FHWA and EPA National Near-Road Study - Detroit

17 Appendix - Data Checks

Level 1

Check to see if all variables are listed in each file. Continuous data has all variables for all stations even if station does not have that specific instrument installed.
Sound data, traffic, spans, zeros, integrated (PM_2.5, 1,3-butadiene, benzene, acrolein, formaldehyde, acetaldehyde) data are either recorded in separate files or recorded and stored in separate files.

Measurements		10 Meter Roadside	100 Meter Downwind	300 Meter Downwind	100 Meter Upwind
Continuous Analyzer Data -- Data stored by Station ID - 4 separate files.
	Continuous gas monitoring (CO, NO_x)	X	X	X	X
	Continuous black carbon monitoring (Aethalometer)	X	X	X	X
	Continuous fine particle (TEOM)	X	X	X	X
	Wind speed/wind direction	X	X	X	X
	Meteorological monitoring (temp, RH, etc.)		X
Integrated -- VOC data stored as separate file, PM_2.5data stored as separate file.
	TO-11A Cartridge sampling	X	X	X	X
	TO-15 Canister sampling	X	X	X	X
	Integrated PM_2.5 (FRM)	X	X	X	X
Other Continuous - Stored as separate files by pollutant or type (sound, video, etc.)
Video Camera		X			X
Traffic Data - Stored as a separate file

Level 2 Check

Check to see if zero volt reference channel (0_Vref) is equal to zero and five volt reference channel (Vref) = 5.03. Five volt reference channel value is shelter specific. (All other records should be labeled as invalid.)
Check to see if continuous data are being recorded every five minutes.
Check to see if continuous GC data are being recorded every 30 minutes
Check between continuous analyzer data files to determine if time sync is correct. For example, data points are being recorded every 5 minutes. The time stamp for each file should be…. 00:05, 00:10, 00:15….23:55.
Check to see if traffic data contains both north bound and sound bound data.
Check to see if traffic data is being reported every 15 minutes (approx.).

Level 3 Check

Perform summary statistics and inspect for variability issues
Check traffic data to determine if sum of traffic volume by length bins is approximately equal to total volume count.
Check Outliers: Values that are 3 standard deviations from the mean
LowHigh: Check the lowest 5 values and the highest 5 values for all parameters.
Jumps: Checks to see if data quickly rises and then drops. There are macro variables that control the sensitivity (need to discuss sensitivity of the macro variables).