... photocathode Diameter of 28.5mm(1.12 inch), nine stage, side-on photomultiplier tubes, borosilicate glass, double-alkali ... : Diameter of 28.5mm(1.12 inch), nine stage, side-on photomultiplier tubes, borosilicate glass,double-alkali photocathode ... , using a specially designed anti-lag structure, with excellent output stability. Applicable technology areas: Spectrophotometer, colorimeter, dust meter, ...