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  2. National Ambient Air Quality Standards - Wikipedia

    en.wikipedia.org/wiki/National_Ambient_Air...

    The primary standard was set at 9 ppm averaged over an 8-hour period and 35 ppm over a 1-hour period. [10] The majority of CO emitted into the ambient air is from mobile sources. The EPA has reviewed and assessed the current scientific literature with respect to CO in 1979, 1984, 1991, and 1994. [11]

  3. Atmos clock - Wikipedia

    en.wikipedia.org/wiki/Atmos_clock

    The first clock powered by changes in atmospheric pressure and temperature was invented by Cornelis Drebbel in the early 17th century. Drebbel built as many as 18 of these, the two most notable being for King James VI & I of Britain, and Rudolf II of Bohemia. The King James clock was known as the Eltham Perpetuum, and was famous throughout Europe.

  4. Pollutant Standards Index - Wikipedia

    en.wikipedia.org/wiki/Pollutant_Standards_Index

    This 3-hour PSI is unique to Singapore and was introduced in 1997 to provide additional air quality information which would better reflect a more current air quality situation. [3] In 2016, the 3-hour PSI was phased out on the grounds that the 1-hour PM 2.5 reading was a better indicator of the current air quality.

  5. NowCast (air quality index) - Wikipedia

    en.wikipedia.org/wiki/NowCast_(air_quality_index)

    PM 2.5 AQI of US monitors, calculated utilizing NowCast, courtesy US EPA PM2.5 AQI map, calculated utilizing NowCast, courtesy US EPA. The PM (particulate matter) NowCast is a weighted average of hourly air monitoring data used by the United States Environmental Protection Agency (USEPA) for real-time reporting of the Air Quality Index (AQI) for PM (PM 10 - particles less than 10 micrometers ...

  6. Air quality index - Wikipedia

    en.wikipedia.org/wiki/Air_quality_index

    An individual score (Individual Air Quality Index, IAQI) is calculated using breakpoint concentrations below, and using same piecewise linear function to calculate intermediate values as the US AQI scale. and The final AQI value can be calculated either per hour or per 24 hours and is the max of these six scores.

  7. Air quality guideline - Wikipedia

    en.wikipedia.org/wiki/Air_quality_guideline

    For ozone (O 3), the guidelines suggest values no higher than 100 μg/m 3 for an 8-hour mean and 60 μg/m 3 peak season mean. [2] For nitrogen dioxide (NO 2), the guidelines set 10 μg/m 3 for the annual mean or 25 μg/m 3 for a 24-hours mean. [2] For sulfur dioxide (SO 2), the guidelines stipulate concentrations not exceeding 40 μg/m 3 24 ...

  8. Time from NPL (MSF) - Wikipedia

    en.wikipedia.org/wiki/Time_from_NPL_(MSF)

    The Time from NPL is a radio signal broadcast from the Anthorn Radio Station near Anthorn, Cumbria, which serves as the United Kingdom's national time reference. [1] The time signal is derived from three atomic clocks installed at the transmitter site, and is based on time standards maintained by the UK's National Physical Laboratory (NPL) in Teddington. [2]

  9. Effects of time zones on North American broadcasting

    en.wikipedia.org/wiki/Effects_of_time_zones_on...

    The most common set of programming chosen by Central Time Zone stations aligned with the Big Three television networks (ABC, CBS and NBC) is to air a local newscast at 5:00 p.m., national news at 5:30 p.m., another local newscast at 6:00 p.m. and syndicated programming at 6:30 p.m., though some Fox stations that maintain a newscast schedule ...