Measuring HEV radiation?

[SharonB]

Anyone have a favorite instrument for measuring HEV transmission/absorption in spectacle lenses? Or... do you think it's necessary?

[Joe Zewe]

Anyone have a favorite instrument for measuring HEV transmission/absorption in spectacle lenses? Or... do you think it's necessary?

There is a company in the UK called Viewtech that makes a sensor that plugs into an iphone or ipad. You can get a reading that shows the % of blue light blocked for any lens. I believe it is focused on the 400nm to 450nm range. It will also test UV.

I met this company at Mido and I bought one of their sensors for our booth at Vision Expo. We ran this off an ipad and it was a great demonstration tool. Ron Wright is the person I met with from Viewtech at Mido and Vision Expo. PM me and I can provide you his contact info.

[Chris Ryser]

I own and use: The neat solution for all your reflectance and transmittance applications, provides complete reflectance and transmittance solutions in just one instrument. • 190 to 1100 nm range

• Will sample film coatings, lenses, powders, liquids, paper, sheet metal etc.

- See more at: http://www.selectscience.net/product....IoMNeq5I.dpuf

[MakeOptics]

A green led can be used as a sensor for all wavelengths less than. If an array of blue LEDs were to fire at full intensity with the green led being calibrated using an analog input of a microcontroller, the values can the be used as a baseline measure for 100% transmittance. Then you can fire off the LEDs once again this time with a lens between the blue LEDs and the green being used as a sensor and then its all simple division. Since most LEDs operate on a very thin band of the spectrum a few different common blue LEDs could be used 430, 470nm. Thes two readings could be used to extrapolate a linear function for the transmittance graph in the blue range. For better curve fitting the sensor can be a yellow LED with green and near UV LEDs being calibrated and read to better estimate the curve with on both ends of the spectrum that is of interest.

Using an arduino the whole thing would cost $20 bucks and a hand full of lines of code.