Please clarify European resistor value notation for me

[Mike Noone]

Hi - Can somebody please verify that my understanding of European
resistor value notation is correct? My understanding is that the
magnitude (K/M) replaces the period, so 1K = 1K0, 1.2K = 1K2, 15M =
15M0. Also, when there isn't a magnitude (value under 1K) then an R is
added to the end - so 500 ohms = 500R, 10 ohms = 10R.

Is this all correct?

Why are there two different notation schemes? To me the European
version seems unnecessarily complicated. I just don't see a need for
it.

-Mike

 

[Joerg]

Hi - Can somebody please verify that my understanding of European
resistor value notation is correct? My understanding is that the
magnitude (K/M) replaces the period, so 1K = 1K0, 1.2K = 1K2, 15M =
15M0. Also, when there isn't a magnitude (value under 1K) then an R is
added to the end - so 500 ohms = 500R, 10 ohms = 10R.

Is this all correct?

I have seen that used a lot by clients over there. However, there was
also an instance where a US company used 1K2 but not 500R. I believe
there is some kind of former DIN standard about it, now probably
migrated into an EN document. This also specifies symbol shapes.

Why are there two different notation schemes? To me the European
version seems unnecessarily complicated. I just don't see a need for
it.

I don't find it a problem. In the US it's more complicated. Some
companies insist that you do not write 4.7nF but use 4700pF. Others want
that noted as 0.0047uF. Yet others want .0047uF.

Now if you look at languages that's a whole other game. A choke is a
smoorspoel in NL, a Drossel in Germany and so on. Non-native speakers
get thrown an extra curve by the fact that Drossel is also a song bird
over there.

 

[HKJ]

Hi - Can somebody please verify that my understanding of European
resistor value notation is correct? My understanding is that the
magnitude (K/M) replaces the period, so 1K = 1K0, 1.2K = 1K2, 15M =
15M0. Also, when there isn't a magnitude (value under 1K) then an R is
added to the end - so 500 ohms = 500R, 10 ohms = 10R.

Is this all correct?

Yes
But your do not need to write 1K0 or 15M0, just 1K or 15M is ok.

Why are there two different notation schemes? To me the European
version seems unnecessarily complicated. I just don't see a need for
it.

Maybe the reason for this notation is because it is easy to overlook a .
on a dirty schematic drawing.

 

[Jim Thompson]

Hi - Can somebody please verify that my understanding of European
resistor value notation is correct? My understanding is that the
magnitude (K/M) replaces the period, so 1K = 1K0, 1.2K = 1K2, 15M =
15M0. Also, when there isn't a magnitude (value under 1K) then an R is
added to the end - so 500 ohms = 500R, 10 ohms = 10R.

Is this all correct?

Why are there two different notation schemes? To me the European
version seems unnecessarily complicated. I just don't see a need for
it.

-Mike

"Periods" have a way of fading away from paper drawings :-(

Apparently OrCAD Capture has added this feature.

...Jim Thompson

 

[Joerg]

"Periods" have a way of fading away from paper drawings :-(

Not so much anymore but it sure was a problem with the old plotters.
Especially when the pens had been in there a while.

Apparently OrCAD Capture has added this feature.

That's why it is important that a CAD system can be set to fixed width
font. Mine can do both. With fixed at least you can see that something
must be missing.

Just imagine a missing dot on a 2.2ohm inrush limiter and someone puts a
22ohm in there. Click - POOF.

 

[Jan Panteltje]

Hi - Can somebody please verify that my understanding of European
resistor value notation is correct? My understanding is that the
magnitude (K/M) replaces the period, so 1K = 1K0, 1.2K = 1K2, 15M =
15M0. Also, when there isn't a magnitude (value under 1K) then an R is
added to the end - so 500 ohms = 500R, 10 ohms = 10R.

Is this all correct?
Yes.

Why are there two different notation schemes? To me the European
version seems unnecessarily complicated. I just don't see a need for
it.

It is simpler in Europe.
Americans still specify small caps in uF, and then say .001 uF,
we say 1nF.

 

[terry]

Now if you look at languages that's a whole other game. A choke is a
smoorspoel in NL, a Drossel in Germany and so on. Non-native speakers
get thrown an extra curve by the fact that Drossel is also a song bird
over there.

And why, in English 'speaker'. Because it emits (audible) music and
speech.
Better it be called an elecro-audi-emitter or something?

And when it comes to it, why 'tube'. The ide of a valve
regulating/controlling the flow of something is pretty good analogy.
Some tubes are even tubular! They are globular (and more valuable as a
result) or even metal?

But it doesn't matter at all as long we all understand what we are
talking about.

Antenna/Aerial
Capacitor/Condenser
Tube/Valve
Inductor/Choke/Coil
Filtering/Smoothing
...........................................................................
and ad infinitum .................

Have fun.

 

[Jim Thompson]

Not so much anymore but it sure was a problem with the old plotters.
Especially when the pens had been in there a while.



That's why it is important that a CAD system can be set to fixed width
font. Mine can do both. With fixed at least you can see that something
must be missing.

Just imagine a missing dot on a 2.2ohm inrush limiter and someone puts a
22ohm in there. Click - POOF.

The way I work a missing dot would get caught at LVS (layout versus
schematic), the netlists wouldn't match.

...Jim Thompson

 

[Joerg]

It is simpler in Europe.
Americans still specify small caps in uF, and then say .001 uF,
we say 1nF.

