1. Measuring relative humidity
Use a dry bulb, a wet bulb and a table to determine the % of water
Vapor the air contains. These instruments are called a psychrometer.
psychrometer

2. Measuring Humidity Lab Activity
Use the dry-bulb thermometer to measure and record the room temperature.
Wrap gauze around the bulb of the 2nd thermometer and fasten it with a rubber band. Dip the gauze-wrapped wet-bulb into room temperature water.
Fan the bulb until the temperature stabilizes. Record the temperature.
Calculate the difference between the dry-bulb & wet-bulb temperatures.
Use Appendix A (pg 704) in the textbook to determine the Relative humidity in the location you tested.
Pre-Lab and Lab overview
Choose a location to measure the relative humidity. Record the areas where your classmates will be testing.
On the back, make a prediction where you believe the highest and lowest relative humidity will occur. (#1 on back)
Run the lab and record your measurements and error on the back of this sheet (#2).
Consider and write possible errors in your measurements.
5. Compare your results with the class and on the back write where the actual high and low occurred. Why do you think this was? (#3 on back)
Hallway
door
Backroom

3. Highest relative humidity: Lowest relative Humidity: 2. Data
Prediction
Where in the testing area do you think the highest and lowest relative humidity will occur?
Highest relative humidity:
Lowest relative Humidity:
2. Data
Record your obtained data.
Dry bulb temp. _______________
Wet bulb temp. ______________ Relative Humidity _______%____
Difference _______ ___________
3. Error
During your testing for relative humidity, write notes concerning error within your experiment.
4. Results
After comparing your results with the class, where was the lowest and highest humidity's in the testing area? H: L:
5. Reasoning:
Why do you think the high and low were recorded where they were?