Feature: 1. The refracting prism and the light entrance cover make the salinity measurement more accurate and better protect the surface of the detection prism with fine workmanship and exquisite appearance. 2. The non‑slip rubber cover handle, the non‑slip rubber cover handle made of environmentally friendly materials makes your operation more convenient. 3. The eyepiece reading hole, the eye reads through the eyepiece, the reading is fast, accurate and clear. The eyepiece adjustment hand wheel can be turned. 4. The refractometer is an optical instrument that can accurately measure the percentage concentration of salt in a solution through the principle of light refraction. 5. Made of high quality Aluminium materials, with functions of fast, accurate, light weight, small body and easy to carry. Specification: Condition: 100% Brand New Item Type: Refractometers Color: As Pictures Shown Material: Aluminium + RubberSize: Approx. 20x4cm/7.9x1.6inSuitable Pet Type: Sea water, fish tank, aquarium Function: Sea water tank optical salinometer/Refractometer Mainly Used for Measurement: Ornamental sea aquarium, marine fish breeding, etc., mechanical processing and food industry.Main Technical Parameters: Optical system magnification 3 times Measuring Range: 1.000-1.070, accurate to 0.1% Technical Principle: Refractometer is an optical instrument. Through the principle of light refraction, it can accurately measure the percentage concentration of salt in the solution. It is fast, accurate, light in weight, small in size and easy to carry. Scope of Application: This product is a combination of refracting prism + mirror plate + calibration bolt + optical system pipeline + eyepiece (vision adjustment ring). It is used to measure salt solutions, salt-containing food and sea water tanks, marine life breeding, aquariums In the fields of normal saline preparation and other fields, there are two unique scale lines that can directly read the specific gravity and concentration of the salt solution (in thousandths, the product has automatic temperature compensation function, which is particularly convenient for field use Usage: 1. Clean the detection prism and light entrance cover with mirror cleaning fluid, and wipe dry with a soft cloth. Hold the salt meter horizontally and open the light entrance cover. 2. Use a straw to suck a small amount of seawater to be tested and drop it on the detection prism Never extend the salinity meter directly into sea water. 3. Gently close the light entrance cover to avoid air bubbles from spreading over the surface of the detection prism. 4. Point one end of the salinometer detection prism at the light source and read through the eyepiece. Note: The refractive index is also affected by light sources of different wavelengths, so please read under natural light. The upper part of the eyepiece is blue. White/transparent under the scale. The reading at the location of the blue-white junction is the test result. Adjust the focus according to individual needs until the image in the eyepiece is clear. After use, clean the detection prism and the light entrance cover with mirror cleaning fluid, and dry it with a soft cloth. Calibration Operation: During regular calibration, please place the device in an environment of 25°C for 30 minutes to allow the salinometer to operate at a temperature close to the ambient temperature. 1. Remove the screw cap on the calibration screw. 2. Put a few drops of distilled water on the detection prism and turn the zero adjustment screw. 3. Adjust the dividing line to the position of 0% of the scale, and then wipe off the detection prism for detection.. Package List: 1 x Refractometers1 x Screwdriver1 x Straw1 x Mirror Wipes