| |
|
|
| Refractive Index |
nd |
1.523 |
| Density |
d |
2.52 |
| Linear Exp. coef. |
a |
93x10-7 |
| Viscosity |
Soft.Pt |
695°C |
| |
Ann.Pt. |
540°C |
| |
Strain Pt. |
500°C |
|
| AIR TEMPERING |
Air tempering uses conventional processes for photochromic
crown glasses.
Minimum lens thickness for normal air tempered lenses is 2mm. |
|
| CHEMTEMPERING
: |
|
Recommendations :
|
|
|
Time:
|
16 hr or 2hr |
|
Temperature:
|
450°C |
| Bath : |
|
|
Potassium Nitrate:
|
99.5% |
|
Silicic Acid:
|
0.5 % |
|
| COATINGS |
| Vacuum coatings for coloring, antireflection or mirror
are possible. |
|
| VISIBLE |
|
380-780 nm |
|
| Luminous transmission factor |
18.0% |
| |
|
|
|
| ULTRA VIOLET |
| UV-B |
t(max) |
280-315 nm |
0.0% |
| |
t (avg) |
280-315 nm |
0.0% |
| Solar UV-B transmission factor |
0.0% |
| |
|
|
|
| UV-A |
tl(max) |
315-350 nm |
0.0% |
| |
t(avg) |
315-380 nm |
<0.1% |
| Solar UV-A transmission factor |
<0.1% |
| |
|
|
|
| BLUE LIGHT |
380-500 nm |
|
| Blue light transmission factor |
15.0% |
| |
|
|
|
| TRAFFIC SIGNAL RECOGNITION |
|
| |
ANSI Z80.3-1986 |
Pass |
| |
AS 1067.1-1990 |
Pass |
| |
BSI 2724-1987 |
Pass |
| |
DIN 58217-1980 |
Pass |
Caution :
Lens thicknesses greater than 3 mm transmit less than the 8% visible
transmission required for driving. |
|
