Measuring range: 0-100 (salt content); 1.000-1.070 (specific gravity)0100, minimum scale is 1 Measurement on 2 scales: Density (D 20/20) and parts per thousand and replace your poor quality and hard to read hydrometer Multiple applications: The refractometer is widely used for concentration management in fisheries, seawater used in fish farms, seawater or artificial water used in aquariums, brine used for fish storage, etc. Operation method: 1. Open the cover and wipe the detection prism carefully with a soft cloth. 2. Drop distilled water on the prism, turn the zero adjustment screw to adjust the dividing line to 0% of the scale, and then wipe dry. 3. Drop the solution to be tested on the prism, close the cover to prevent air bubbles, and spread the solution on the prism surface. 4. Point the light entrance plate of the instrument at the light source or a bright place. Observe the field of view through the eyepiece. Turn the eyepiece adjustment knob 5 to make the field of view blue. Tournez la molette de rglage de l'oculaire 5 pour rendre le champ de vision bleu. The white dividing line is clear, and the scale value of the dividing line is the measured value of the solution. Scope of application: marine, marine aquaculture, food processing, etc. Fully EquippedRefractometer*1, wiping cloth*1, straw*1, English manual*1, screwdriver*1, packing box*1 Delivery quantity: 1 piece set