Groups > sci.electronics.equipment > #448

Re: Error of % + digits?

From	"Commander Kinsey" <CFKinsey@military.org.jp>
Newsgroups	sci.electronics.equipment, sci.electronics.basics
Subject	Re: Error of % + digits?
Date	2020-07-16 18:51 +0100
Organization	X
Message-ID	<op.0nuzwne1wdg98l@glass> (permalink)
References	(3 earlier) <rd0bnc$r7s$2@dont-email.me> <op.0mzyrx0owdg98l@glass> <rdecuc$m73$1@reader1.panix.com> <MPG.39651fb94464df2c989f3d@news.east.earthlink.net> <rdjsa6$28b$1@reader1.panix.com>

Cross-posted to 2 groups.

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On Thu, 02 Jul 2020 06:45:42 +0100, Cydrome Leader <presence@mungepanix.com> wrote:

> In sci.electronics.equipment Ralph Mowery <rmowery28146@earthlink.net> wrote:
>> In article <rdecuc$m73$1@reader1.panix.com>, presence@MUNGEpanix.com
>> says...
>>>
>>> > So should I assume the cheaper ones are lying?  Or have they just made a rough estimate adding the two errors?
>>>
>>> might be both. I dug out my first DMM, a Wavetek DM2, circa 1990s. It might
>>> have been from a raffle or something like that.
>>>
>>> The DC voltage specs range from 0.8% +1 digit (not bad really)  over to the
>>> AC ranges which are "1.2% RDG +10 Digits". If I had new leads, I'd trust it
>>> with outlet voltage, but would stay away from 208volts. The meter has 3.5
>>> digits or max display of 1999. I'm figuring a real 100volt AC reading could
>>> be 99 to 101 plus another error of +/- 1 volt for the 10 digits tolerance
>>> on the display or count. so 100volts from your Japanese outlet reference
>>> might read 98 to 102 volts. So while in the ballpark, it's better than you
>>> can read off a Simpson 260 meter in the AC voltage range. I could be wrong
>>> on this too.
>>>
>>> It's a pretty decent meter for poking at DC circuits for the tens of
>>> dollars is must have cost when new.
>>>
>>>
>>
>> It seems that maybe due to modern manufactoring the meters are more
>> accurate than they were 20 years ago.  I bought some DC voltmeters from
>> China.  They display 3 digits.  They read from 0 to 99.9 volts.  I coulg
>> get 4 of them for less than $ 15 including the shipping.  I hooked all 4
>> of them in parallel with a Fluke 87 .  Three of them tracked right along
>> with the Fluke with the last digit sometimes being one high or low from
>> 0 to 24 volts.  The fourth one was off by an average of 2 on the last
>> digit.  I found an adjustment screw on the back of the meter and tweaked
>> it and re ran the test.  It then fell in line with the other meters.
>
> Have you run this test with AC? That seems to be where the wheels come
> off. I brought up this thread to a friend and he mentioned his quest to
> repair some sort of HP true RMS meter that uses a thermocouple and heater
> to properly measure complex waveforms. I can't even guess how slow such a
> meter might be.

How well do these things work measuring dodgy waves like from a cheap UPS or invertor?

>> I had 3 or 4 of the Harbor Freight 'free' multimeters.  The ones that
>> usually sell for around $ 5.  They seem to be reasonable accurate for
>> the money.  Plenty accurate for the home user to test things around the
>> house.  I do admit that the safety issue of putting them across the 120
>> or 240 volt power wires is somewhat doubtful.  I sure would not use one
>> where I worked to put across the 480 volt 3 phase system that is  fused
>> with 200 amps.
>
> I'm pretty timid with anything upstream from a plain outlet.

I've replaced outlets (240V, not the namby pamby USA stuff) without turning off the power - other outlets on the same circuit were being used in the office and I saw no point in interrupting them.

Just keep your fingers off the metal things and don't short stuff together.  Wear goggles and gloves if you want to be a girl about it.

> I had an
> edison base fuse burst in my hand once. Never seen one come apart before.
> It was just a 120v lighting circuit, but right off the service panel.
> There's way more excitement near those things.

Try shorting two phases together with 500A cables.  That causes lots of smoke, a fire alarm, 3 fire engines, and a visit from the power company.  Do not ever employ Irish electricians.

