Fluke 87V shows -OL when in ohms range - normal or not? - Page 1
Forum section: electronics / beginners

author: evava
author_rank: Regular Contributor
timestamp: July 19, 2019, 08:21:11 am
content: I want to ask more experienced people:Is it normal to see "-OL" (minus sign) on display F87V when in ohms range, or does it indicate issue with this meter?I see that in advertisement picture, I have not the meter in my hand.

author: MarkF
author_rank: Super Contributor
timestamp: July 19, 2019, 08:50:36 am
content: Both of my Fluke meters show "0L" without leads connected. Neither have the (-) minus sign.I don't know if that indicates a problem. It might just be a slight calibration offset.

author: Brumby
author_rank: Unknown
timestamp: July 19, 2019, 10:33:15 am
content: You can expect this sort of behaviour on every DMM when the resistance between the terminals is higher than can be measured on the range selected. If in autoranging mode, the resistance is higher than the meter can measure.You should always get this when there are no leads plugged in - which is the case in this photo (If it DIDN'T show -OL, then itwillhave a problem!) - or when the leadsareplugged in but the probes are not connected to anything.If you get this when a resistance being measurediswithin range, then you might need to check for an open circuit. (Meter leads are not infallible.)

author: exe
author_rank: Unknown
timestamp: July 19, 2019, 10:44:16 am
content: Bramby, that was my initial answer too (I deleted it), until I re-read the topic. The question is not about OL indication, the question is why it is negative.

author: evava
author_rank: Regular Contributor
timestamp: July 19, 2019, 10:52:48 am
content: Just that, it shows "-OL" (minus sign) when there are no leads plugged in (according to photo) , so you think this is not OK?I think it is suspicious at least, that's why I ask.

author: Brumby
author_rank: Unknown
timestamp: July 19, 2019, 11:26:24 am
content: I'll just step back into the shadows and let someonewithan 87V comment.

author: HighVoltage
author_rank: Super Contributor
timestamp: July 19, 2019, 11:33:25 am
content: My relatively new 87V does NOT show a minus sign!

author: MarkF
author_rank: Super Contributor
timestamp: July 19, 2019, 01:33:20 pm
content: Quote from: MarkF on July 19, 2019, 08:50:36 amI forgot to mention- I have a Fluke 117 and a Fluke 87V.

author: Shock
author_rank: Super Contributor
timestamp: July 21, 2019, 08:07:07 am
content: My meters don't show this but I have a feeling I've seen it somewhere before, I've worked on many.Assuming it's not a stuck segment, I suspect that its either an input protection problem, calibration, or current leaking somewhere on the PCB. Might even be battery related, I would treat it as a potential problem and if buying ensure it zeros out on all measurement ranges with leads if possible.

author: Dabbot
author_rank: Regular Contributor
timestamp: July 21, 2019, 09:38:48 am
content: My 87V does NOT show the minus sign on ohms range.Firmware version: 3.03

author: Wimberleytech
author_rank: Super Contributor
timestamp: July 22, 2019, 02:44:15 am
content: My 87V does not show the minus sign either.

author: alsetalokin4017
author_rank: Super Contributor
timestamp: July 22, 2019, 03:44:08 am
content: 87 III -> no.83 -> no.I can't tell you how happy this makes me. I literally do not know what I would do if a minus sign showed up in this specific instance, without any other symptoms.

author: evava
author_rank: Regular Contributor
timestamp: July 22, 2019, 07:20:31 am
content: Thank you.I am sure now it is potential problem.

author: Dabbot
author_rank: Regular Contributor
timestamp: July 22, 2019, 07:52:12 am
content: I wonder if joeqsmith has seen something like this throughout his DMM transient tests.

author: Electro Detective
author_rank: Super Contributor
timestamp: July 22, 2019, 09:36:01 am
content: Quote from: Dabbot on July 22, 2019, 07:52:12 amIt's a sure bet none of those meters were sporting a 'LOL' reading after getting transienated by Mr. SmithOP evava : I just had a go at both 87V and 28-11, with nothing plugged in,and no '-OL' on the display, and I tried hard to make it happeni.e. it's looking a bit suss, don't buy itNegative Parallel Universe Import?

author: exe
author_rank: Unknown
timestamp: July 22, 2019, 09:42:21 am
content: Quote from: Electro Detective on July 22, 2019, 09:36:01 amon the other hand, it's an opportunity to ask for a discount and have fun with repairing it

author: Electro Detective
author_rank: Super Contributor
timestamp: July 22, 2019, 09:47:22 am
content: Quote from: exe on July 22, 2019, 09:42:21 amI'm with you therebut may be pushing the luck getting fixit docs from Fluke for an issue like thisThen again, a simple CAL might sort it out

author: vinyl
author_rank: Newbie
timestamp: August 07, 2019, 11:04:53 pm
content: My 28II show OL, but sometimes the minus sign appears and disappears immediately.

author: Brumby
author_rank: Unknown
timestamp: August 08, 2019, 01:50:01 am
content: Quote from: exe on July 22, 2019, 09:42:21 am... If, in fact, it needs repair.I keep wondering if it is just aslightbias that the ADC registers as negative. With an input around zero, it would only take a poofteenth of nothing (in the wrong direction) to be classified as "negative".This is just a thought - and I cannot discount the possibility that this is indicative of a real problem - but I'd be tempted to get my hands on it and do some side-by-side comparison measurements with a known good meter. I suspect it could function within specification (assuming no other faults).

author: vinyl
author_rank: Newbie
timestamp: August 08, 2019, 04:01:59 am
content: My 28II ohm auto range (60 mega ohm) momentarily shows a minus sign and disappears soon. Manual range 60Mega is the same.manual range (6 mega ohm --- 600 ohms), OL is always displayed.