Light meter solar cell vs selenium

[DaveP]

Hello,
I was messing about on the bench and replaced a dead selenium cell in a junk meter with a solar cell from a calculator. Not accurate at all, but the thing did respond to varying light levels. Has anyone tried this? Seems like it might work with a proper solar cell and the appropriate variable resistor. Any suggestions,experiences, schematics or any info at all? Thanks!

 

[P3tr]

This might help:
http://www.xs4all.nl/~tomtiger/zenrep/meter.html

 

[DaveP]

Thanks, thats the idea I had. Ive measured several solar cells and found different voltages and I dont know what the original selenium voltage was supposed to be. Im 1 1/2 stops off now ,much better than the three stops with the first cell I tried. This is just messing about, I have good meters. The one Im experimenting with is an Argus meter that came with a C 3, smallest meter Ive ever seen and shoe mount. Would be nice to get it going though.

 

[Edward C. Zimmermann]

The problem is not the voltage but the spectral sensitivity. Modern solar cells don't match up.

And the sensitivity of film:

 

[sevo]

In their current L-398A, Sekonic replaced the selenium cell they used in its predecessors for half a century with a silicone cell, for availability reasons. They doubtlessly got it to work. But I consider it quite likely that the (required, see the above comments on silicone spectral sensitivity) filter pack will age faster than selenium cells. The latter, in the build quality and sealing used in the 398 series, often are still good after 40 years.

 

[Ron G]

I bought an selenium cell from George Milton at Quality Light Metrics at a very reasonable price.I furnished the measurements and the one he sent was very close.
I have heard that those cells can be cut to size with a jewelers saw etc.
I have never done it.It would be interesting to try after measuring the voltage with a constant light source before and after.As it turned out I used my original in my repair after all and still have the new one for future use.Ron G

 

[oftheherd]

This might help:
http://www.xs4all.nl/~tomtiger/zenrep/meter.html

That's neat! Thanks for the link.