Thread

Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-06-18 14:03 +0100
  Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-06-18 14:28 +0100
  Re: Error of % + digits? Pimpom <nobody@nowhere.com> - 2020-06-18 20:08 +0530
    Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-06-18 15:41 +0100
      Re: Error of % + digits? Ralph Mowery <rmowery28146@earthlink.net> - 2020-06-18 18:16 -0400
        Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-06-18 23:48 +0100
          Re: Error of % + digits? Ralph Mowery <rmowery28146@earthlink.net> - 2020-06-18 19:38 -0400
            Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-06-19 21:46 +0100
              Re: Error of % + digits? Ralph Mowery <rmowery28146@earthlink.net> - 2020-06-19 18:55 -0400
                Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-06-19 23:59 +0100
                Re: Error of % + digits? Pimpom <nobody@nowhere.com> - 2020-06-20 12:09 +0530
                Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-06-20 13:03 +0100
                Re: Error of % + digits? Ralph Mowery <rmowery28146@earthlink.net> - 2020-06-20 11:24 -0400
                Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-06-20 16:58 +0100
                Re: Error of % + digits? Pimpom <nobody@nowhere.com> - 2020-06-20 23:28 +0530
                Re: Error of % + digits? Ralph Mowery <rmowery28146@earthlink.net> - 2020-06-20 14:15 -0400
                Re: Error of % + digits? Tom Gardner <spamjunk@blueyonder.co.uk> - 2020-06-20 23:54 +0100
                Re: Error of % + digits? Cydrome Leader <presence@MUNGEpanix.com> - 2020-06-26 05:10 +0000
                Re: Error of % + digits? Ralph Mowery <rmowery28146@earthlink.net> - 2020-06-26 11:27 -0400
                Re: Error of % + digits? Cydrome Leader <presence@MUNGEpanix.com> - 2020-06-27 06:40 +0000
                Re: Error of % + digits? Ralph Mowery <rmowery28146@earthlink.net> - 2020-06-27 09:55 -0400
                Re: Error of % + digits? Cydrome Leader <presence@MUNGEpanix.com> - 2020-06-29 02:59 +0000
                Re: Error of % + digits? Ralph Mowery <rmowery28146@earthlink.net> - 2020-06-29 10:54 -0400
                Re: Error of % + digits? Cydrome Leader <presence@MUNGEpanix.com> - 2020-06-30 03:28 +0000
                Re: Error of % + digits? Jeroen Belleman <jeroen@nospam.please> - 2020-06-20 20:18 +0200
                Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-06-24 18:37 +0100
                Re: Error of % + digits? Cydrome Leader <presence@MUNGEpanix.com> - 2020-06-26 04:54 +0000
                Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-11 21:38 +0100
                Re: Error of % + digits? Cydrome Leader <presence@MUNGEpanix.com> - 2020-07-13 03:21 +0000
                Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-13 13:32 +0100
                Re: Error of % + digits? Cydrome Leader <presence@MUNGEpanix.com> - 2020-06-26 04:23 +0000
                Re: Error of % + digits? Pimpom <nobody@nowhere.com> - 2020-06-26 14:02 +0530
                Re: Error of % + digits? Cydrome Leader <presence@MUNGEpanix.com> - 2020-06-27 06:56 +0000
                Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-12 18:45 +0100
                Re: Error of % + digits? Pimpom <nobody@nowhere.com> - 2020-07-12 23:31 +0530
                Re: Error of % + digits? Tom Gardner <spamjunk@blueyonder.co.uk> - 2020-07-12 20:21 +0100
                Re: Error of % + digits? Pimpom <nobody@nowhere.com> - 2020-07-13 10:23 +0530
                Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-13 13:36 +0100
                Re: Error of % + digits? Pimpom <nobody@nowhere.com> - 2020-07-13 20:57 +0530
                Re: Error of % + digits? Jeroen Belleman <jeroen@nospam.please> - 2020-07-13 17:39 +0200
                Re: Error of % + digits? Tom Gardner <spamjunk@blueyonder.co.uk> - 2020-07-13 21:04 +0100
                Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-20 21:35 +0100
                Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-20 21:36 +0100
                Re: Error of % + digits? Pimpom <nobody@nowhere.com> - 2020-07-21 12:05 +0530
                Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-31 23:53 +0100
                Re: Error of % + digits? Pimpom <nobody@nowhere.com> - 2020-08-01 14:31 +0530
                Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-13 13:35 +0100
                Re: Error of % + digits? Cydrome Leader <presence@MUNGEpanix.com> - 2020-07-16 07:30 +0000
                Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-17 00:19 +0100
                Re: Error of % + digits? Cydrome Leader <presence@MUNGEpanix.com> - 2020-07-21 01:13 +0000
                Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-08-04 22:27 +0100
                Re: Error of % + digits? Cydrome Leader <presence@MUNGEpanix.com> - 2020-09-09 07:39 +0000
                Re: Error of % + digits? Jasen Betts <jasen@xnet.co.nz> - 2020-07-17 12:15 +0000
                Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-28 19:02 +0100
                Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-13 13:38 +0100
      Re: Error of % + digits? Rich <rich@example.invalid> - 2020-06-24 20:06 +0000
        Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-06-30 00:41 +0100
          Re: Error of % + digits? Cydrome Leader <presence@MUNGEpanix.com> - 2020-06-30 03:52 +0000
            Re: Error of % + digits? Ralph Mowery <rmowery28146@earthlink.net> - 2020-06-30 11:09 -0400
              Re: Error of % + digits? Cydrome Leader <presence@MUNGEpanix.com> - 2020-07-02 05:45 +0000
                Re: Error of % + digits? Jasen Betts <jasen@xnet.co.nz> - 2020-07-02 07:03 +0000
                Re: Error of % + digits? Ralph Mowery <rmowery28146@earthlink.net> - 2020-07-02 10:41 -0400
                Re: Error of % + digits? RheillyPhoull <Rheilly@bigslong.com> - 2020-07-03 09:20 +0800
                Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-16 20:09 +0100
                Re: Separate amps jacks on multimeters Rich <rich@example.invalid> - 2020-07-17 14:02 +0000
                Re: Separate amps jacks on multimeters "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-17 19:16 +0100
                Re: Separate amps jacks on multimeters Rich <rich@example.invalid> - 2020-07-17 20:26 +0000
                Re: Separate amps jacks on multimeters "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-17 21:44 +0100
                Re: Separate amps jacks on multimeters Rich <rich@example.invalid> - 2020-07-17 22:37 +0000
                Re: Separate amps jacks on multimeters "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-18 00:11 +0100
                Re: Separate amps jacks on multimeters Ralph Mowery <rmowery28146@earthlink.net> - 2020-07-17 18:07 -0400
                Re: Separate amps jacks on multimeters "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-17 23:31 +0100
                Re: Separate amps jacks on multimeters Ralph Mowery <rmowery28146@earthlink.net> - 2020-07-17 19:10 -0400
                Re: Separate amps jacks on multimeters "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-18 00:18 +0100
                Re: Separate amps jacks on multimeters Ralph Mowery <rmowery28146@earthlink.net> - 2020-07-17 19:30 -0400
                Re: Separate amps jacks on multimeters "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-28 22:16 +0100
                Re: Separate amps jacks on multimeters Cydrome Leader <presence@MUNGEpanix.com> - 2020-07-22 04:24 +0000
                Re: Separate amps jacks on multimeters Ralph Mowery <rmowery28146@earthlink.net> - 2020-07-22 12:28 -0400
                Re: Separate amps jacks on multimeters Ralph Mowery <rmowery28146@earthlink.net> - 2020-07-17 19:25 -0400
                Re: Separate amps jacks on multimeters Cydrome Leader <presence@MUNGEpanix.com> - 2020-07-22 04:20 +0000
                Re: Separate amps jacks on multimeters Ralph Mowery <rmowery28146@earthlink.net> - 2020-07-22 12:23 -0400
                Re: Error of % + digits? Jasen Betts <jasen@xnet.co.nz> - 2020-07-03 13:10 +0000
                Re: Error of % + digits? Ralph Mowery <rmowery28146@earthlink.net> - 2020-07-03 10:14 -0400
                Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-16 20:10 +0100
                Re: Error of % + digits? Ralph Mowery <rmowery28146@earthlink.net> - 2020-07-16 16:03 -0400
                Re: Error of % + digits? Michael Terrell <terrell.michael.a@gmail.com> - 2020-07-16 13:13 -0700
                Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-17 00:02 +0100
                Re: Error of % + digits? Ralph Mowery <rmowery28146@earthlink.net> - 2020-07-16 23:29 -0400
                Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-24 22:09 +0100
                Re: Error of % + digits? Rich <rich@example.invalid> - 2020-07-24 22:58 +0000
                Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-25 00:31 +0100
                Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-17 00:01 +0100
                Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-16 18:51 +0100
                Re: Error of % + digits? Cydrome Leader <presence@MUNGEpanix.com> - 2020-07-26 03:53 +0000
              Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-16 18:45 +0100
                Re: Error of % + digits? Ralph Mowery <rmowery28146@earthlink.net> - 2020-07-16 15:53 -0400
            Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-16 18:46 +0100
              Re: Error of % + digits? Michael Terrell <terrell.michael.a@gmail.com> - 2020-07-16 10:54 -0700
                Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-17 00:15 +0100
              Re: Error of % + digits? Cydrome Leader <presence@MUNGEpanix.com> - 2020-07-26 04:17 +0000
          Re: Error of % + digits? Rich <rich@example.invalid> - 2020-06-30 07:59 +0000
  Re: Error of % + digits? Dieter Michel <dmichel@prosound.de> - 2020-06-22 17:19 +0200
  Re: Error of % + digits? Rich <rich@example.invalid> - 2020-06-24 20:03 +0000

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