Weston Model 853 "DR" Disassembly & Notes

Weston Model 853 "DR" Disassembly and Notes

Weston Model 853 front Weston Model 853 back

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This is the unit before we begin. Hopefully it's what we'll get when we're done.

Mine appears to be dead. The needle bounces slightly but doesn't seem to react to light.

There's not much to this unit at all. The is no calculator dial, no pointer lock, etc. The only two things the user are both on the back cover: rotate the photocell cover, which sets the "film speed" for the meter, and there's a slot-screw head for the zero adjust (it's at 6 o'clock on the recessed film speed dial area.


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Apart in Two Easy Steps

The easiest meter I've taken yet apart. There are two screws on the rear cover. Mine were slot screws. I don't know if they were put there by someone else or if Weston only used tamper-resistants on their better meters. Either way, unscrew them. Hold the case closed tightly (there are springs inside) and shake the screws out. Set aside.

Now while you hold the case closed, turn it over so it's facing up, and then gently ease the cover up and off. The problem is this: the meter needle is sandwiched between a face plate that sits on two springs, and it's extremely easy for the meter needle to get bent when this all comes apart (guess how I know this).

On mine the glass panel was loose, so be careful that it doesn't fall and break.

The photo (right) shows the three main pieces: the front cover (upper left) and the glass sitting in it, the meter face plate (face down, upper right) and the meter assembly (bottom). A spring sits on each of the two posts here (about 11 and 1'oclock).

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Meter Test and Detail

Check to see that the meter needle action is free. On my unit it was, otherwise I would have had to try and set it back on its pivots (a horrible job).

I took a simple multimeter and set it to the lowest OHMs setting, which lets me do a continuity test. If you set your meter on OHMs and touch the two leads together, you should get a reading on your Multimeter.

If you click the picture to the right, the larger photo has two blue lines I drew on it. These point to the two test points on the light meter. There's a little visible wire on the left hand side, and there's a metal strap underneath a screw on the right hand side. If you put the positive on the left-side contact and your negative lead on the right-side contact, the Weston's needle should swing. If that works, your meter action is good.

Mine passed. So I carefully held the meter and rotated the rear cover panel so that the photocell could see the world, and I aimed a flashlight at it--the meter responded. So--it decided it's going to work afterall. My favorite kind of job.

To reassemble: I dabbed a little household white glue (Elmer's) on the inside corners to hold the meter glass in place and let it dry a little. I then gently put the meter face pan in place (you can see little holes in the bottom corners where it registers with two pins), made sure the meter needle would ride across it without rubbing, and then gently pressed the top of the case into case. Then put the two rear screws in. I closed the cover and set the zero. Done..