That would mean it's simpler since we only have uF. Everthing is bigger
here 8-D)))

 

[John Larkin]

It is simpler in Europe.
Americans still specify small caps in uF, and then say .001 uF,
we say 1nF.

We say 1 nF, and we also say 2.7 nF, which is proper scientific
notation. 2n7 is not.

John

 

[Joerg]

The way I work a missing dot would get caught at LVS (layout versus
schematic), the netlists wouldn't match.

Well, yes, same here. But that doesn't help the poor guy who reads a
faded schematic and thinks, wow, I've got that 22ohms right here.

 

[John Larkin]

Yes
But your do not need to write 1K0 or 15M0, just 1K or 15M is ok.


Maybe the reason for this notation is because it is easy to overlook a .
on a dirty schematic drawing.

Here in the USA, we keep our schematics clean.

John

 

[Jim Thompson]

Here in the USA, we keep our schematics clean.

John

In France, reading schematics must be a real challenge, what with all
the flies ;-)

...Jim Thompson

 

[Joerg]

Here in the USA, we keep our schematics clean.

Except for the occasional coffee and beer stains.

 

[Fred Bartoli]

Jim Thompson a écrit :

"Periods" have a way of fading away from paper drawings :-(

In France we learn how to use printers.

 

[Fred Bartoli]

Mike Noone a écrit :

Hi - Can somebody please verify that my understanding of European
resistor value notation is correct? My understanding is that the
magnitude (K/M) replaces the period, so 1K = 1K0, 1.2K = 1K2, 15M =
15M0. Also, when there isn't a magnitude (value under 1K) then an R is
added to the end - so 500 ohms = 500R, 10 ohms = 10R.

Is this all correct?

Yup.

Why are there two different notation schemes? To me the European
version seems unnecessarily complicated. I just don't see a need for
it.

It's not unnecessarily complicated. It's complicated on purpose, just to
confuse all the US people and apparently does quite a good job at it.
It is a retaliatory measure against the US people that began this crazy
game with totally insane units.

 

[Joerg]

Mike Noone a écrit :


It's not unnecessarily complicated. It's complicated on purpose, just to
confuse all the US people and apparently does quite a good job at it.
It is a retaliatory measure against the US people that began this crazy
game with totally insane units.

Granted, our units may be a bit impractical because almost nothing is
decimal. However, we don't change them all the time like European often
do. Let's see, what was the unit for pressure over there again? First it
was torr, then atmospheres, then bars, now its pascals. Over here it's
been PSI since before the first tires appeared. Guess what, it's still
PSI

Kilograms, kiloponds, newtons, drives people up the wall. Here it's
pounds and that's still the same as it was when Benjamin Franklin fired
up his new wood stove. Oh, and wood is still measured in cords, just
like in his days.

 

[Barry Lennox]

Hi - Can somebody please verify that my understanding of European
resistor value notation is correct? My understanding is that the
magnitude (K/M) replaces the period, so 1K = 1K0, 1.2K = 1K2, 15M =
15M0. Also, when there isn't a magnitude (value under 1K) then an R is
added to the end - so 500 ohms = 500R, 10 ohms = 10R.

Is this all correct?

Why are there two different notation schemes? To me the European
version seems unnecessarily complicated. I just don't see a need for

Your interpretation above is correct. I'm quite comfortable using both
systems, but frankly find the Euro one easier. The R or M or whatever
is a lot more visible than a .

There's at least two schemes for everything on the planet. Even down
to fundamentals about which side of the road one drives on.

You have no doubt heard about Sweden (IIRC) changing from the left to
right sometime in the 1960's? Well the Irish tried it as well, but
could not decide which would be the best, so they had a trial, trucks
and buses on the left, cars on the right!

 

[Eeyore]

Hi - Can somebody please verify that my understanding of European
resistor value notation is correct? My understanding is that the
magnitude (K/M) replaces the period, so 1K = 1K0, 1.2K = 1K2, 15M =
15M0. Also, when there isn't a magnitude (value under 1K) then an R is
added to the end - so 500 ohms = 500R, 10 ohms = 10R.

Is this all correct?

Why are there two different notation schemes? To me the European
version seems unnecessarily complicated. I just don't see a need for
it.

The @European@ methos is actually the International method. Like gallons, feet,
inches ounces and pounds, the US way is wholly unique to the 300 million or so
who live there.

The elimination of the decimal point is to avoid its loss in photocopying or
printing btw and therefore avoididng the potential confusion between say1.5k and
15k.

R is also used for ohms so 10 ohms is 10R and 0.1 ohms is 0R1

The same method is used for caps too. E.g. 2n7 in place of the clumsy 2700pF.

Some values may be expressed in more than one way. 0.1uF may be 0u1 or 100n for
example.

Graham

 

[Eeyore]

And why, in English 'speaker'. Because it emits (audible) music and
speech.
Better it be called an elecro-audi-emitter or something?

Loudspeaker is at least the same in French and German at least. Haute-parleur
and Lautsprecher.

And when it comes to it, why 'tube'. The ide of a valve
regulating/controlling the flow of something is pretty good analogy.
Some tubes are even tubular! They are globular (and more valuable as a
result) or even metal?

In the UK it's always been a ( thermionic ) valve of course. It describes what
it does rather than it's shape.

Graham