The automotive ADD501A Refractometer is designed for accurately measuring the strength of battery fluid, screenwash and antifreeze by measuring the refractive index of light passing through the mixture. With the indication of the percentage you may know at which temperature the fluid will be frozen for both propylene glycol and ethylene glycol. It can also be used for checking the strength of electrolyte solution battery. The instrument incorporates a display, subdivided into three scales, from which the values for the respective fluids can be read off (see illustration). The internal scale of this refractometer displays glycol freeze points in degrees Celsius. Auto Temperature Compensation (ATC) Automatic-temperature-compensation eliminates the need for measuring temperatures and applying a correc-tion factor, when taking readings. Both the range and response time of the temperature compensation are unsurpassed by any other instruments in the industry. Instruments without temperature compensation simply can’t measure up.
Check that the prism and lid of the instrument are clean. With the pipette supplied, place a drop of the fluid you wish to test on the prism, close the lid; this will disperse the fluid. Turn the eyepiece so that it is properly focused. Read off value on the corresponding scale – a pronounced LIGHT – DARK dividing line is displayed. On the completion of each test, carefully clean the prism with a dry cloth.