lensmeters

[Kevin Howtopat]

I use a Marco lensmeter and was wondering if anybody knows a trick to clean out what I assume are dust particles inside the lens housing? They are extremely visible when the power wheel is turned to -.75

[chip anderson]

You tried an air compressor with a blower nozzle? If you can git in dar you might try a fine paint brush.
Then if all else fails there is taking it apart.

Chip

[Chris Ryser]

If the dust can not be removed from the outside surfaces the the ooptical system must be opened. If you are not used to do such jobs, better give it to an optical instrument repair specialist.

[pegasus]

If the dust can not be removed from the outside surfaces the the ooptical system must be opened. If you are not used to do such jobs, better give it to an optical instrument repair specialist.

I agree with Chris. I have a Topcon lensometer that had some visible dust like yours. I did disassemble it very far and used some canned air to try and get the dust/dirt out. The dirt is deeper in than I care to dig into it. I am just living with the problem as the instrument does not get a lot of use.
Joe

[Barry Santini]

By racking the eyepiece focus through its travel, you can determine if the dust is on an eyepiece surface, and even which one. If it comes and goes with power wheel position or rotates with the acis wherl then it resides on the rear end.

[Howard Gorin]

Does the dust revolve with the target?*If it does then the dust is on the target. *The fix is simple. *Remove the three screws that hold the cover on. *One screw is under the power wheel. *It is not tight anyway, leave it alone. Remove the cover. *Wipe off the target. *Do not worry about the back of the target, *removing it will**cause trouble. *leave it alone. *Clean the eye piece out side surface. *Put the cover back on and replace the screws.
Problem solved!
Taking anything else apart will cause more trouble then it is worth

[sharpstick777]

Welcome to Optiboard Howard, great advice!

Does the dust revolve with the target?*If it does then the dust is on the target. *The fix is simple. *Remove the three screws that hold the cover on. *One screw is under the power wheel. *It is not tight anyway, leave it alone. Remove the cover. *Wipe off the target. *Do not worry about the back of the target, *removing it will**cause trouble. *leave it alone. *Clean the eye piece out side surface. *Put the cover back on and replace the screws.
Problem solved!
Taking anything else apart will cause more trouble then it is worth