![ashrae psychrometric chart si big ashrae psychrometric chart si big](https://www.ohio.edu/mechanical/thermo/Applied/Chapt.7_11/Psychro_chart/psychro_chart.gif)
In practice this is the reading of a thermometer whose sensing bulb is covered with a wet sock evaporating into a rapid stream of the sample air (see Hygrometer). Wet-bulb temperature (WBT) is that of an air sample after it has passed through a constant-pressure, ideal, adiabatic saturation process, that is, after the air has passed over a large surface of liquid water in an insulated channel. The SI units for temperature are kelvins or degrees Celsius other units are degrees Fahrenheit and degrees Rankine.
![ashrae psychrometric chart si big ashrae psychrometric chart si big](https://www.ohio.edu/mechanical/thermo/Applied/Chapt.7_11/Psychro_chart/psych_ex10.1.gif)
It is typically plotted as the abscissa (horizontal axis) of the graph. The parameters are:ĭry-bulb temperature (DBT) is that of an air sample, as determined by an ordinary thermometer. It depicts these parameters and is thus a graphical equation of state. The ASHRAE-style psychrometric chart, shown here, was pioneered by Willis Carrier in 1904.
ASHRAE PSYCHROMETRIC CHART SI BIG HOW TO
How to read the chart: fundamental examplesĪ psychrometric chart for sea-level elevation TerminologyĪ psychrometric chart is a graph of the thermodynamic parameters of moist air at a constant pressure, often equated to an elevation relative to sea level.