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Humidity is the amount of water in the air at any given time. Outdoors, one of the best ways to determine humidity level is with a hygrometer. The wet and dry bulb method can also work outdoors if a hygrometer is not available. Indoors, one of the best ways to determine humidity level is for a person to recognize the signs, such as excessive static electricity, condensation on the inside of windows, musty smells, and stains on walls or ceilings.
A hygrometer measures the humidity level of its surroundings. Hygrometers typically are available wherever room thermometers can be purchased. Often, hygrometers and thermometers are combined into one piece of equipment. A hygrometer can take up to two hours to provide an accurate measurement of humidity. Calibration is also an important factor when using a hygrometer.
The wet and dry bulb method uses two mercury thermometers where a wet towel is wrapped around the bulb of one of the thermometers. After waiting for the temperature levels to settle, the dry bulb and wet bulb temperatures can be taken and used to calculate the relative humidity. A quick Internet search for "wet and dry bulb humidity" will provide a number of calculators that can be used for this. This method is not as accurate as a hygrometer but can be a good stand in.
Humidity levels in a house are more important than many people realize. Levels that are too low can cause chapped lips and other symptoms, and humidity levels that are too high can harbor dangerous mold and fungus. One of the best ways to determine humidity level is for a person to know the signs of high and low humidity.
The easiest way to tell if the humidity inside a house is too high is checking the windows for condensation on the inside of the window. If this occurs on a regular basis, it means the humidity level is too high — bathrooms usually are susceptible to this type of humidity. Exhaust fans can be used before, during, and after a shower or bath to help disperse and lower the humidity level. Other signs of high humidity are musty smells, wet stains on walls or ceilings, and allergic reactions that could be the result of mold.
Different signs will occur if the humidity in a house is too low. These can include dry, chapped skin and lips, breathing problems, a scratchy throat, and excessive static electricity. A good indicator of excessive static electricity is hair standing on end after being combed or brushed.
If a person wants to use a hygrometer indoors, the hygrometer should typically be placed in the room that the inhabitants of the home spend the most time in, and kept away from sources of direct heat. It should be calibrated before use and re-calibrated periodically to ensure it remains one of the best ways to determine humidity level. Directions for calibration can usually be found in the owner's manual or with a quick Internet search.