Essilor Instruments ALM 500, Руководство пользователя, Страница: 34 / 46

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7.3 7.3 7.3 7.3 Marking of Prism Lens Marking of Prism Lens Marking of Prism Lens Marking of Prism Lens
In case that prescription is expressed in X-Y
(1) Select “X-Y” from “Prism” on the “Setup” screen.
(2) Move the lens so that the prism values
displayed on the screen match with the ones on
the prescription.
The meanings of the prism values displayed are as shown below.
Px I Base In (base inward)
Px O Base Out (base outward)
Py U Base Up (base upward)
Py D Base Down (base downward)
In case that prescription is expressed in P-B
(1) Select “P-B” from “Prism” on the “Setup” screen.
(2) Move the lens so that the prism values
displayed on the screen match with the ones
in the prescription.
P: Prism value
B: Base direction
In case that prescription is expressed in mm
(1) Set “Prism (mm)” as “On” on the “Setup” screen.
(2) Move the lens so that the prism values
displayed on the screen match with the ones in
the prescription.
The arrows ( ) indicate the direction of
the measuring position on the lens from its
optical center.
Measuring
point
Optical
center