1. Take a 10.0 g feather and down sample from the laboratory sample and place it in a 2000ml plastic jar, add 1000ml distilled water, and place it in a horizontal shaker for 30 min after sealing, the direction of oscillation is from the bottom of the bottle to Bottle mouth.

2. Filter the contents of the plastic jar with a standard sieve with an aperture of 0.1 mm (do not squeeze the filter), and collect the filtrate in a 2000 ml beaker

3. Pour the prepared sample liquid into the container of the transparency meter, slowly raise the position of the rubber hose, make the sample liquid enter the graduated cylinder through the hose, and make the liquid level gradually rise from the top of the cylinder Observe the black double cross line at the bottom until it disappears, then move the container down slightly to make the double cross line reappear and just be able to see clearly. Record the scale of the liquid level on the cylinder at this time, which is the sample Transparency

4. Measure the second sample according to the above-mentioned steps. The final result is the integer of the average of the two measurements, and the unit is millimeters.

5. Use a 1000mm transparency meter

6. The intensity of the light source should be above 600 Ix when measured under direct sunlight.

7. The height is 1000mm, including the cross black line