Seek and measure lens cener thickness only an exact point you 


Lens Center Thickness Gauge

  CTgauge S   /   CTgauge R

Now fast and  non-contact lens center thickness measurement is available along with H(Sagmeasurement.  Also  go no-go decision function and measurement certificate output are included.

Feature ②

  To improve accuracy of the center thickness measurement 



This machine measures displacement in the vertical direction. The machine is a kind of end measuring machine. In order to calibrate the machine, gage blocks are required to calibrate vertical displacement. It is also critical to measure the displacement precisely along the axis of the lens. Specific procedure of the calibration is explained below.  


Feature ②-1 Calibration


Calibration procedure

【  Comparison to gage blocks  】

The Z-axis encoder must be precisely calibrated using the number of gage blocks. As measurement of the lens thickness is made by reflection of light, the measurement does not depend on the refractive index of the lens material.                                            




【  Placement of gage blocks on the stage 】


The gage blocks must be placed in the same configuration for every calibration. For this purpose, permanent magnets are installed in the jigs. 

Feature ②-2 Tilt adjustment device and 3-D Map


 Means to prevent measurement along the inclined axis  



【  Tilt adjustment device  】


Adjustment of the right angle between the displacement sensor and the specimen can be made using the optical flat. Tilt adjustment device that does not easily shift is used.      





The specimen holder stage is placed at a right angle to the displacement sensor. In order to establish the right angle, measurement is made using the optical flat to indicate the direction the stage is tilted using the 3-D map.  Then adjustment of the tilt angle can be made. 




  【  Horizontality check of the stage by the 3-D map  】


Tilt adjustment of the stage is required to avoid the incidence of measuring light to the specimen not at a right angle. This machine has the capability to provide a 3-D map view of the measured surface. This feature allows easy identification of the direction the stage is tilted.