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Clarity User Guide, March 1, 2011 - Rev. 1.06
Page 33
On the Calibration screen under Step 4 (See Fig. 4.1), there are six parameters that describe
the lens that will be analyzed:
1. Diameter
2. Index of Refraction
3. Power
4. Front Curve
5. Back Curve
6. Center Thickness
These parameters are for both the plus and the minus lenses.
NOTE
If these lenses are misplaced or compromised in any way, please call the factory and
order a new calibration lens. Once the new lens arrives, check these parameters and
make any necessary changes.
To perform this calibration, select the Calibrate button. You will be prompted to remove the
lens. Make sure there is no lens in the chamber and select OK. After 25 seconds, you will be
prompted to insert the calibration lens. Put the -6.00 lens in the chamber and select OK. The
Clarity will analyze the lens and will instruct you to place the +6.00 lens in the chamber.
Select OK.
After both lenses are analyzed, the plus and minus slope adjustments will be displayed. Select
YES to accept these changes. The calibration wizard will appear telling you that the power
calibration is complete. Select OK. To exit back to the Job screen, select OK at the bottom
of the screen and then on the next screen select Next.
NOTE
On this screen, there is also a Power Offset box. This can be used if you see a consistent
power error. For example, powers are showing 0.25 weak across the board. Enter a
+.25 and all analyzed powers will have 0.25 added to the final reading. This functions
like the manual eyepiece adjustment for power on a conventional lensometer.
This screen includes two parameters labeled Minus Prism Bias and Plus Prism Bias.
They are constants and should not be changed unless directed by the factory.
To verify power calibration, there is an internal job (Job Number 999999999) which will
allow you to use the two calibration lenses (+6 and -6). From the main Job screen enter the
Job Number 999999999 and follow the directions. Each lens will show the measured power
in the upper right hand corner of the screen. If they are within acceptable limits, you can
move on. If they are out of tolerance, recalibrate.