What you need The -clutch psychrometer is used to measure the relative humidity. This is one of the simpler designs of psychrometers available on the market. It consists of two thermometers, a wet bulb and a dry bulb. These are attached to a frame that has a chain or light chain in the middle.
What you need
The loop psychrometer is used to measure relative humidity. This is one of the simpler designs of psychrometers available on the market. It consists of two thermometers, a wet bulb and a dry bulb. These are attached to a frame that has a chain or light chain in the middle. If you use it, you must swing the instrument in the air. It allows you to predict weather patterns and is also useful if you keep indoor plants. Here are steps for using the instrument.
Step 1 – Assemble the psychrometer
Tape the wet bulb and the dry ball to a frame with tape. Keep enough space between the thermometers so that no collisions occur when the frame is swiveled. Make sure the lights are hanging on the bottom. The numbers on the thermometers should be visible to allow reading with ease. Attach a string around the center of the frame.
Step 2 – Record readings
Record the temperature displayed on both thermometers in your chart. You should get the same number for both. If you register different temperatures, you will get inaccurate results when calculating humidity.
Step 3 – Prepare the wet pear
Thoroughly saturate the fabric with distilled water. Wrap it around the pear of one of the thermometers. Use rubber bands to secure both ends of the fabric. Make sure that the other lamp stays completely dry.
Step 4 – Panning the psychrometer
Apply the instrument by hand in a circular motion. Stop the activity for one minute and then stop the swinging. First note the wet bulb temperature, followed by the dry bulb. Start the swing activity again and after another minute, stop to measure both values. Always take the reading from the wet bulb before the temperature starts to rise. Do not pan for more than 3 minutes as the wet tissue dries out. As a result, the wet bulb temperature increases considerably and provides inaccurate moisture readings.
Step 5 – Final Readings
No more planning is required if you register the same reading from the wet lamp for 2 to 3 consecutive periods. Draw the final temperatures to the nearest 0.1 degrees. The temperature has reached its lowest end because the air is saturated with moisture. This equilibrium state prevents vaporization from taking place from the wet bulb. The relative humidity can then be calculated from the psychometric table using all the measurements obtained.
- Make sure your hands are clean when handling the instrument. Dirt or grease affect the accuracy.
- Body heat and moisture can affect the readings. It is best to keep the instrument at arm’s length as you begin to swing it.
- Avoid touching the bulb ends with your fingers when reading. Body heat leads to wrong temperature rises. It is also important that you record readings as soon as the swing stops. If you plan too much time, temperatures start to rise. This will give you an inaccurate humidity in the calculation.