Help - search air quality data
Step 1 Data category
Site averages
For all pollutants - daily, monthly and yearly site averages are based on hourly data.
Site maximums
- For PM10 - the daily site maximum is based on hourly data. The monthly and yearly site maximums are based on 24hr averages.
- For CO - the daily, monthly and yearly site maximums are based on 8hr rolling averages.
- For all other pollutants - the daily, monthly and yearly site maximums are based on hourly data
Site exceedences
- For PM10 - the daily exceedence is based on hourly data and calculated against a threshold of 50 ug/m3. However, as there is no NEPM standard for 1 hour PM10, this measure indicates the number of relatively high hourly PM10 readings obtained throughout the course of a day. The monthly and yearly exceedences are calculated against the NEPM health standard of 50 ug/m3 using 24 hour averaged data.
- For CO - exceedences are calculated against the NEPM health standard of 9.0 ppm for an 8hr rolling average.
- For all other pollutants - exceedences are calculated against relevant NEPM health standards based on hourly data.
More information on NEPM standards.
Step 2 Data display & pollutants
In Step 2, the data can be output either as
- html table
- graph
- comma-separated file in csv format for import into spreadsheet applications.
If 'Display data as graph' is selected, a graph will be presented on a new page, as shown in the image below.
NOTE
If you need to return to the search form to select new pollutants or new sites, then the back button in your browser menu bar needs to be pressed twice in rapid succession.
If you need to return to the search form to select new pollutants or new sites, then the back button in your browser menu bar needs to be pressed twice in rapid succession.
Graph data display
The date range shown on the graph can be expanded or contracted using the series of icons displayed in the bar above the graph as indicated below.
Date selector - use this to select absolute dates required to be displayed and press the Refresh icon. The data will be displayed with the updated date range.
Contraction - the date range can be contracted by the number of days, weeks, months or years selected with the list boxes.- Expansion - the date range can be expanded by the number of days, weeks, months or years selected with the list boxes.
- Mouse selection - on the graph, the date range can be changed by using the mouse to paint the area to be displayed
- Zoom facility - date range can be changed by increasing/decreasing the size of the grey box. This selector can be dragged to a new position or the black bars can be dragged to the range required. Double clicking in the grey area of this box will display the graph with the new date range.
- Save file - the graph may be saved as an html, pdf or image file by pressing the Load button. The format can be selected using the list box.
Page last updated: 05 June 2008