Beware Digital Test Meters With Low Battery - UK Vintage Radio Repair and Restoration Discussion Forum

HamishBoxer · 24th Jun 2014, 4:04 pm

Re Fluke 75 MK111 which I was using this afternoon with the battery warning on and thoght all was OK. However while resistance readings were fine, the AC coming out of my Variac was reading 50/60 Volts low or more.

Thought very odd as on max it was only 180 Volts whereas normally it is up to 260 Volts ,checked with spare meter and it was all caused by the PP3 battery being down.

One to watch for as not wanting to wind the Ultra 309 that is in for repair up to 260 Volts when the mains tap is set much lower.

Nickthedentist · 24th Jun 2014, 4:26 pm

Very useful.

My Fluke was doing odd things recently too, and that was down to the battery as well.

The trouble is, they're such damn good meters and the batteries need replacing so infrequently, that you get to trust them implicitly.

N.

kalee20 · 24th Jun 2014, 6:22 pm

Useful info, and surprising too - I would have hoped that if the battery was so low as to screw the calibration, that the display would have gone ---- or whatever (1o 8att is do-able with a 7-seg display).

HamishBoxer · 24th Jun 2014, 7:05 pm

No,the display was fine and think it is only the second battery since new many years ago.
It read around 5Volts and just showed the battery symbol in top right corner.

Nickthedentist · 24th Jun 2014, 8:41 pm

Another problem is that the low battery icon is ambiguous. To me, it does not emphasise the "low" bit enough. A picture of a battery with a line or cross through it would be clearer, or better still, the words "low battery"!

pmmunro · 24th Jun 2014, 9:42 pm

From the 1980s when LCDs were still quite new, perhaps no longer acceptable due to political correctness, but clear enough when you realise what it represents. I wonder how it was described on the design specification.

Maybe they considered adding a Replacement Imminent Procedure.

PMM

Sideband · 24th Jun 2014, 10:02 pm

I get some very strange readings when the battery is low on my digital meter. I also have a power meter that reads volts or watts. I left it switched on for days a few weeks ago. It read the mains OK but showed a TV as only drawing 2 watts when everything was working OK! I then noticed the battery symbol flashing for the first time, changed the PP3 and everything was back to normal.

Seems that with most of these meters, not all ranges are affected the same way.

McMurdo · 24th Jun 2014, 10:23 pm

I get caught out with my Beckmann meter. The only low battery warning is the decimal point that flashes rather than being steady. By the time that happens, it's well out of cal.

Herald1360 · 24th Jun 2014, 11:34 pm

Quote:

Originally Posted by pmmunro

From the 1980s when LCDs were still quite new, perhaps no longer acceptable due to political correctness, but clear enough when you realise what it represents.

Ah, another version of the battery in a coffin symbol. (Dead battery). There's one without the + - but with a "pip" on the top of the battery on my AVO B183 LCR meter. It was some years before I realised what it actually was (other than just a peculiar symbol for battery low).

Just went out to the shed to check its model number and noticed I left it on last time I used it. One very dead (not even coffin symbol generating) battery removed. Luckily no leakage.

Nickthedentist · 24th Jun 2014, 11:43 pm

Thanks for the explanation, Chris. It went straight over my head.

Nick.

pmmunro · 25th Jun 2014, 10:49 am

I'm surprised Nick - you're usually one of the first to see these things. I had you in mind when I wrote that. It was late at night though.

PMM.

HamishBoxer · 25th Jun 2014, 11:06 am

One answer, back to the AVO8 at least it only needs a battery for resistance ranges.

Having said that iI do love my Fluke as well and have a very early one here also that is still going strong.

threeseven · 25th Jun 2014, 11:33 am

My mid 90's Avo DMM flashes the whole display when the battery is likely to cause inaccurate readings, I think it also bleeps.

avocollector · 10th Oct 2014, 2:22 pm

Had the interesting experience of 3 DMM going wierd on me recently. Started with an old Fluke reading half the resistance on ohms, then 128 for mains voltage?? so changed battery but still wonky. Picked up an el cheapo and that too was peculiar - way off on ohms and mains voltage. Finally a third meter medium quality also played up. By then I went back to my old Hioki analogue out of desperation - then the next DMM I picked up was fine?? I don't believe in evil spirits but you'ld wonder sometimes!!

