The 100 meter sprint time drag adjustment calculator is a vast improvement over previous calculators which have previously ignored the effects of temperature, humidity, and barometric pressure. These three values serve to "fine tune" the physical altitude of the venue, introducing a new variable called density altitude. A temperature difference of 20 Celsius at a particular venue can change the air density by almost the same amount as a 600 meter gain in altitude! Humidity variations and varying barometer can have an additional impact.
Although density altitude is usually used to calibrate readings with respect to the "Standard Atmosphere" (Sea level, 101.3 kPa, 15 Celsius, 0% Humidity), this calculator uses 25 Celsius and 50% humidity as the base. These are more typical values one might expect at a track meet. These conditions actually correspond to a density altitude of about 356 meters, which demonstrates the difference temperature and humidity can make.
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