Title: SLC SOS T200 UOU Ground 20240701 R0 Courtesy of Dr. John Lin, University of Utah - Department of Atmospheric Sciences (John.Lin@utah.edu) Prepared by Haley Humble, December 13th, 2024 (Haley.Humble@utah.edu) Award ID(s)/Grant ID(s) The award or grant unique identifer numbers. 1.0 Data Set Description Utah Atmospheric Trace Gas & Air Quality (UATAQ) Laboratory Teledyne T200 Chemiluminescence Nitrogen Oxides Analyzer Data version 0, uploaded 20250501 Data Status: Final (publication-ready, but can still be updated later if needed) Period of Interest: 2024-07-01 to 2024-08-31 Region of Interest: Salt Lake Valley, Utah Site Configuration (including coordinates and elevation): https://github.com/uataq/data-pipeline/blob/main/config/site_config.csv Data Frequency: Every 2-3 Seconds Data source: Utah Atmospheric Trace Gas & Air Quality (UATAQ) Laboratory Web address references: https://data.eol.ucar.edu/master_lists/generated/slc-sos/ Data set restrictions (i.e., indicate if data set needs to be restricted, requires password protection, contains personal info, description of any licensing, etc.) 2.0 Instrument Description Model T200 NO/NO2/NOX Analyzer Link to Teledyne T200 Manual: https://www.teledyne-ml.com/en-us/Products_/Documents/Manuals/06858E%20-%20MANUAL%20T200.pdf Table of specifications (Table 2-1 in T200 Manual) Span Noise: < 0.5% of reading (RMS) above 50 ppb or 0.2 ppb, whichever is greater Lower Detectable Limit: 0.4 ppb Precision: 0.5% of reading above 50 ppb Sample Flow Rate: 500 cm3/min ± 10% 3.0 Data Collection and Processing CALIBRATION METHOD: During the campaign, the T200 calibration was done every 1-2 weeks during down times. Calibration standards were diluted using the Teledyne 751H Zero Air System and Dilution Calibrator T700u, using zero air, and an EPA Protocol Gas mixture with certified concentrations. A two-point calibration at 0 and 300 ppb were performed per the Teledyne T200 Manual instructions. These calibration were used to correct and identify shifts in the baseline. All maintenance done by the UATAQ Lab are maintained and stored in a GitHub repository since 2021 (see links below). DATA ORGANIZATION: REMOVED DATA: Excluded 12 hours before and after calibrations and calibration checks. The only other data removed was due to power outages > 2 hours. The warmup period of 1 hour was removed. Dates removed due to Calibrations or Calibration Checks: 6/13/24 18:55 7/10/24 19:30 7/19/24 10:00 7/24/24 10:00 7/31/24 16:45 8/08/24 17:30 8/13/24 18:00 8/19/24 17:15 8/29/24 14:15 CALIBRATION CORRECTION: Divided the calibration time periods into distinct segments and applied the following steps to each segment. The calibration checks were removed, but not segmented into new sections. Only segmented when zero and span values were reset. LOWEST 1% CALCULATION: Computed the mean of the lowest 1% of non-missing values for no2_ppb and no_ppb. ABSOLUTE VALUES APPLIED: Added the absolute values of the lowest 1% correction to 'NO2_ppb' and 'NO_ppb' for the corresponding segment(s). The corrected sum of NO2_corrected and NO_corrected values was then added together to determine the 'NOx_corrected'.This method was justified since the T200 does the same thing to measure NOx (NO + NO2 = NOx). 4.0 Data Format USOS ICARTT FILE: NO_NO2_NOX_UOU_20240701_R0.ict PI_CONTACT_INFO: 135 S 1460 E Rm 819, Salt Lake City, UT 84112; John.Lin@utah.edu PLATFORM: On top of the William Browning building LOCATION: Lat 40.763, Lon -111.848, Elevation 1,430 m, Inlet Height 31.5 m ASSOCIATED_DATA: see README_USOS_T200_UOU.txt INSTRUMENT_INFO: Teledyne Model T200 Nitrogen Oxides Analyzer DATA_INFO: Units are ppb UNCERTAINTY:T200 manual; Lower Detection Limit: < 0.4 ppb, Precision: 0.5% of reading above 50 ppb ULOD_FLAG: -7777 ULOD_VALUE: N/A LLOD_FLAG: -8888 LLOD_VALUE: N/" DM_CONTACT_INFO: Haley Humble,University of Utah, Haley.Humble@utah.edu PROJECT_INFO: https://data.eol.ucar.edu/master_lists/generated/slc-sos/ STIPULATIONS_ON_USE: N/A OTHER_COMMENTS: Futher information about the UATAQ Sites: https://github.com/uataq/data-pipeline/blob/main/config/site_config.csv ICARTT FILE VARIABLES: Time_UTC, 2024-07-01 00-00-00_seconds_since_midnight_UTC no_ppb,ppb, NO concentration prior to correction no2_ppb,ppb, NO2 concentration prior to correction nox_ppb,ppb, NOX concentration prior to correction no_corrected,ppb, NO concentration corrected no2_corrected,ppb, NO2 concentration corrected nox_corrected,ppb, NOX concentration corrected 5.0 Data Remarks Missing data periods: Dates removed due to Calibrations or Calibration Checks: 6/13/24 18:55 7/10/24 19:30 7/19/24 10:00 7/24/24 10:00 7/31/24 16:45 8/08/24 17:30 8/13/24 18:00 8/19/24 17:15 8/29/24 14:15 Software compatibility: https://data.eol.ucar.edu/master_lists/generated/slc-sos/ Futher information about the UATAQ Sites: https://github.com/uataq/data-pipeline/blob/main/config /site_config.csv 6.0 References List of publications and documents: N/A 7.0 Appendix UATAQ, T200 NOX, UOU, AQ