Use a calculator to determine the density of water vapor under a given set of circumstances. Find the variables for the following formula, which is based on the ideal gas law:
Pw = 0.0022pw / T
Find the value of pw, which is equal to the partial pressure of water vapor and is measured by Pa, N/m x m. Determine the value for T, which is equal to the absolute dry bulb temperature and is measured in Kelvins. Use these figures to find the density of water vapor, which is measured in kg/m cubed. Write these values down on a piece of paper and use them in the next step.
Use a calculator to multiply the value you found for pw by 0.0022. Enter the result into your calculator and press the divide ( / ) button on your calculator to divide the result by the value that you found for T. Write down the result, which will equal the water vapor density given the variables you entered.