DQRID : D141216.2
Start DateStart TimeEnd DateEnd Time Data Quality Metric
10/04/2013080012/02/20142028Suspect
more
Subject:
ENA/CCN/C1 - Problem with time fields
DataStreams:enaaosccn100C1.a1
Description:
During the ENA deployment the CCN instrument clock was not synched with a time server 
until 12/2/2014.  Starting at about 11/03/2013 the CCN was 60 seconds slow.  From that time 
until the time was manually corrected on 10/07/2014 at 16:00:00 the CCN time gradually got 
faster relative to the CPC until it was approximately 10 minutes fast. On 12/2/2014 at 
20:28:30 the CCN was configured to automatically correct its time from the Unit 1 CPU.  
Since that time the CCN has been within 2 seconds of the time server except at startup.  
More recently the setting was changed to keep the CCN within about .6 sec.  Generally the 
time is being corrected by time client about once every 3 days.  

There have been 2 startups since the time synching was configured.  At these times the 
time was off by more, but was immediately corrected.  On 12/30/2014 at 19:28:01 the time was 
fast 66.235 sec. at startup.  On 01/16/2015 the time was fast 38.512 sec. at startup.

The  Document  shows the times of the peaks used to approximate the 
error in the time. The time was checked about once a week and its assumed that the time 
drifted gradually between the times in the file.
Suggestions: 
Average data for longer periods.

Compare peaks with other instruments to 
calculate
 how far off the time was.

Filter the CCN Data by the Current SS=1 to make it easier 
to see patterns in the CCN data. This helps because the CCN scans and there are steps 
when the Current SS changes. Only plotting the concentration when Current SS=1 leaves gaps, but all the plotted points start from the same level.
Measurements:enaaosccn100C1.a1:
  • time_offset
  • lon
  • CCN_first_stage_monitor_voltage
  • CCN_Q_sheath
  • base_time
  • CCN_temperature_std
  • CCN_proportional_valve_voltage
  • CCN_ss_set
  • N_CCN_bin_number
  • CCN_temperature_gradient
  • N_CCN
  • CCN_T_inlet
  • CCN_t_read_TEC2
  • CCN_t_read_TEC1
  • CCN_laser_current
  • CCN_t_read_TEC3
  • CCN_P_sample
  • alt
  • CCN_Q_sample
  • time
  • CCN_T_OPC
  • CCN_T_sample
  • lat
  • CCN_T_nafion
  • N_CCN_dN
  • CCN_temp_unstable_flag
  • CCN_super_saturation_calculated
more

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