Modles

Reractive index

Density

Lead equivalent

light transmittance

PBo%

ZF3

1.71720

4.46gm/cm

0.24mmpb/mm

>85%

61.03%

ZF7

1.0600

5.2gm/cm

0.33mmpb/mm

Less than 85%

71%

ZF6

1.75500

4.77gm/cm

0.27mmpb/mm

Less than 85%

65.06%

note

For the lead glass the most important date is the lead equivalency.