SBS/MFRSR/M1 - Channel 940 drop out

Channel 940 data dropped out.  The MFRSR head was replaced on 20110125.  The 940nm data 
did not immediately come back on-line, so likely was not a head issue.  940 did come back 
on 20110126 @ 1800 UTC.

• Narrowband Direct Horizontal Irradiance, Filter 6, cosine corrected(direct_horizontal_narrowband_filter6)
• Diffuse Narrowband Hemispheric Irradiance, Filter 6, offset corrected(diffuse_hemisp_narrowband_filter6)
• Narrowband Hemispheric Irradiance, Filter 6(hemisp_narrowband_filter6_raw)
• Offset subtracted from hemispheric and diffuse filter6 data(offset_filter6)
• Narrowband hemispheric irradiance, filter 6, nominal wavelength is 935 nm(hemisp_narrowband_filter6)
• Diffuse narrowband hemispheric irradiance, filter 6(diffuse_hemisp_narrowband_filter6_raw)
• Alltime Narrowband Hemispheric Irradiance, Filter 6(alltime_hemisp_narrowband_filter6)

• Ratio of direct_normal_narrowband_filter6 to diffuse_hemisp_narrowband_filter6(direct_diffuse_ratio_filter6)
• Narrowband Direct Horizontal Irradiance, Filter 6, cosine corrected(direct_horizontal_narrowband_filter6)
• Narrowband hemispheric irradiance, filter 6, nominal wavelength is 935 nm(hemisp_narrowband_filter6)
• Offset subtracted from hemispheric and diffuse filter6 data(offset_filter6)
• Alltime Narrowband Hemispheric Irradiance, Filter 6(alltime_hemisp_narrowband_filter6)
• Direct normal narrowband irradiance, filter 6, offset corrected(direct_normal_narrowband_filter6)
• Diffuse Narrowband Hemispheric Irradiance, Filter 6, offset corrected(diffuse_hemisp_narrowband_filter6)