GRW/AOS/M1 - CCN Detector misalignment

The CCN signal was unusually low about 100 particles/cc. The %SS growth curves were 
asymmetrical. Upon consultation with the manufacturer, DMT, it was predicted that the OPC 
detector was clogged or misaligned. I had the tech, Carlos, remove the detector and ship it 
back to Boulder. The detector was cleaned. An o-ring for a lens wasn't properly seated. The 
OPC was sent back to GRW and installed. Data looks normal after the reinstallation on 
July 13th.

• AOS number concentration of CCN(N_CCN)
• AOS CCN number concentration by bin(N_CCN_dN)
• AOS bin number of lowest channel of OPC include in summation of N_CCN(N_CCN_bin_number)

GRW/AOS/M1 - CCN signal decline

There was a slow decline in the CCN signal from January to June of 2010 at GRW. The reason 
for this decline is unknown as all the instrument operating parameters appear normal. 
The decline was likely from a change in the CCN column thermal properties or a clogging of 
the detector inlet.

• CCN_laser_current
• CCN_dT_TEC3_TEC1_StdDev
• CCN_P_sample
• CCN_temp_unstable_flag
• CCN_ss_set
• Size of upper limit of each CCN bin(CCN_UpperSizeLimit)
• CCN_Q_sample
• CCN_T_TEC2
• CCN_T_TEC1
• CCN_T_nafion
• CCN_Temperature_Gradient
• CCN_FirstStageMonitorVoltage
• CCN_T_TEC3
• CCN_T_OPC
• CCN_ss_calc
• CCN_T_sample
• CCN_Q_sheath
• AOS number concentration of CCN(N_CCN)
• CCN_T_inlet
• AOS CCN number concentration by bin(N_CCN_dN)
• CCN_ProportionalValveVoltage
• AOS bin number of lowest channel of OPC include in summation of N_CCN(N_CCN_bin_number)