GoodsBazaar Refractometer 0-32 with ATC - Digital for Beer Wine Brewing, Brix 0-32% Manual Laboratory Refractometer

A traditional handheld refractometer is an analog instrument for measuring a liquid's refractive index. It works on the critical angle principle by which lenses and prisms project a shadow line onto a small glass reticle inside the instrument, which is then viewed by the user through a magnifying eyepiece.