The refractive index of a solution containing sugar is in proportion to its sugar concentration. The model 500 uses this principle, where a transmitting system is applied, to obtain a high contrast in the field of view. 

*Verification with the 10% Sucrose Solution (RE-110010), 20% Sucrose Solution (RE-110020), 30% Sucrose Solution (RE-110030), 40% Sucrose Solution (RE-110040), 50% Sucrose Solution (RE-110050) or 60% Sucrose Solution (RE-110060).