These Nessler tubes are ideal for color comparison.
Features & Benefits
Manufactured from borosilicate glass 3.3
Shadowless bottom of each tube transmits undistorted light
Rings and legend are durable white ceramic enamel which correspond with specific volumes of liquid
Graduated ring scale of any of the tubes within a matched set will not vary from that of any other tube within the set by more than 1.5 mm for the 50 mL and 2.0 mm for the 100 mL sizes
The 50 mL size is specifically mentioned by the American Public Health Association in Standard Methods for the Examination of Water and Waste Water