ENA/UHSAS/C1 - Problem with time fields

During the ENA deployment, the UHSAS instrument clock was not synced with a time server. I 
used a comparison of the peaks in the UHSAS data and the CPC or the PSAP data to 
determine how far off the clock was.  The UHSAS was always within ~2 minutes of the other 
instruments and the CPU it was attached to.  Starting from 2/18/2014 the UHSAS was ~ 45 
seconds. slow.  It gradually got faster and around 6/2014 it was within seconds of the CPC.  It 
continued in that direction and gradually became slower than the CPC or PSAP.  On 
1/22/2015 the UHSAS was ~120 seconds slower than the PSAP.  At 16:05:00 1/22/2015 the UHSAS time 
was manually set to the Unit 2 CPU time.  This was done remotely and apparantly only to 
within about 20 seconds.  

A  Document  shows the times of the peaks used to determine the time 
difference. 

During 2015 until the Domain time II was installed on 07/25/2016 the UHSAS was synced 
manually about once a month.  Between syncs it generally drifted slow.  During the period 
until 06/24/2015 the monthly correction was less than 20 seconds.  There was a gap in the 
corrections and on 10/21/2015 it was corrected from 1 minute 22 seconds slow.  The 
corrections after that were from about 15 to 35 seconds slow.  The first time sync after Domain 
time II was installed corrected the time from 1 minute 12 seconds slow.

• scattering_voltage
• time
• Particle size distribution, limited by lower_size_limit and upper_size_limit(size_distribution)
• base_time
• sheath_flow
• MET air temperature(temperature)
• sampling_volume
• time_offset
• purge_flow
• unit_temperature
• auxiliary
• reference
• current
• sample_pressure
• upper_size_limit
• flow
• lower_size_limit
• differential_voltage
• bin_num

ENA/UHSAS/C1 - High counts on three lowest channels

High counts in the UHSAS three lowest channels. Probably a contamination (a fiber on the 
jet nozzle) inside the optical chamber. Rest of the channels should not be affected.

• Particle size distribution, limited by lower_size_limit and upper_size_limit(size_distribution)

ENA/UHSAS/C1 - spikes in lower size bins

Intermittent spikes in the lowest 3 size bins. Probably a contamination that was cleared 
when a HEPA filter was installed for zero testing. Other bins should not be affected.

• Particle size distribution, limited by lower_size_limit and upper_size_limit(size_distribution)

ENA/UHSAS/C1 - HEPA filter attached to inlet

HEPA filter was attached to the UHSAS inlet for troubleshooting the issues related to DQR 
D151228.1. No ambient measurements were made during this period.

• Particle size distribution, limited by lower_size_limit and upper_size_limit(size_distribution)

ENA/UHSAS/C1 - Noisy counts / no counts

UHSAS was showing spikes in the lowest channels. An HEPA filter was attached to the inlet 
for troubleshooting. No valid data during the period with spikes and when the filter was 
attached.

• Particle size distribution, limited by lower_size_limit and upper_size_limit(size_distribution)

ENA/UHSAS/C1 - High counts in lower bins

High counts in the 3 lowest bins/channels. Possible contamination. Other bins should not 
be affected.

• Particle size distribution, limited by lower_size_limit and upper_size_limit(size_distribution)

ENA/UHSAS/C1 - High counts in lower bins

High counts in the 4 lowest bins/channels. Possible contamination. Instrument set up to 
sample through a filter for troubleshooting. No valid data from the period.

• scattering_voltage
• Particle size distribution, limited by lower_size_limit and upper_size_limit(size_distribution)
• sheath_flow
• MET air temperature(temperature)
• sampling_volume
• purge_flow
• unit_temperature
• auxiliary
• reference
• current
• sample_pressure
• upper_size_limit
• flow
• lower_size_limit
• differential_voltage
• bin_num

ENA/UHSAS/C1 - Intermittent spikes in the lowest channels

Intermittent spikes in the 3 lowest size bins. Rest of the bins should be unaffected.

• Particle size distribution, limited by lower_size_limit and upper_size_limit(size_distribution)

ENA/UHSAS/C1 - High counts in the 3 lowest size bins

High counts in the lowest 3 size bins. The rest of the bins should be unaffected.

• Particle size distribution, limited by lower_size_limit and upper_size_limit(size_distribution)

ENA/UHSAS/C1 - High counts in the 3 lowest size bins

High counts in the 3 lowest size bins. Other size bins should not be affected.

• Particle size distribution, limited by lower_size_limit and upper_size_limit(size_distribution)

ENA/UHSAS/C1 - High counts in 3 lowest size bins

High counts in the 3 lowest size bins. Other size bins should not be affected.

• Particle size distribution, limited by lower_size_limit and upper_size_limit(size_distribution)

ENA/UHSAS/C1 - Intermittent spikes in the lower size bins

Intermittent spikes in the 3 lowest size bins. Other size bins should not be affected.

• Particle size distribution, limited by lower_size_limit and upper_size_limit(size_distribution)

ENA/UHSAS/C1 - Instrument not sampling ambient air

Instrument was periodically offline or not sampling ambient air for troubleshooting 
purposes. Data missing or no valid data.

• scattering_voltage
• Particle size distribution, limited by lower_size_limit and upper_size_limit(size_distribution)
• base_time
• sheath_flow
• MET air temperature(temperature)
• sampling_volume
• purge_flow
• unit_temperature
• auxiliary
• reference
• current
• sample_pressure
• upper_size_limit
• flow
• lower_size_limit
• differential_voltage
• bin_num

ENA/UHSAS/C1 - High counts in lower size bins

High counts in the 3 lowest size bins. Other size bins should not be affected.

• Particle size distribution, limited by lower_size_limit and upper_size_limit(size_distribution)

ENA/UHSAS/C1 - missing data

Instrument's internal hard drive was full and no new data was being saved except a few 
samples occasionally.

• scattering_voltage
• time
• Particle size distribution, limited by lower_size_limit and upper_size_limit(size_distribution)
• base_time
• sheath_flow
• MET air temperature(temperature)
• Altitude above mean sea level(alt)
• North latitude(lat)
• sampling_volume
• time_offset
• purge_flow
• unit_temperature
• auxiliary
• reference
• current
• sample_pressure
• lower_size_limit
• upper_size_limit
• flow
• differential_voltage
• East longitude(lon)
• bin_num

ENA/AOS/C1 - Instrument mentors working at the site

Instrument mentors working at the site. Sample lines and electrical connections being 
reconfigured. Instruments that had no work done on them may still be affected.

• scattering_voltage
• Particle size distribution, limited by lower_size_limit and upper_size_limit(size_distribution)
• sheath_flow
• MET air temperature(temperature)
• sampling_volume
• purge_flow
• unit_temperature
• auxiliary
• reference
• current
• sample_pressure
• upper_size_limit
• flow
• lower_size_limit
• differential_voltage
• bin_num