In AirNow-Tech, there are six automatic QC checks that are run on air quality data. The descriptions of each (excluding Buddy Sites; see below for details) can be found here.
When sites are set up, default thresholds for QC checks are implemented. These default checks vary by pollutant. To view or change the QC criteria for your sites, log in to your AirNow-Tech account and click on the Sites tab at the top of the page. This will take you to a table containing each site from your agency.
Then, click on the site that you would like to view the QC criteria. This will bring you to the Edit Sites page. Click on the View QC Criteria button.
This will expand a table of the QC criteria for each parameter for your viewing. You can toggle through parameters by clicking on the drop down arrow in the Parameter box. If you would like to make changes to the QC criteria, click "Enable Editing" at the bottom of the page.
Apply a QC Change by Hour
Once in Edit mode you can change the QC criteria hour-by-hour (Local Standard Time) by typing in new values in the table and clicking "Save QC Criteria" at the bottom of the page.
Apply a QC Change to All Hours
To apply a change to all hours, enter a value in the Set All box located below the QC criteria table, and then click the "Set All Hourly Values" button below it. Once you are satisfied, select the "Save QC Criteria" button at the bottom of the page.
Selecting Buddy Sites
In addition to the QC checks in the tables above, you can also set up buddy sites in which to compare concentrations. Buddy sites work by taking the absolute concentration difference between the test data value and the average among the buddy sites at or above which data will be flagged invalid. Buddy sites are intended for sites within close geographic location to one another. To begin setup, click on Select Buddy Sites button above the QC table.
If you have saved parameters or sites, you can select them from the drop-down menu. Alternatively, you can select the parameter and sites for the buddy check using the Parameter Selector and Site Selector tools. After selecting the parameter and sites, a filtered data set will appear in the box below. From the filtered results, select the sites you wish to use using the arrow buttons on the screen.
Select a threshold for the buddy check. The threshold is the absolute concentration difference between the test data value and the average among the buddy sites at or above which data will be flagged invalid. Finally, you can choose a minimum number of buddy sites required to have valid data for the QC test to run. Select Save Buddy Sites when you are done.