Wet bulb calculator now available as an app
TechnoAlpin's practical wet bulb calculators have served as useful aids to snow-making technicians for years. For iPhone users the calculator is now available as a free-of-charge app. Simply search for the "wet bulb" app online, download and use. To calculate the wet bulb temperature, rotate the temperature display dial to the current temperature. This in conjunction with the current humidity level then gives the wet bulb temperature. A calculator is naturally available for both Celsius and Fahrenheit temperatures.
The wet bulb temperature is the relevant temperature for snowmaking. It is a combination of air temperature in °C or °F and relative humidity as a %. It corresponds to the temperature shown by a thermometer when the bulb of mercury is wetted. If humidity is very low, the water quickly evaporates and extracts a lot of heat from the mercury column so that the thermometer indicates a temperature that is lower than the actual air temperature. Humidity has a much bigger influence on the wet bulb value. The more humid the air, the less additional humidity it can absorb and the colder it must be for snow crystals to form from the fine droplets of water. Conversely, the lower the humidity, the easier it is for water to evaporate from the surface of the atomized water and so cool the droplet.