Speed cameras front of camera van
Discussion
Highly unlikely.
"Laser speedmeters must not be used through glass or plastic screens to avoid diffraction
or scattering of the laser beam. While vehicle screens pass light with minimum diffraction,
elements within vehicle screens, as well as their cleanliness, makes the path of laser light less
predictable so it is discouraged in law enforcement devices. They can be used from within
vehicles through an open aperture, such as a window.
Take care that lenses are not damaged or dirty by not placing the instrument in a position
where this can occur. Make a visual inspection of the equipment for damage before use."
http://library.college.police.uk/docs/appref/NPCC-...
These are only guidelines though and not law so technically from a legal point of view, they could operate through glass.
"Laser speedmeters must not be used through glass or plastic screens to avoid diffraction
or scattering of the laser beam. While vehicle screens pass light with minimum diffraction,
elements within vehicle screens, as well as their cleanliness, makes the path of laser light less
predictable so it is discouraged in law enforcement devices. They can be used from within
vehicles through an open aperture, such as a window.
Take care that lenses are not damaged or dirty by not placing the instrument in a position
where this can occur. Make a visual inspection of the equipment for damage before use."
http://library.college.police.uk/docs/appref/NPCC-...
These are only guidelines though and not law so technically from a legal point of view, they could operate through glass.
The Approval has nothing to do with restricting the use through glass, there are no such restrictions in the Approval.
Use through glass is not encouraged and the guidance referred to above says that. Good advice.
Whether the laser can be relied upon in a measurement will depend entirely on the circumstances. As the laser uses glass lenses, some use plastic, use through glass is of course possible. If your car is in a crowded scene then the viability of the aiming is reduced when used through glass windscreens. The windscreen is not likely to alter the aiming but there is a possibility it might so the recommendation is to eliminate the chance by not using it through a screen.
If you are the only car in view and the laser makes a speed measurement then the use through a windscreen is completely irellevant and there is no chance the speed reading is in error.
When you think about it, if the screen was going to be distorting the laser aim then how would you see to drive?
Use through glass is not encouraged and the guidance referred to above says that. Good advice.
Whether the laser can be relied upon in a measurement will depend entirely on the circumstances. As the laser uses glass lenses, some use plastic, use through glass is of course possible. If your car is in a crowded scene then the viability of the aiming is reduced when used through glass windscreens. The windscreen is not likely to alter the aiming but there is a possibility it might so the recommendation is to eliminate the chance by not using it through a screen.
If you are the only car in view and the laser makes a speed measurement then the use through a windscreen is completely irellevant and there is no chance the speed reading is in error.
When you think about it, if the screen was going to be distorting the laser aim then how would you see to drive?
What they say and what they do are entirely different things, they want us to think that scamera vans can get you from all angles, they work in all weather conditions, they get you at night, etc etc etc.
In truth you only see them on nice dry/sunny days during rush hour to maximise profits.
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