EmiClare CPOL
A EmiClare emi window incorporating a neutral density circular polariser
for maxmium contrast enhancement and "sunlight readability".
EmiClare®CPOL windows are available in glass with VRD140 non glare or Anti-Reflective coating on the front surface or in polycarbonate with hard coated surfaces and a non-glare front surface.
General
Circular polarisers are well established as the most efficient form of contrast enhancement available. Their use in emi windows has been largely restricted to designs using a conductive coating as the shielding element which results in a significant compromise in shielding performance. In some applications a emi metal mesh and circular polariser are used giving a light transmission of the finished window in the the order of 18-22%. Optical interference patterns can also be a problem due interaction between the mesh and circular
polariser.
Circular polarisers have a light transmission of 38-42% and when combined with a high light transmission EmiClare mesh less than 5% light transmission is lost, optical interference patterns are eliminated and high level broad band shielding is achieved.
Technical Specification
| Substrates |
Glass or Polycarbonate. |
| Surface finish |
Glass - plain.
- Anti-Reflective coating(Raverage < 0.5% )
Polycarbonate
- Clear hard coat.
- Non-glare hard coat (75 gloss @ 60') |
| Thickness |
from 2.0mm. |
| Size |
450x1250mm (maximum) |
| Mesh |
EmiClare. |
| Light transmission |
>32% (visible). |
| C.E. ratio |
40:1 |
Typical EMI shielding characteristics.
| Electric Field |
| Freq.(MHz) |
1 |
2 |
4 |
7 |
10 |
|
| Atten. (dB) |
70 |
68 |
68 |
68 |
65 |
|
| Electric Field |
| Freq.(MHz) |
20 |
50 |
100 |
200 |
500 |
1000 |
| Atten. (dB) |
50 |
63 |
70 |
68 |
62 |
55 |
| Test data to MIL-STD285, 12x12" aperture. |
Termination and Edge Form
Square and step edge forms are available with a silver busbar termination as shown below.
Edges are clean cut and ground in glass and machined in polycarbonate. The busbar covers the edge and the front or back face as required.
Step edges are machine in polycarbonate and built in during the lamination of glass windows. Conductive gaskets and environmental seals can be added.
Quality
EmiClare windows are manufactured in Optical filters' ISO9001 approved facility and inspected to the Optical Inspection Standard
OIS/3.
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