Mystery German component

[llama]

From German WW2 surplus:
Markings:
Piko-Block
10000cm
Bopg 500V=
1500V= 033g

It's 3cm long and about 8mm diameter.
Brown bodied cylinder with 3 stripes at one end.

One end has snapped off so difficult to make any measurements and may be well off-spec anyway.

Anyone know what it could be, please? And why the strange units-of-measurement?!?
Graham

[Cobaltblue]

Sounds like a capacitor

Several countries in Continental Europe used cm for capitance value until after the war.

There was a thread about it here

https://vintage-radio.net/forum/showthread.php?t=124200

Cheers

Mike T

[G6Tanuki]

In times past, "Centimetres" were used as a measure of capacitance in some European circles (same as "Jars" were units-of-capacitance in the UK at one time).

A thread about this here: https://www.vintage-radio.net/forum/...d.php?t=124200

So what you have is an early capacitor.

[Hartley118]

There’s real food for thought here - the fact that capacitance has the dimension of length - something to ponder if you get a quiet moment over Christmas.

1cm = 1.113 pF

Happy Christmas everybody!

Martin

[julie_m]

Capacitance only has the dimensions of "length" if you consider the dielectric constant ε to be dimensionless. Otherwise, you are multiplying dielectric constant by an area (= length squared) and dividing by a length to get a capacitance; so ε has units Farads per metre. (Though a Farad is not a fundamental unit; it's something like seconds**4 times amperes squared per metre squared per kilogram.)

Dimensional analysis chucks up some strangenesses sometimes. For instance, almost nobody refers to wavelengths as being so many "metres per cycle"; but that's what you would have to multiply by cycles per second to get metres per second!

[Wellington]

I remember covering dimensional analysis in 'A'-level physics at school. I couldn't see a point to it at the time, but on the rare occasions I have to deal with maths and equations, I often come back to it as a good way to check my work.

It's amazing to think back to all that learning, much of it now forgotten It's tempting to think that it's wasted, but I suspect it still makes its presence felt in those flickerings of doubt when you 'feel' something is wrong in something you're reading (or being told).

Happy Christmas, all!

[Lucien Nunes]

I suspect 'Bopg' should read Bspg. = Betriebsspannung = working voltage.

That took me about 15 ohm-farads to type.

[llama]

Yes, it's Bspg now I look again. Well deduced! And thanks everyone for the interest.
I also have a mica capacitor which is marked <blank> cm on one side and 10,000uuF (actually micro-micro) on the other so that looks like its age is during the changeover period from cm.
Graham