Gossen luna pro battery replacement??

[popscan]

I have acquired 3 Gossen Luna Pro cds exposure meters. Two of the meters have use Mallory PX 635 or PX 13
batteries in it. Those batteries are 1.5 volt alkaline The other gossen says to use two 1.35 volt mercury cells which are no longer manufactured. I already know the alkaline cells can give erroneous readings in a long run as the power curve is not desirable. WHAT BATTERIES AND OR ADAPTERS SHOULD ALLOW ME TO USE ALL THREE METERS WITHOUT INTERNAL MODIFICATIONS ??

[blueribbontea]

I have acquired 3 Gossen Luna Pro cds exposure meters. Two of the meters have use Mallory PX 635 or PX 13
batteries in it. Those batteries are 1.5 volt alkaline The other gossen says to use two 1.35 volt mercury cells which are no longer manufactured. I already know the alkaline cells can give erroneous readings in a long run as the power curve is not desirable. WHAT BATTERIES AND OR ADAPTERS SHOULD ALLOW ME TO USE ALL THREE METERS WITHOUT INTERNAL MODIFICATIONS ??

http://rick_oleson.tripod.com/index-111.html
Take a look at this easy solution. I did it for my Minolta SRT cameras and it is a cheap and easy fix.

[Jerry Bodine]

When I recently sent my Lunasix to Quality Light Metric in Hollywood for calibration, I asked (George Milton) about the batteries. He said two 1.5v PX625A are adequate and it's not necessary to use the Gossen Adapter to reduce the voltage. He calibrated the meter with those batteries and I've had no issues.

[popscan]

http://rick_oleson.tripod.com/index-111.html
Take a look at this easy solution. I did it for my Minolta SRT cameras and it is a cheap and easy fix.

I just popped in two inexpensive #675 1.4 volt batteries in each of the three exposure meters and everything worked like new!!!!!!!!!! I thank you very much for your prompt reply as I was ready to give up. The battery check needle even swung to the proper mark showing the voltage was where it was supposed to be.

A million thanks.

[Michael E]

Zinc/Air cells don't last long, once they are activated. Mercury cells lasted for years in most cameras or light meters, Z/A cells dry up quickly.

[Tobias Key]

I bought the Gossen adaptor. I can't see the point of fudging something as fundamental as accurate exposure readings.

[Dan Fromm]

Well, if George says his fix works I believe him. However, my Luna Pro (= Lunasix 3) has never been to Quality Light Metric so it has the Gossen adapter with a pair of SR-44s. It agrees with my Master V, which has been to QLM, and with my L-328.

[Kevin Crisp]

I also had QLM calibrate my Luna Pro for 1.5 volt batteries. It works just fine.

[HMG]

A #9 o-ring also works. And is much more professional. :) That's what I use in OM1 and SRT101

I'm curious though how well the z/a batteries, which require air to activate, will work when stacked (and the holes of one are blocked by the other). Or is it that once activated they stay activated.

[Dan Fromm]

I've tried them, once activated they stay activated. If you try them, don't panic if a battery check done as soon as the tabs have been removed and the cells put in the camera or meter says they're no good. They take a while to come to full voltage. Don't ask how I learned that.

[MartinP]

I have been using the Gossen adapter, with the appropriate silver cells, for years. Cheap and simple and guaranteed. Last time, the meter came back from calibration at Gossen with a certificate showing no variation greater than 1/8 stop anywhere in both ranges, which is better than I will ever need, so I think the official adapter works. Unfortunately, Gossen have since stopped servicing the Luna Pro 3, but never mind - calibration is still easy to arrange, so long as nothing breaks.

[blueribbontea]

Zinc/Air cells don't last long, once they are activated. Mercury cells lasted for years in most cameras or light meters, Z/A cells dry up quickly.

Yeah; I had to replace mine after a year!