Αποτελέσματα Αναζήτησης
12 Μαΐ 2022 · The Rothfusz regression is not appropriate when conditions of temperature and humidity warrant a heat index value below about 80 degrees F. In those cases, a simpler formula is applied to calculate values consistent with Steadman's results: HI = 0.5 * {T + 61.0 + [(T-68.0)*1.2] + (RH*0.094)}
The formula below approximates the heat index in degrees Fahrenheit, to within ±1.3 °F (0.7 °C). It is the result of a multivariate fit (temperature equal to or greater than 80 °F (27 °C) and relative humidity equal to or greater than 40%) to a model of the human body.
The index that finds current favor in the U.S. is the Steadman heat index or simply heat index. It stems from the work of R.G. Steadman (1979a, R.G. Steadman 1979b), who investigated the perception of heat under a variety of meteorological conditions using extensive data on human physiology.
1 Οκτ 2013 · Extensive details are given in the original paper that developed the heat index (Steadman 1979a) to describe how physiological heat-regulation principles were used to incorporate both air temperature and moisture to determine heat index values for specific weather conditions.
The Heat Index (or apparent temperature) is the result of extensive biometeorological studies. The parameters involved in its calculation are shown below (from Steadman, 1979).
studies’ heat index algorithms generate values consistent with apparent temperature. Additionally, most different algorithms generate closely correlated heat index values.
HI is the heat index expressed as an apparent temperature in degrees F. If the RH is less than 13% and the temperature is between 80 and 112 degrees F, then the following adjustment is subtracted from HI: ADJUSTMENT = [ (13-RH)/4]*SQRT { [17-ABS (T-95.)]/17} where ABS and SQRT are the absolute value and square root functions, respectively.
