The resulting indicated temperature is known as the wet-bulb temperature of the air sample. If the thermometer bulb is wrapped in a wick moistened with water and the process air is allowed to flow through the wick, evaporation of the water contained in the wick will lower the temperature of the thermometer bulb even though the dry-bulb temperature of the airstream remains the same. The specific humidity or humidity ratio of an air sample is the ratio of the weight of water vapor contained in the sample compared to the weight of the dry air in the same sample.ĭry-bulb temperature is the temperature of air as indicated by a standard thermometer. Robison, in Passive and Low Energy Ecotechniques, 1985 THERMODYNAMIC PROPERTIES OF AIR Alternatively, you can also find it from the mixing ratio of air.H.I. You can also use it to calculate the relative humidity if you know the dew point temperature.
If you would like to know more about the relative humidity formula, check out our dew point calculator. Remember that both temperature and wet bulb temperature in this formula are expressed in ☌! If you would like to use other units, you need to convert them to the Celcius scale before you start calculations. Rh% Relative humidity - a ratio of how much water vapor is in the air to how much it could contain at a given temperature. T Temperature - air temperature or dry-bulb temperature is the temperature given by a thermometer not exposed to direct sunlight. It might look intimidating, but don't worry - we do all the calculations for you. The wet-bulb calculator is based on the following formula: It loses its accuracy in situations where both moisture and heat are low in value, but even then the error range is only between -1☌ to +0.65☌. If the wet-bulb temperature exceeds 35 ☌ (95 ☏) for an extended period of time then people in the surrounding area are at risk of hyperthermia.Īlthough many equations have been created over the years our calculator uses the Stull formula, which is accurate for relative humidities between 5% and 99% and temperatures between -20☌ and 50☌. This causes our internal body temperature to rise. Our bodies sweat to cool off, but, because water evaporates slower in more humid conditions, we cool down a lot slower in humid conditions. As the humidity decreases, the wet-bulb temperature becomes lower than the normal air temperature.ĭata about the wet-bulb temperature is essential when it comes to preventing our body from overheating. When air is at its maximum (100 %) humidity, the wet-bulb temperature is equal to the normal air temperature (dry-bulb temperature). It includes a dry-bulb thermometer, a wet-bulb thermometer and a psychrometric chart - a graph that plots the relationships between the dry and wet-bulb temperature, relative humidity, and dew point at constant pressure.īy definition, wet-bulb temperature is the lowest temperature a portion of air can acquire by evaporative cooling only. This thermometer is part of a device called a psychrometer. It is instead the temperature read by a special thermometer that is wrapped in water-soaked fabric and ventilated.
Keep reading if you want to discover some wet-bulb applications, what the military benefits of the Wet-Bulb Globe Temperature, and what it has to do with our health - especially important in the context of this year's extreme weather conditions! If you want to find out more about our atmosphere, check out our heat index calculator and our air density calculator.ĭespite what you might think at first, wet-bulb temperature has nothing to do with light bulbs. You can use it to work out the wet bulb temperature with just two numbers: temperature and relative humidity. The wet bulb calculator operates on a simple principle. This tool will teach you about the wet bulb, and lets you estimate it's scale. And this is just the beginning of 2021's forecast heatwaves! What many people might fail to take into account when considering these temperatures and their impact on daily life, is the combined result of the heat and humidity - the wet bulb effect. With such striking examples as Canada recording its highest temperature to date, reaching 49.6 C, it's hard to deny something is "in the air". Climate change has never been as easily noticeable to the average person as today.