Electronic Instruments Limited Milliohmmeter Model 47.

[Zoeloe44]

Hi,
My second post to this forum.
Again I have to ask for help.
I received from an old friend engineer a Miliohmmeter "model 47" form "Electronic Instruments Limited" from Richmond, Surrey in England.
It seems in perfect condition, meter, tubes, switches and so on.
It requires a 4-wire testcable to measure very low resistances.
I have no service manual or user manual, hence I can not find out how to calibrate the unit so that the measurements I take heave some sence and I can depend on them.
Any help is very much apreciated.
Cheers,
Zoeloe

[peter_scott]

Hi Zoeloe,

Welcome to the forum. I wonder if this might help..
http://www.allaboutcircuits.com/vol_1/chpt_8/9.html

Peter

[Zoeloe44]

Hello Peter_Scott,
Thank you for your reply.
I do know how to do 4 wire measurements (haven't done it for years) but I can't tell if the reading on the meter is correct.
There is a calibration option and a adjustable pot on the back of the unit.
They interact and that make's it even more confusing.
A method to calibrate the unit so that I can take the readings for beeing correct would be the max.
Thanks again; a good article btw.

Cheers,
Zoeloe

[peter_scott]

Hi Zoeloe,

I think this museum has the documentation for your meter. Perhaps they could provide a copy for a small donation.

http://www.rnmuseumradarandcommunications2006.org.uk/

Peter

[Zoeloe44]

I checked the huge number of pages but couldn't find any link to the meter in question.
Even on the Web I can't find anything except my own postings.
Maybe a picture could help to refresh someone's memory.
That's for soon.
Cheers,
Zoeloe

[peter_scott]

Hi Zoeloe,

The Operating and Service Manual for your meter is specically listed as part of the museum's archive. It's not available on line. You'd need to contact them.

Peter

[Zoeloe44]

Hello Peter,
I went through the site, the museum and many other links, pages and pictures.
But I can't find the referenced model 47.
Probably I overlooked something but don't know where.
Can you point me to the precise place to look?
I also wrote a mail to the museum.
Hopefully they wil answer my mail and solve my questions about the 47.
Thanks again Peter.
Zoeloe

[peter_scott]

Hi Zoeloe,

Try scolling down through this to Electronic Instruments
http://rnmuseumradarandcommunication...IAL%20ECHO.htm

Peter

[Zoeloe44]

Thanks Peter,
I missed that one.
I gave up after searching the site. Probably I didn't look at ALL the pages.
Must be "the age".
I'll contact them again to see if it's available.

Cheers,
Marco

[Zoeloe44]

Hello Peter,
Thank you for the link to the museum.
The instruction manual and schematic has been copied and spiral bound sent to me by mail.
Very nice folks over there...

Aha; now I know a bit more.
Let's make it work again.

Thanks you all.

Cheers,
Zoeloe