24th Jun 2014, 4:04 pm	#1
HamishBoxer Dekatron Join Date: Aug 2007 Location: W.Butterwick, near Doncaster UK. Posts: 8,932	Beware Digital Test Meters With Low Battery Re Fluke 75 MK111 which I was using this afternoon with the battery warning on and thoght all was OK. However while resistance readings were fine, the AC coming out of my Variac was reading 50/60 Volts low or more. Thought very odd as on max it was only 180 Volts whereas normally it is up to 260 Volts ,checked with spare meter and it was all caused by the PP3 battery being down. One to watch for as not wanting to wind the Ultra 309 that is in for repair up to 260 Volts when the mains tap is set much lower. __________________ G8JET BVWS Archivist and Member V.M.A.R.S

24th Jun 2014, 4:26 pm	#2
Nickthedentist Dekatron Join Date: Jan 2005 Location: Oxford, UK. Posts: 17,843	Re: Beware Digital Test Meters With Low Battery Very useful. My Fluke was doing odd things recently too, and that was down to the battery as well. The trouble is, they're such damn good meters and the batteries need replacing so infrequently, that you get to trust them implicitly. N.

24th Jun 2014, 6:22 pm	#3
kalee20 Dekatron Join Date: Feb 2007 Location: Lynton, N. Devon, UK. Posts: 7,079	Re: Beware Digital Test Meters With Low Battery Useful info, and surprising too - I would have hoped that if the battery was so low as to screw the calibration, that the display would have gone ---- or whatever (1o 8att is do-able with a 7-seg display).

24th Jun 2014, 7:05 pm	#4
HamishBoxer Dekatron Join Date: Aug 2007 Location: W.Butterwick, near Doncaster UK. Posts: 8,932	Re: Beware Digital Test Meters With Low Battery No,the display was fine and think it is only the second battery since new many years ago. It read around 5Volts and just showed the battery symbol in top right corner. __________________ G8JET BVWS Archivist and Member V.M.A.R.S

24th Jun 2014, 8:41 pm	#5
Nickthedentist Dekatron Join Date: Jan 2005 Location: Oxford, UK. Posts: 17,843	Re: Beware Digital Test Meters With Low Battery Another problem is that the low battery icon is ambiguous. To me, it does not emphasise the "low" bit enough. A picture of a battery with a line or cross through it would be clearer, or better still, the words "low battery"!

24th Jun 2014, 10:02 pm	#7
Sideband Dekatron Join Date: Oct 2003 Location: Croydon, Surrey, UK. Posts: 7,567	Re: Beware Digital Test Meters With Low Battery I get some very strange readings when the battery is low on my digital meter. I also have a power meter that reads volts or watts. I left it switched on for days a few weeks ago. It read the mains OK but showed a TV as only drawing 2 watts when everything was working OK! I then noticed the battery symbol flashing for the first time, changed the PP3 and everything was back to normal. Seems that with most of these meters, not all ranges are affected the same way. __________________ There are lots of brilliant keyboard players and then there is Rick Wakeman.....

24th Jun 2014, 10:23 pm	#8
McMurdo Dekatron Join Date: Jun 2009 Location: Staffordshire Moorlands, UK. Posts: 5,270	Re: Beware Digital Test Meters With Low Battery I get caught out with my Beckmann meter. The only low battery warning is the decimal point that flashes rather than being steady. By the time that happens, it's well out of cal. __________________ Kevin

24th Jun 2014, 11:43 pm	#10
Nickthedentist Dekatron Join Date: Jan 2005 Location: Oxford, UK. Posts: 17,843	Re: Beware Digital Test Meters With Low Battery Thanks for the explanation, Chris. It went straight over my head. Nick.

25th Jun 2014, 10:49 am	#11
pmmunro Octode Join Date: Jul 2004 Location: Dundee, UK. Posts: 1,813	Re: Beware Digital Test Meters With Low Battery I'm surprised Nick - you're usually one of the first to see these things. I had you in mind when I wrote that. It was late at night though. PMM.

25th Jun 2014, 11:06 am	#12
HamishBoxer Dekatron Join Date: Aug 2007 Location: W.Butterwick, near Doncaster UK. Posts: 8,932	Re: Beware Digital Test Meters With Low Battery One answer, back to the AVO8 at least it only needs a battery for resistance ranges. Having said that iI do love my Fluke as well and have a very early one here also that is still going strong. __________________ G8JET BVWS Archivist and Member V.M.A.R.S

25th Jun 2014, 11:33 am	#13
threeseven Octode Join Date: May 2010 Location: Worcestershire, UK. Posts: 1,880	Re: Beware Digital Test Meters With Low Battery My mid 90's Avo DMM flashes the whole display when the battery is likely to cause inaccurate readings, I think it also bleeps. __________________ BVWS member

10th Oct 2014, 2:22 pm	#14
avocollector Heptode Join Date: Jul 2010 Location: Wellington, New Zealand. Posts: 653	Re: Beware Digital Test Meters With Low Battery Had the interesting experience of 3 DMM going wierd on me recently. Started with an old Fluke reading half the resistance on ohms, then 128 for mains voltage?? so changed battery but still wonky. Picked up an el cheapo and that too was peculiar - way off on ohms and mains voltage. Finally a third meter medium quality also played up. By then I went back to my old Hioki analogue out of desperation - then the next DMM I picked up was fine?? I don't believe in evil spirits but you'ld wonder sometimes!!