Humidity
Humidity is the measurement of water vapour in the atmosphere and is measured using a hygrometer or wet and dry bulb thermometer. There are two parts to a wet and dry bulb thermometer, the dry bulb measures the air temperature and the wet bulb is covered with a damp cloth that is submerged in water. The wet bulb thermometer measures how dry the air is because the drier the air, the more water evaporates off the bulb, the lower the temperature reading goes. This indicates a higher humidity in the air. Similarly, the less water that evaporates, the more alike the wet and dry bulb thermometers are reflecting a low humidity.
Materials:
- Wet and dry bulb thermometer
- Water
- Designated place of hanging
Method:
1. Fill the hygrometer water container with water.
2. Hang the wet and dry bulb thermometer on a tree or wall for 5-10 minutes out of direct sunlight.
3. Record the dry bulb temperature.
4. Record the dry bulb thermometer.
5. Subtract the dry bulb temperature from the wet bulb temperature. On the surface of the hygrometer find the reading of the wet bulb depression and the dry bulb temperature and find where they both meet. This reading will give you the relative humidity and percentage of water vapour in the atmosphere.
The relative humidity measured on this field study was 71% which was within the average range of 60-90%.
Materials:
- Wet and dry bulb thermometer
- Water
- Designated place of hanging
Method:
1. Fill the hygrometer water container with water.
2. Hang the wet and dry bulb thermometer on a tree or wall for 5-10 minutes out of direct sunlight.
3. Record the dry bulb temperature.
4. Record the dry bulb thermometer.
5. Subtract the dry bulb temperature from the wet bulb temperature. On the surface of the hygrometer find the reading of the wet bulb depression and the dry bulb temperature and find where they both meet. This reading will give you the relative humidity and percentage of water vapour in the atmosphere.
The relative humidity measured on this field study was 71% which was within the average range of 60-90%.