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Glass material for IR camera

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dineshkumar@hw

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Hi,

I had an outdoor surveillance camera for monitoring my school bus. Suddenly the protective glass of it was broken. Its a 24 IR LED assembly camera which records in daytime & night (using IR) as well.

When I try to replace the glass with normal glass (available in local markets like window glass), the IR reflection problem comes.

I am not technically well known. So can you advice me on purchasing a suitable glass to replace?Also is the glass requires any anti reflection coating?

Any manufacturers link will be very useful.
 

"normal" (window) glass has perfect transmission for near IR, but a certain reflection coefficient according to it's refractive index. AR coated glass is probably required for the application.
 

"normal" (window) glass has perfect transmission for near IR, but a certain reflection coefficient according to it's refractive index.
Click to expand...

Is there any limits for the reflection coefficient and refractive index based on applications?
 

If your camera has a small profile and do not require extra mechanical protection, the plastic dome with the spherical format is somewhat standard for this application, including the IR illuminator at the same kit, and will be not that hard to find it in the specialized market. Probably this is more suitable than make adaptations from cover lens belonging from different products.
 

Window glass and acrylic glass (PMMA) have both refractice index around 1.5 and respective reflection coefficients. Without an antiflective coating, they will show similar surface reflections.
 

the plastic dome with the spherical format is somewhat standard for this application
Click to expand...


Thats right. But my mechanical assembly is in rectangular shape & the IR open is circular.
I am unable to find any plastic domes with these shapes.The domes are always spherical.

Searching for glass / dome in rectangle / circle shapes now.

Any idea on these shapes?
 

There are storebought floodlights which are triggered by animals/humans walking in front of them. They have an IR detector behind a plastic shield. You may find one which is rectangular, in the size you need.

Suddenly the protective glass of it was broken.
Click to expand...

This suggests you should mount the camera where vandals cannot get at it.
 

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