Check out my new Voltmeter :D

[Helleri]

So, I bought this off a friend a few days ago (for $30.00). And, thought I would show it off a bit. I have yet to look it up, and while it's easy enough with the wealth of information provided on and in the unit. I also thought that might be fun to let people here do if they like (You know you love it when you find the old catalog example or are the first to post up a patent image). It does work and it seems to take measures in 2 volt increments (though it is easy to read between the lines...and make bad puns).





Oh and actually... Here is a good question about it (something I don't really have a grasp on that may come in useful). What is that adjustment/correction for and how do I use it?

[rusty]

They made those for quite a while. it was also the same design used for temperature recording devices for furnaces using thermocouples, the scale in that case was marked in degrees.....Classic high precision instrument :)

The slotted correction screw is to calibrate the meter, making the meter accurate to 1/2 percent in the 1930's was a bleeding edge technology, the normal ageing and drift was probably almost 1/2% per year.

The tag in the steel frame would be replaced every time it went back to the factory for recalibration, so it is possibly older than the calibration date written on it...

The printed temperature correction is because it is a volt meter and the resistance in it is made of metal wire, and changes resistance with temperature. (Took them a while to figure out how to make resistors that didn't do that)

I will let you find the catalog 's, those were very very very expensive when new ;P

[leach]

very nice find its a keeper