Varnish Viscosity Tube
Flat-bottomed. With lines at 27mm, 100mm and 108mm from the outside bottom. For rough control work where bubble comparison is made to limit samples of known viscosity, reference ASTM D1545. Lines are durable white ceramic enamel. Manufactured from 51 expansion borosilicate glass conforming to USP Type I and ASTM E438, Type I, Class B requirements.