description:a refractometer is a device that allows you to determine the physical properties of liquids by measuring the refractive index at the interface.this allows you to determine:- battery charge level- freezing point of fluids based on propylene glycol or ethyl alcohol- freezing point of windshield washer fluid.professional refractometer for measuring operating fluids in passenger cars trucks and buses. It is designed to determine the freezing point of windshield washer fluid propylene glycol coolant and ethylene glycol coolant. It also provides the electrolyte density range.the kit includes a sampling pipette and a cleaning cloth. Everything is packed in a sturdy plastic box.how to use:measurement of fluid:- take a small amount of fluid using a pipette.- lift the diffusing plate and apply 2-3 drops of fluid to the device's prism.- lower the diffusing plate so that it evenly distributes the tested fluid across the prism surface. There should be no visible air bubbles which could falsify the measurement.- wait approximately 30 seconds for the fluid to reach the device's temperature and then aiming the diffusing plate towards the light source look into the eyepiece.if the image in the eyepiece is blurry adjust the focus by turning the focusing ring. The boundary between the dark and light areas will determine the properties of the fluid read on the appropriate scale.if testing battery electrolyte the reading should be taken on the scale marked with the battery symbol. The result is given in kg/l and the scale is additionally marked with battery charge levels. If the limit falls within the area marked good it means the battery does not require charging. fair means charging is not necessary yet but may be required soon. recharge means the battery requires charging.if a propylene glycol-based fluid is being tested the freezing point can be read on the scale marked propylene.if an ethyl alcohol-based fluid is being tested the freezing point can be read on the scale marked ethylene.if windshield washer fluid is being tested the freezing point can be read on the scale marked with the washer symbol.device calibration:note! calibration should be performed at an ambient temperature of 20 degrees c. Also make sure that the device has reached ambient temperature. Before each measurement check the accuracy of the measurement. To do this use distilled water and measure as described above. The boundary between the light and dark areas should align with the line marked waterline. if not align the calibration screw using the included screwdriver.a properly calibrated device should allow for measurements at ambient temperatures ranging from -10 degrees c to +50 degrees c.package contents:the refractometer should also include a pipette screwdriver and cloth.technical data:gross weight (kg): 0.2750