Wet-Bulb Temperature Calculator

Calculate Wet-Bulb Temperature



Formula

To calculate the Wet-Bulb Temperature (TW):

\[ TW = T * \arctan\left[0.151977 * (\sqrt{rh + 8.313659})\right] + \arctan(T + rh) - \arctan(rh - 1.676331) + 0.00391838 * (rh)^{1.5} * \arctan(0.023101 * rh) - 4.686035 \]

Where:

What is Wet-Bulb Temperature?

Wet-bulb temperature is a meteorological parameter used to measure the cooling effect of evaporation on the human body. It is determined by wrapping a wet cloth around the bulb of a thermometer and measuring the temperature drop caused by the evaporation of water from the cloth. This measurement provides valuable insights into the potential health risks associated with heat stress and the effectiveness of various cooling methods.

The human body relies on evaporative cooling through sweat evaporation to maintain a stable internal temperature. When the air becomes saturated with moisture, the evaporation process slows, and the body’s ability to cool itself becomes compromised. Consequently, high wet-bulb temperatures indicate reduced evaporative cooling efficiency and increased risk of heat-related illnesses.

Example Calculation 1

Let's assume the following values:

Using the formula:

Step 1: Calculate the intermediate values:

\[ TW = 30 * \arctan\left[0.151977 * \sqrt{70 + 8.313659}\right] + \arctan(30 + 70) - \arctan(70 - 1.676331) + 0.00391838 * 70^{1.5} * \arctan(0.023101 * 70) - 4.686035 \]

Step 2: Calculate the Wet-Bulb Temperature:

\[ TW \approx 26.45°C \]

The Wet-Bulb Temperature is approximately 26.45°C.

Example Calculation 2

Let's assume the following values:

Using the formula:

Step 1: Calculate the intermediate values:

\[ TW = 25 * \arctan\left[0.151977 * \sqrt{50 + 8.313659}\right] + \arctan(25 + 50) - \arctan(50 - 1.676331) + 0.00391838 * 50^{1.5} * \arctan(0.023101 * 50) - 4.686035 \]

Step 2: Calculate the Wet-Bulb Temperature:

\[ TW \approx 22.15°C \]

The Wet-Bulb Temperature is approximately 22.15°C.