Calibrating Manual Lensometer Help

**bobandty** · 03-08-2007, 02:21 PM

OK I figure someone on here might be able to help me! We have a pretty old Bausch and Lomb lensometer and the mires are not centered in the reticule. In fact, they line up on the second circle. I have adapted by lining my OCs up at this spot when I check in jobs and the PDs come out fine. The manual lensometers I've worked with before had a prism device on the top of the eyepiece that allowed you to line up and center the mires. This one does not have that and I'm wondering if there is some way to recalibrate the instrument so the mires are centered? I've looked everywhere on the machine, even had a knowledgable lab person/optician look at it and neither of us can figure it out. I'm thinking maybe I have to take off the plate that screws onto the device (which covers 'the works' and the light bulb) but I don't want to start messing around in there if I don't know what I'm doing. So does anyone have any ideas? Or is it even that big of a deal since my PDs check out okay? Thanks for any help, you guys are the best!

:cheers:

**Judy Canty** · 03-08-2007, 02:25 PM

My suggestion would be to send it out to someone like Latham & Phillips to have it professionally serviced.

**Dave Nelson** · 03-08-2007, 02:50 PM

temporary quick-fix: put a 2 diopter prism in the auxillary prism holder, or whatever power you need to displace the image back on center. (or remove the one thats there now.)

**cocoisland58** · 03-08-2007, 02:55 PM

Call your local lab and ask them for the traveling calibration guys number. You won't have to send it out. Our lab tech, the old curmudgeon, used to be one of these guys. I want him to teach me but who has the time?

**obxeyeguy** · 03-08-2007, 03:57 PM

If its a B & L model 70, I have fixed that before. Been a long time but dont remember it being too hard. Take off the back cover, 3 screws , 1 on each side, 1 on the bottom back. The lens focusing mech will be right there. Should have some allen screws holding lenses , use those to re_align .

**CME4SPECS** · 03-08-2007, 04:00 PM

Is there a prism lens in there that someone forgot to take out?

**mikeh** · 03-09-2007, 09:15 PM

Take off the cover. If I remember correctly, there are Allen wrench set screws that can be tweaked one way or the other to align the mires. You may have difficulty finding the right size Allen wrench. They're pretty tiny.

**hridgeway** · 03-09-2007, 10:12 PM

Originally Posted by mikeh

Take off the cover. If I remember correctly, there are Allen wrench set screws that can be tweaked one way or the other to align the mires. You may have difficulty finding the right size Allen wrench. They're pretty tiny.

You will need an offset screw driver to losen the locking screws before adjusting the allens to center the target. If you don't losen them first you got a bigger problem than you started with.