Transmission Coeff of Window Glass vs Wavelength?

In summary, most ordinary window glass will not transmit UV light, making it difficult to get a tan through a window. Below 250nm, there will likely be very little transmission. However, according to transmission curves provided on http://www.sinclairmfg.com/datasheets/optical3.html, most glasses will transmit near infrared light well, so wavelengths above 1000nm should be transmitted. Above 3 or 4 microns, the transmission coefficients decrease.
  • #1
dimensionless
462
1
Does anyone know how ordinary window glass behaves at different wavelengths? It obviously passes the optical band, but does it pass ultra violet and infrared wavelengths equally well? How about wavelengths above 1000nm? Below 250nm?
 
Physics news on Phys.org
  • #2
Most glasses will transmit UV light very little. That's why you can't get a tan through a window. Below 250 nm, you'll probably see almost no transmission. From the transmission curves listed on http://www.sinclairmfg.com/datasheets/transmission.htm [Broken], it appears that the near infrared transmits reasonably well for most glasses, so 1000 nm light would probably be transmitted. Above 3 or 4 microns, it looks like the transmission coefficients drop off.

Edited by moderator, Nov. 2011 -- current working link:
http://www.sinclairmfg.com/datasheets/optical3.html
 
Last edited by a moderator:
  • #3


The transmission coefficient of window glass is dependent on the wavelength of light passing through it. Generally, ordinary window glass has a high transmission coefficient in the visible light range (400-700nm) and decreases at both shorter and longer wavelengths.

In the ultraviolet (UV) region, window glass does have some transmission, but it is significantly lower compared to the visible range. The amount of UV transmission also varies depending on the type of glass and its thickness. Window glass may block a significant portion of UVB (280-315nm) and UVC (100-280nm) wavelengths, but some UVA (315-400nm) may still pass through.

In the infrared (IR) region, window glass has a low transmission coefficient. It is more opaque to longer IR wavelengths (above 1000nm) and may block most of the heat radiation from the sun. However, it may still allow some shorter IR wavelengths (below 250nm) to pass through.

Overall, the transmission coefficient of window glass is not equal across all wavelengths. It is highest in the visible range, decreases in the UV and IR regions, and may vary depending on the type and thickness of the glass. It is important to note that while window glass may allow some UV and IR wavelengths to pass through, it may not provide complete protection from harmful UV rays or heat radiation.
 

1. What is the transmission coefficient of window glass?

The transmission coefficient of window glass refers to the percentage of light that passes through the glass. It is typically measured at a specific wavelength and is affected by factors such as the thickness and composition of the glass.

2. How does the transmission coefficient of window glass vary with wavelength?

The transmission coefficient of window glass varies with wavelength due to the different optical properties of glass at different wavelengths. Generally, window glass has a higher transmission coefficient in the visible spectrum (400-700 nm) and lower coefficients in the ultraviolet and infrared regions.

3. What is the relationship between the transmission coefficient and the color of window glass?

The color of window glass is determined by the materials used in its production, which also affects its transmission coefficient. For example, clear glass typically has a higher transmission coefficient than tinted or colored glass, as the tint or color absorbs some of the light passing through.

4. How does the thickness of window glass affect its transmission coefficient?

The thickness of window glass can also affect its transmission coefficient. As the glass gets thicker, more light is absorbed and scattered, resulting in a lower transmission coefficient. This is why double-paned windows, which have two layers of glass with a trapped layer of air in between, are more energy-efficient than single-paned windows.

5. Why is it important to consider the transmission coefficient of window glass?

The transmission coefficient of window glass is an important factor to consider in many applications. In building design, it can impact the amount of natural light that enters a space and the heat transfer through the windows. In scientific experiments, it can affect the accuracy of measurements and the performance of optical instruments. Understanding the transmission coefficient of window glass can help us make informed decisions about its use in various contexts.

Similar threads

Replies
2
Views
1K
  • Atomic and Condensed Matter
Replies
3
Views
2K
  • Biology and Medical
Replies
11
Views
3K
Replies
1
Views
1K
Replies
10
Views
2K
Replies
20
Views
4K
  • Optics
Replies
16
Views
5K
Replies
2
Views
2K
Replies
29
Views
2K
Back
Top