If this value exceeds the annual standard, report row is red . Thus, uninterrupted monitoring produces various numbers of days, depending on the length of the ozone season. If non-zero, report row is red . If non-zero, report row is red . Particulate matter is typically measured every sixth day, which results in about 60 values per year.
Some sites take measurements every day.
Mean Weighted arithmetic mean of 24-hours values. The method of calculation compensates for scheduled sampling that did not occur. If non-zero, report row is red . If non-zero, report row is red . This level may not be exceeded in any quarter of a year.