To find the relative humidity as a percentage from a dry and wet bulb thermometer, it is necessary to record these readings using two standard thermometers and a psychrometric chart. One thermometer measures the dry bulb temperature while the other measures the wet bulb temperature.Continue Reading
To take the wet bulb temperature, place a wet cloth around the bulb and record the temperature reading, which will be lower than the dry air temperature. Similarly, record the dry bulb temperature reading of the air and use the chart to find the relative humidity. A psychrometric chart has the dry bulb temperatures at its base, and the wet bulb temperatures are found on a curved line at the left of the chart. The point where the two readings intersect on this chart is the relative humidity in percent.
An example to find the relative humidity on this chart is using a dry bulb reading of 80 degrees Fahrenheit and a wet bulb reading of 67 F. This will give a relative humidity result of 50 percent.Learn more about Weather & Tides
A humidity level of about 45 percent is considered comfortable outdoors. Levels of humidity can vary from place to place. Humidity levels change according to seasons. Winters are dry and humidity is high in the summer.Full Answer >
High humidity is generally regarded as the dew point temperature being at or only a few degrees below the measured air temperature. Dew point is the temperature at which water vapor condenses on surfaces, such as when morning dew condenses on grass.Full Answer >
There are different tools available to help measure humidity, including a hygrometer, a hygrograph and a sling psychrometer. Each separate tool that measures humidity does so on a different scale.Full Answer >
A psychrometer uses two thermometers, one ordinary and one a wet bulb thermometer, to measure relative humidity. It is a type of hygrometer, and is an older version of the more modern devices that use electronic sensors to measure changes in electrical resistance.Full Answer >