actuall humidity is given as the amount of water. use a table stating how much water the air can hold at the given temp, this is your 100% humidity. now calculate howw much you got and that would be relative humidity
Answer:
To calculate relative humidity you need a wet bulb and a dry bulb thermometer and a psychrometric chart (a graph of the physical properties of moist air at a constant pressure). The chart graphically expresses how various properties relate to each other.
You don't.
Humidity and temperature are not the same thing. Humidity will change with temperature however. The hotter the air is the more moisture it can hold, at 100% humidity the air can hold no more moisture. let's say it is 20C and 100% humidity. If the temperature then climbs to 30C the humidity will drop as the air's capacity to hold moisture has increased.
Relative humidity is the ratio of the actual humidity and the humidity when the air is saturated with water vapor. One way to measure relative humidity is with a psychrometer. A psychrometer is an instrument that uses the difference in readings between two thermometers, one having a wet bulb and the other having a dry bulb, to measure the moisture content or relative humidity of air. When air is saturated, the bulbs have the same temperature. When it is less than saturated, the moisture around the wet bulb evaporates, cooling the wet bulb until it is cooled to the temperature where the concentration of water vapor in the air would saturate air at that temperature.
You must have another piece of information (in addition to temperature), to compute relative humidity. The other piece of information can be dew point, specific humidity, vapor pressure, heat index, or wet bulb (vs dry bulb) temperature, or dry bulb (vs wet bulb) temperature. The formulas for computing these values are part of the field known as psychrometrics, and note the spelling-- psychro (with an "r"), not psycho
The heat index is an index that combines air temperature and relative humidity in an attempt to determine the human-perceived temperature. The actual equation for the heat index is Heat Index = -42.379 + (2.04901523 x T) + (10.14333127 x R) - (0.22475541 x T x R) - (6.83783x10-3 x T2) - (5.481717x10-2 x R2) + (1.22874x10-3 x T2 x R) + (8.5282x10-4 x T x R2) - (1.99x10-6 x T2 x R2) In this equation T = Temperature in F and R = Relative Humidity in %.
Dew point is calculated by how much moisture and humidity is in the air. The dew point is calculated with a barometer.
If H = relative humidity,
T = air temperature in degrees C, and
D = dew point in degrees C,
H = e^(17.27 * (T * (237.7 + D) / (237.7 + T) - D) / (D - 237.7))
mass of vapour pressure(g)/mass of air(kg)
Relative humidity indicates how near the air is to saturation, while mixing ratio shows the actual quantity of water vapor in the air.
relative humidity
measure relative humidity presure and new point
Relative humidity.
30 to 50% of Relative humidity - the relative part of relative humidity being relative to the temperature.
relative humidity
Humidity is the amount of water vapor at any given time and relative humidity is the amount of water vapor in the air compared to the greatest amount it can hold at that air temperature.
Because it is relative to temperature!
Relative humidity indicates how near the air is to saturation, while mixing ratio shows the actual quantity of water vapor in the air.
Relative humidity becomes the ratio between the actual amount of water vapor present to the capacity that the air has at a particular moment. Just to be an optimist, if the glass is half-filled, the relative humidity is 50 percent. If the glass is three-quarters filled, the relative humidity is 75 percent.
relative humidity
Because it is relative to temperature!
relative humidity
One can calculate the absolute humidity (AH) from the relative humidity (r) using three equations: (1) the equation for mixing ratio, (2) an equation for relative humidity expressed in terms of mixing ratio, and (3) the Clausius-Clapeyron equation, which relates saturation vapor pressure to temperature. The result of combining the three equations is: AH = (1324 r/T) [exp {5417.75 (1/273 - 1/T)}] where AH is expressed in grams per cubic meter, T is temperature in Kelvin, r is relative humidity (range is 0 to 1), and the relation holds true for T>273. For T<273, replace 5417.75 with 6139.81.
HR= actual vapor pressure/ saturation vapor pressure
measure relative humidity presure and new point
This is called relative humidity. It is the ratio between the actual humidity, and the humidity for saturated air - that is, the maximum amount of water air can hold. This saturation point is dependent on temperature.