Optical Glass Physical Properties
Optical glass physical properties
1: Refractive index (ND):
The refractive index of the glass is determined by the characteristic line D = 589.3 nm of the sodium element, denoted by ND.
2: specific gravity (s):
Determination of glass specific gravity by hydrostatic weighing method.
3: chromaticity value (x, y, y):
The chromaticity values of the glass under A and D65 standard light source illumination were determined according to the method specified in the International Commission on Illumination (CIE) 1931 and 1964.
4: Thermal characteristics:
When the glass temperature rises by 1 ° C its relative change in length.
5: transition temperature (Tg):
When the amount of glass swelling occurs suddenly, the corresponding temperature is the sample transition temperature. At this temperature, the viscosity of the glass is close to 10 13 Pa.
7: softening temperature (Ts):
When the physical properties of the glass are drastically changed, the amount of dilution is also close to zero (the softening temperature of the glass, where the viscosity of the glass approaches 10 11 Pa / sec).
8: color temperature conversion ability (V):
Color temperature glass is divided into two categories: warm glass and temperature glass, the conversion capacity to Milder (Mired) to express the value.
Rose color glass was blue, grade SSB, its Milford negative. Drop color glass was amber, grade SJB, its Milford positive value.