Fresnel lenses, its easy to say, have equidistant teeth on one side of the lens

Do not wipe with any organic filtrate such as ethanol.This is a Fresnel lens, which limits the frequency of incident light to a peak of 10 filaments (the peak of human red-line irradiation).Make the moving objects entering the detected sea area can make changes on the PIR in the way of measuring changes and release infrared signals. PIR is widely used in radar.

Fresnel lens.It's easy to say that there are equidistant teeth on one side of the lens.

Capable of reaching the effect on the optical wavepass (reflectance or refractive index) of a given spectral category.Traditional optical sanding equipment of the band - pass optical filter cost noble.Fresnel lenses can greatly reduce the cost of old, a case in point being the PIR.Dedusting can be first with alcohol water or general clean water rinse.If you take one.You'll notice there's a little plastic cap on each PIR.The pyroelectric infrared signal refraction (reflection) is placed on the PIR. The outside of the cap is engraved with tooth marks. The second function is to divide the detected sea area into many bright and dark areas.

Fresnel optical lens can focus the light passing through the narrow-band interference filter on the photosensitive surface of the silicon photoelectric secondary detector.

Fresnel lens is made of plexiglass, Fresnel lens has two functions: first, focusing effect, then wipe with cotton wool, after the tooth mark.