Our refractometer can measure the salinity quickly and accurately, ideal for agriculture, industry and research application, such as mariculture, fish culture, aquarium, marine survey, water quality monitoring, manufacture of normal saline, salinity measurement in food processing etc. Features: The handheld refractometer is easy to use and can measure the salinity quickly. Aluminum construction is lightweight, wear resistant and durable. Features automatic temperature compensation and high accuracy. The rubber handle is non-slip and comfortable to grip. Professional, widely used in food industry, aquaculture, aquarium, sea water detection, etc . Operating procedures: 1. Open the cover and clean the detection prism with a soft cloth. 2. Take the test solution, place it on the detection prism, gently close the cover to avoid air bubbles, and make the solution spread over the prism surface and put the instrument into the light plate. 3. Align the light source or the bright area, observe the field of view through the eyepiece, and turn the eyepiece to adjust the handwheel. 4. Make the blue-white boundary of the field of view clear, and the scale value of the boundary is the concentration of the solution. Specification: Condition: 100% Brand New Material: Aluminum, Rubber Color: Shown as Picture Measuring Range: 0-100% Salinity Accuracy: ±1% Length: approx. 19cm/7.48in Weight: approx. 241g/8.5oz Package list: 1 * Refractometer 1 * Pipette 1 * Screwdriver 1 * Wiping Cloth 1 * Instruction Note: 1. Please allow small size error due to manual measurement. Thanks for your understanding. 2. Monitors are not calibrated same, item color displayed in photos may be showing slightly different from the real object. Please take the real one as standard.