After digging around I found that Osram seems to filter some UV on purpose. I plan to do a comparison between the Beckman and Osram lamps. The noise I see is in the range handled by the halogen bulb.
Link to Osram site, with filter infor shown below:
http://www.osram.ec/osram_ec/Servicios_y_herramientas/Training_%26_Knowledge/FAQ/Environment/index.html#answ21
UV filter technology
Question
Why does OSRAM use UV filter technology in halogen lamps to protect the environment and our health?
Answer
In addition to light, halogen lamps emit ultraviolet radiation (rays). Quartz glass used for conventional lamps allows these UV rays to freely pass through the bulb. In order to prevent this, OSRAM is the first lamp manufacturer to use UV filter technology for its entire range of halogen lamps. OSRAM halogen lamps are made of quartz glass that is doped, meaning that it has been enriched with substances that absorb UV rays. This significantly reduces the amount of unwanted UV rays in the light.
OSRAM UV filter technology is highly effective in preventing UV-B and UV-C rays from penetrating the glass. These high-energy rays can cause sunburn and conjunctivitis. Only half of the low-energy UV-A rays go through the glass. Another advantage of doped glass is that it reduces fading effects on textiles due to UV rays.