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Oddbjorn
Tinkerer
Username: Oddbjorn
Post Number: 1
Registered: 03-2008
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, March 25, 2008 - 03:14 pm: | 
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Hi, I have got an old Ikophot CD exposure meter. It has been laying idle for many years. The needle sometimes won't move. I have to tap the meter side vise on one corner to loosen it. Then it seems to show fairly accurate values.
I would like to get some help when it comes to open it and some advise to get the thing going. Are there any chemicals, spray cans, that can be used. I don't think it has much mechanical wear.
As you can see English is not my native tongue. I'm Norwegian, but I hope someone can help anyway.
Thank you!
Oddbjorn |
M_currie
Tinkerer
Username: M_currie
Post Number: 122
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, March 31, 2008 - 09:06 am: |
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If this is a battery meter, the first thing I would do is check the battery contacts. A little corrosion can cause that problem. If it is not that, you will need to open it up (sorry, I don't know how on that particular meter) and check for corrosion or bad connections inside.
The other thing you need to do is test for a sticking or loose meter needle. Sometimes if the meter has been dropped in the past, part of the needle can bend. The needle is on a fine pivot, and on the other end is a little counterweight. The weight can have enough momentum to bend the short end of the needle when it is dropped. A loose bearing in the pivot can also cause it to bind briefly. Sometimes this can be adjusted with a little setscrew.
Most of these meters are electrically pretty simple, but age and environmental corrosion can damage connections. Ability to repair this may depend on your ability to handle and to solder very small connections. The wires that lead to the meter movement itself are very small and fine. |
Oddbjorn
Tinkerer
Username: Oddbjorn
Post Number: 2
Registered: 03-2008
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, April 03, 2008 - 09:37 am: |
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Thank you. The battery contacts seem to have some corrosion. I will try to clean them firs, with pencil eraser perhaps. I have open it. There are some shims, very small washers, on the pivot on the flap in front of the CdS cell that must be kept in position while joining the top and the bottom of the meter but it could be done. I will try to clean the locking plate of the needle with q-tip and lighter fuel first. I don't know if I have the ability to solder the printed circuit board. Even though i have made some simple printed circuit boards some years ago. I will definitely not touch the wires to the meter movement.
Oddbjorn |
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