Copkim 7.87 Inch Plastic Secchi Disk Set Secchi Disc with Black and White Quadrants, Steel Cone, Holding Line and 100 ft Tape Measure for Clarity Measurements

• Comprehensive Package: every purchase of the set includes the items you need for water clarity measurements; The package contains 1 piece of Secchi disk, 1 roll of holding string, 1 piece of cone weight, and 1 piece of tape measure; This ensures that you have tools to accurately measure both fresh and seawater transparency
• Ideal Size: bearing a diameter of around 7.87 inches/20 cm, the Secchi disc is suitably sized for efficient visibility under water; Meanwhile, the tape measure features a measurement of about 100 ft/ 30 meters, and the rope is about 16.4 ft/ 5 meter long, measurements that allow ample depth tolerance for deep water clarity measurement without hindrance
• Quality Materials: the acrylic Secchi disc, the pivotal piece, is made from acrylic which ensures its resilience, lightweight and portable; The cone, designed to weigh down the disk, is crafted from stainless steel ensuring its longevity, hard to rust; The holding string is made from robust polymer to handle the disk and cone weight without elasticity, hard to tear and sturdy for long time use
• Freshwater Measuring: use the black and white side, and when the water surface is stable on an unclouded day, lower the acrylic Secchi disk into the water with a holding rope until the disc can hardly be seen from above; Measure the length of the rope immersed in water, repeat it several times, and get the average to get freshwater clarity
• Saltwater Measuring: use the pure white side, at the backlight of the main deck, put plastic Secchi disc into the water, and sink to a depth just out of sight; Then slowly lift the rope until the dish is faintly visible, read the mark of the rope on the water surface, repeat for 2 or 3 times and take the average to get observed clarity; Read the mark of the rope at the crest and trough respectively when wavy, if the inclination angle exceeds 15, the depth should be corrected

Features: Prior to heading out to sea, it's important to check the robustness of the string that holds the Secchi disk. It should be pre shrunken by soaking it in water, then tightened and dried. Regular checks and corrections should be applied during use. The set is easy to maintain. After each observation, simply wash the disk with fresh water and soak the rope in fresh water before drying and storing it. Ensure the plate is always kept clean. If the paint falls off or gets dirty, it should be repainted. This set is a practical tool for water clarity tests. With the Secchi disk set, you can measure the transparency of both fresh and salt water. It is ideal for hydrologists, marine biologists, environmental scientists, and water enthusiasts alike, and can be applied for hydrological research, environmental observation, aquatic farming and other fields. Specifications: Material: Disc material: acrylic Cone material: stainless steel String material: polymer Color: Disc color: black and white Size: Disc size: about 7.87 inches/ 20 cm in diameter Tape measure size: about 100 ft/ 30 meter measurement Rope length: about 16.4 ft/ 5 meter Package includes: 1 x Secchi disk 1 Roll holding string 1 x Cone weight 1 x Tape measure Notes: Manual measurement, please allow slight errors on size. The color may exist a slight difference due to different screen displays. Winding risk may exist, keep away from kids under 3 years old. Attach the string or tape measure to the disc for measuring. A clip is equipped for attaching tape measure. The observation of seawater transparency is only carried out in daytime, and the observation place should be in the back of the sun, and the influence of sewage discharged from the ship should be avoided during observation.