Weston Master IV Exposure meter

[Rachel]

My first proper exposure meter was a Weston Master IV. I still have it but some time ago I noticed that it wasn't working. Today I thought I'd try to see what was causing the problem so I've taken off the back plate which exposes the meter movement. Then I noticed that the needle is moving again so I think that the back plate or some part of it has been pressing on the movement preventing it's action. I also noticed that the zero adjustment on the back plate was way out of line and not engaging in the movement adjuster. So I've repositioned that and the meter seems to be working again ... except that the scale in the meter window now does not move when I open the light cell baffle. I can't quite see how that works. Can anybody help with advice on that? Thanks.

[mickeyobe]

Jul 1, 2013 8:34:14 GMT -5 Rachel said:

My first proper exposure meter was a Weston Master IV. I still have it but some time ago I noticed that it wasn't working. Today I thought I'd try to see what was causing the problem so I've taken off the back plate which exposes the meter movement. Then I noticed that the needle is moving again so I think that the back plate or some part of it has been pressing on the movement preventing it's action. I also noticed that the zero adjustment on the back plate was way out of line and not engaging in the movement adjuster. So I've repositioned that and the meter seems to be working again ... except that the scale in the meter window now does not move when I open the light cell baffle. I can't quite see how that works. Can anybody help with advice on that? Thanks.

Rachel,

Try loosening the two chrome screws on the back ever so slightly and make sure the baffle is opened all the way.

Mickey

[Rachel]

Thanks Mickey but that doesn't seem to make any difference. Hmm ... just noticed if I tilt the meter upside down the scale moves so it looks as if I've disengaged some linkage inside the meter

[Stephen]

I have not got a spare to check, and I am a bit loath to disturb my working one, but a friend has a box of bits of them, and I can look into the issue as soon as he is available. It must be the linkage at the side that is not working.
Stephen.

[lloydy]

I have a virtually mint one with a dead selenium cell, it's free except for postage.

[Rachel]

Thanks for the offer lloydy but I'll see first if I can fix mine as it does seem to be almost(!) working. Meanwhile I had a look on the web, which I should have done before, and found this site Weston Master IV Disassembly and Notes so I'll see what that says.

[lloydy]

I used those instructions to check this dead meter out in the hope it was something I could fix, but it wasn't. It's a good set of instructions.

www.jollinger.com/photo/meters/autopsy/weston4-1.html

[Rachel]

Well I obviously tackled the job from the wrong side but from the photos I can see how the scale movement works so I've managed to fix it although it was a very fiddly job to do from the back of the meter. I'm very glad to have the meter working again. Thanks to those who helped with suggestions.