my good analog meter-

To be fair though, I'm not working in a lab, I'm not sharing readings with other people who need to know that my meter and theirs would both read the same- guaranteed in writing, calibrated, dated, signed by a certified employee at a respected company, etc. Where the requirements do exist, by all means use the appropriate tool- if it' a Fluke meter, then so be it.

Of course the other thing is the measurement parameter- if you need it to read frequency, temperature, or act as a curve tracer, etc- well I think most of you know what I'm getting at.

I for one would love to have a scope meter, a handheld o'scope. There's no cheap meter I know of that has that-

Mcgyver
09-24-2010, 08:15 AM
I knew that would get a few people going, though that wasn't my intention.-

hey, I'm not going anywhere, just bantering. In my search for info on this meter I found a post somewhere on a forum where someone with a dozen meters ranging from $10 to the best of the best bench meters made comparative measurements with them all. All with within a fraction of a percent of the same reading - by that metric the logical choice is clear. However its not so clear when you take in the rest of the universe (even that of home shop which excludes all the commercial & collaborative considerations you mentioned). For me the attraction was reliability & longevity (didn't quite work out as planned, but was still a valid 'why') , does it have all the functions, and just plain old how nice is it to use ...all combined with what the good ones can bought for used.

I also like have more than one going while working, one clipped to ground measure voltage and other checking current or resistance etc. Just nicer than flipping back and forth...but that may be a product of where i am on the curve. Someone more experiece may just build knowing whats happening and use the meter to debug/repair. Me, I'm using it non stop a because it helps me see and learn what's going on.

J Tiers
09-24-2010, 08:28 AM
I've been wondering about this place:

http://www.scherrerinstruments.com/index.html

Any experience with them?

Bernie used to work there, he had been the manager before he went off on his own. I actually had thought Scherrer was out of business, but when I went through Maplewood a little while back, I saw their sign. The old man must be gone, No idea how they are now.

I did NOT like "industrial <somethingor other>" that used to be up North (Rock road area??)... they took quite a while to not fix a Philips scope. And the place near Westport took several weeks to "not fix" a spectrum analyzer that Feitek fixed in a few days, for less than the other estimate..... I think their big business is mechanical gages, scales, etc.

ckelloug
09-24-2010, 08:28 AM
I hope I wasn't trying to be too inflammatory discussing the properties of "DBTWOF's". I have a bias towards electronics since I used to be an engineer developing semiconductor wafer test machines. Everything from an led with a resistor connected to it to a Simpson 350 has it's place if you understand what you're measuring and how; it's just that when you don't fully understand, a well designed high impedance meter is less likely to lead you astray.