Exploring the symbols on a analog multimeter QUIZ

[Kiriakos-GR]

On the bellow picture there are seven symbols.

From left to right:
1 = warning  ( High voltage ? )
2 =  unknown ( Help !! )
3 = AC/DC  ( I know that ) LOL
4 =  1.5 Ohm ( of what ? about what ?)
5 =  accuracy less or equal of 1.5% 
6 =  meter orientation horizontal
7 =  tested to 3.000V  ( ?)

Confirm my findings and add the unknown. 
Plus you can add more symbols ( picture 800x800) from your analog one,
and help this topic to become a small library of symbols found on analogue multimeters.
Or you can add your own unknown symbols,  and hope for the best as I do. LOL

[vk6zgo]

I think #2 is to indicate the meter is diode protected,so that the worst case overload across the meter coil is the diode forward drop of approx 0.6 volts.
 VK6ZGO

[ipman]

If my memory serves well, the second symbol means that the meter can measure both ways. Something like digital DMM's: you can put probes not paying attention to polarity.

[lebeno]

Something much simpler, 30V panel meter from Kyoritsu.

[Kiriakos-GR]

I think #2 is to indicate the meter is diode protected
 VK6ZGO

Yes this meter it is diode protected. 

And so the turn over U it describes that on it there is a magnetic controlled circuit = needle PLUS protected with diode,
against reversed polarity.

Additionally the turned over T translates as: Only for vertical placement, and all the panel meters have it.
Like the Kyoritsu above.

[zaoka]

Is it really under 1.5% accuracy?

I remember having MetraMax 7 by Gossen Metrawatt it was +- 15%..

[Kiriakos-GR]

It is :
Ohms range  +/_  0.7%
DC range +/_ 1.5%
AC range +/_ 2.5%
40Hz - 500Hz

For square wave measurement you add 11% at the reading.
For triangle waves you have to extract 4% .

This is why I love it.. high tech analog.  ;-)

[qno]

The meter is an moving coil meter so it is only able to show DC currents not AC.
With moving coil meters the current in the coil is the source of the EMF to move the needle.

I think the second symbol means that the AC measurement is done by diode rectification.
So the needle indicates the Average value of the AC current. Not the effective value.
The scale however is calibrated in the effective value for sinusoidal waves.
If the current is not a sinus you have correct the measured value with a correction factor.
If you do not now the waveform of the input voltage the meter is useless. As for all non True RMS meters.

If it only has diodes for rectification the lowest AC voltage scale usually is 10V with a non linear scale and no AC current range.



I think symbol 3 and 4 belong together indicating the accuracy of 1.5% for AC and DC.
Symbol 5 and 6 indicate an accuracy of <1.5% for the ohms range.

Having this kind of precision the meter scale should have a mirror to prevent the Parallax effect.

Symbol 7 is to indicate the position the meter is calibrated in. In this case horizontal.

Symbol 8 is the test voltage for the user. This means that a test voltage is put on one of the inputs and the ground is swiped all over the instrument. The current to ground should not exceed a safe level. This meter is tested for 3 kV.

[Bored@Work]

Symbol 1 means "read the manual".

[Kiriakos-GR]

If you do not know the waveform of the input voltage the meter is useless. As for all non True RMS meters.

True, and I have not see even at 2011 one digital DMM to report what waveform type was measuring.
By this note in mind, I can no blame any multimeter as useless yet.

Regards.

[Neganur]

German DIN explanations:

1: Achtung, Gebrauchsanleitung beachten.
2: Drehspulmeßwerk mit Dauermagnet, mit Gleichrichter
3: Gleich- und Wechselstrom
4: Klassenzeichen für Anzeigefehler, bezogen auf den Meßbereich-Endwert
5: ? not sure if this is part of DIN43802 or something Metrawatt use. Guess: ohmmeter scale accuracy
6: Klassenzeichen für Anzeigefehler, bezogen auf Skalenlänge bzw. Schreibbreite
7: Waagerechte Nennlage (Gebrauchslage)
8: Prüfspannung 3 kV

translated into English:

1: Read the manual
2: Rectified moving coil meter, permanent magnet
3: AC and DC
4: Accuracy class 1,5 * meaning +/- 1,5 % of the maximum scale value (for example 75 mV range -> +/- 1,125 mV)
5: No idea, I don't recognise this as a DIN sign for analog meters. Ohmmeter scale accuracy ?
6: Accuracy class 1,5 * meaning +/- 1,5 % of the scale length (for example 70 mm scale length -> +/- 1,05 mm) most likely for the non-linear Ohm scale
7: Horizontal working position
8: Testing voltage, 3 kV for 1 minute

* There are certain exceptions in DIN 43780 and DIN 43802 which allow additional -1 % error in the 3 V~ range for 0...1,5 V~
* Does the resistance scale arc line eventually vary in thickness? The photo you attached cuts the first third of the scale. If it indeed is a little wider/thicker it means there's an error of +/- 10% of the measured value for this part of the scale.

[Kiriakos-GR]

Ok lets go full screen. 

And bellow partially translated the manual.

[EEVblog]

Is it really under 1.5% accuracy?

A good analog meter could hit around that figure IIRC.

Dave.

[Neganur]

Excellent picture, what a beautiful meter.

Ohms range  +/_  0.7%

The manual mentions this as the temperature coefficient per 10 Kelvin, not the ohms range tolerance. I believe the tolerances for resistance measurements is +/- 1,5 % of the scale length, which is 77 mm.
Nice to see the manual including a list of burden voltages. Do you need help translating the manual ?

Oh, regarding the accuracy of analog measuring elements, class 1,5 is pretty standard.
They are divided into two categories
-Betriesmessgeräte (field instruments): class 1 - 1,5 - 2,5 - 5 and
-Feinmessgeräte (precision instruments): class 0,1 - 0,2 - 0,5

This classifies the intrinsic error (German: "Grundfehler/Eigenabweichung") of the meter itself.

[Kiriakos-GR]

Thanks to another German manufacturer of industrial panel meters ( REDUR panel meters) ,
I found the chart below.
An almost detailed explanation about many aspects of the analog German made meters.
I love this document, its another little treasure for any one who cares to find the all truth about this subject.     

[Neganur]

I'll translate the text later, thought you might find this useful anyway. It's in German.

[firewalker]

From a book of mine (Greek).

[Kiriakos-GR]

Great info from international sources !!   

What looks interesting are the star marking = tested up to specific voltage.
The star with out anything in it, translates in to a minimum of 500V.

(People please keep the file size in to a minimum of 400k max)   

[Kiriakos-GR]

I'll translate the text later, thought you might find this useful anyway. It's in German.

I did try to learn the German language, as second foreign language in my youth.
But six months later we lost the teacher. 

The number of the students got small , and the public school terminated the program for additional foreign languages,
after the end of the standard teaching hours.

I could use some help about translating more parts of the MA4S manual , but I need some one with patience,
there is several pages in it.
The PDF that I made , has the most important basic pages.