About the difference between wet bulb temperature and dry bulb temperature:
Wet and dry bulb temperature table: With a pair of side-by-side device, the shape of the same temperature meter, a measured temperature, called the dry bulb temperature table, the other bag has to maintain soaked distilled water of the skim gauze, called wet bulb temperature table. When the air is not saturated, the wet bulb needs to burn heat to reduce the wet bulb temperature. Meanwhile The wet bulb continues to gain heat from the air that flows through the wet bulb. When the wet bulb is consumed by evaporation and the heat obtained from the ambient air is balanced, the wet bulb temperature does not continue to decline, resulting in a wet-and-dry bulb temperature difference. The size of the temperature difference between wet and dry bulb is mainly related to the air humidity. The faster the moisture evaporates on the wet bulb surface, the more the wet bulb temperature drops, the greater the temperature difference between wet and dry bulb. Conversely, the greater the air humidity, the slower the evaporation of moisture on the wet bulb surface, the less the wet bulb temperature drops, the smaller the temperature difference between wet and dry balls. Of course, the temperature difference between wet and dry bulb is also related to other factors, such as Wet ball size, wet ball wetting method and so on. According to the temperature value of wet and dry bulb, and some other factors are taken into account, the air humidity at that time can be calculated theoretically. The wet and dry bulb thermometer is the main instrument for current humidity measurement, but is not suitable for use in low temperature (-10 ℃ or less).
ba--the difference between wet bulb temperature and dry bulb temperature