MAG/NEPHELOMETER/M1 - Failed humidograph

On 11/29/2012 when the ship was in port, it was noticed that the dry air flow into the 
humidigraph was low, about 5 l/min rather than 20 l/min as required. The operators were 
directed to check the valve and the HEPA filter.

On 12/5/2012, the operators reported that the Petras air drier had failed totally and it 
was later determined that the air pump in the Petras air drier had failed. The humidograph 
was repaired 12/13.

Since dry air from the humidograph is used to prepare air flowing into the dry 
nephelometer, the data for this instrument is questionable or invalid during the time the 
humidograph was out of service and during the time leading up to the failure of the air drier.

Data for this period should be used with caution, if at all.

• Aerosol backwards-hemispheric light scattering coefficient, red channel, 10um(Bbs_R_Dry_10um_Neph3W_1)
• Aerosol total light scattering coefficient, Ref. Humidograph nephelometer blue
  channel, 1 um particle diameter(Bs_B_Dry_1um_Neph3W_1)
• Aerosol total light scattering coefficient, ref. humidograph nephelometer green
  channel, 1 um particle diameter(Bs_G_Dry_1um_Neph3W_1)
• Aerosol total light scattering coefficient, reference nephelometer red channel,
  1 um particle diameter(Bs_R_Dry_1um_Neph3W_1)
• Aerosol backwards-hemispheric light scattering coefficient, reference
  nephelometer red channel, 1 um particle diameter(Bbs_R_Dry_1um_Neph3W_1)
• Aerosol total light scattering coefficient, blue channel, 10 um size cut,
  reference three wavelength nephelometer(Bs_B_Dry_10um_Neph3W_1)
• Aerosol backwards-hemispheric light scattering coefficient, blue channel, 10um(Bbs_B_Dry_10um_Neph3W_1)
• Back-scattering coefficient, green wavelength, low RH, 10 um size cut(Bbs_G_Dry_10um_Neph3W_1)
• Aerosol backwards-hemispheric light scattering coefficient, blue channel, 1 um
  size cut, reference three wavelength nephelometer(Bbs_B_Dry_1um_Neph3W_1)
• Aerosol total light scattering coefficient, reference nephelometer green
  channel, 10 um particle diameter(Bs_G_Dry_10um_Neph3W_1)
• Aerosol backwards-hemispheric light scattering coefficient, green channel, 1 um
  size cut, reference three wavelength nephelometer(Bbs_G_Dry_1um_Neph3W_1)
• Aerosol total light scattering coefficient, red channel, 10 um particle size(Bs_R_Dry_10um_Neph3W_1)