ENA/MFRSR/C1 - Sensor failure (ch500)

Channel 500 died.  There was a problem with the on-site spare sensor, and then it took a 
long time to get the bad spare back and the replacement to the site.

Do not use data

• direct_normal_narrowband_filter2
• direct_horizontal_narrowband_filter2
• direct_diffuse_ratio_filter2
• alltime_hemisp_narrowband_filter2
• diffuse_hemisp_narrowband_filter2
• hemisp_narrowband_filter2

• hemisp_narrowband_filter2_raw
• diffuse_hemisp_narrowband_filter2_raw
• diffuse_hemisp_narrowband_filter2
• alltime_hemisp_narrowband_filter2
• direct_horizontal_narrowband_filter2
• offset_filter2
• hemisp_narrowband_filter2