Wet Pentax Digital Spot Meter

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ic-racer

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The sensor element in your light meter is likely a photodiode. These are insanely high-impedance devices, which is fancy speak for 'super-sensitive stuff'. This means that any kind of moisture in the circuitry, even if it's relatively pure/fresh water, will wreak havoc on the accuracy and linearity of the meter.

Continue drying it; the first signs are promising.

When I read this I first saw it as "...continue crying..."
I'm not so optimistic of the outcome here.
 
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hiroh

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It seems it’s working now. It goes down to zero, but I wouldn’t rely on its accuracy yet.

Any proven way to test the spot meter? Without another meter :smile:
 
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kept checking every 5-10 minutes by inserting the battery.
Don't do that! It was explained above that short circuits kill components. Dry thoroughly, in the order of days or even weeks, depending the effectivity of your method, before trying anything.
 

MattKing

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It seems it’s working now. It goes down to zero, but I wouldn’t rely on its accuracy yet.

Any proven way to test the spot meter? Without another meter :smile:

Sunny 16 is where I would start.
 

snusmumriken

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Generally speaking, electronics like that is working at very low voltage, so water damage happens slowly. Take the batteries out. Dismantle the casing as much as you can/dare. Place it somewhere pleasantly warm but not unpleasantly hot. The dash of a car is good, an airing cupboard is also good.
Leave it for a couple of days. DO ALL THIS AS SOON AS POSSIBLE!

After that, you can make sure of the job by putting the meter (still in pieces) in a lidded container with some silica gel capsules, but only if you have reactivated the latter by heating gently, eg in a slow oven, for an hour or so.

I used to run home-made stand-alone electronic devices in the field for my job (wildlife research), so I have plenty of experience of resurrecting waterlogged units!
 

DREW WILEY

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Why do you even need a meter if you've got "sunny 16" - which is all over the map anyway. I always kept one Pentax spotmeter new and unused in storage, just as a reference standard for my other ones. Right now, I have one old meter which is consistently 1/3 stop off due to water marks on the inside of the lens from an old dunking. That's easy to compensate for. My very first Pentax meter went through so much hell in the mountains that it is now held together with electrical tape, but still reads correctly! It's in storage.

A friend of mine slipped on a rock one evening in the most remote basin in the Sierra Nevada, and dunked his really expensive Zeiss lenses for his 6X6 SLR. The water was about as pure as it gets. It took us another week to get back to the car; but I successfully desiccated those to the effect you'd never know they ever were under water.
 
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