The refractive index(nd) of H-PK71 is 1.56910 while the abbe number(υd) is 71.30. H-PK71 glass is the special dispersion glass and has the relative negative dn/dt coefficient compared with the products in the same series.
Glass name | H-PK60 | H-PK62 | H-PK63 | H-PK65 | H-PK71 | |
nd | 1.59350 | 1.61800 | 1.60300 | 1.62000 | 1.56910 | |
υd | 67.00 | 63.39 | 65.44 | 63.88 | 71.30 | |
△Pg,F | 0.0039 | 0.0012 | 0.5372 | 0.0045 | 0.0213 | |
dn/dt coefficient | dn/dt | -1.7 | -2.3 | -3.4 | -2.9 | -9.7 |
(0~20℃) | ||||||
CTE | α | 87 | 94 | 93 | 103 | 128 |
Abrasiveness | FA | 299 | 320 | 351 | 315 | 435 |
Density(g/cm3) | ρ | 3.27 | 3.53 | 3.54 | 3.52 | 4.29 |
Water resistance | DW | 1 | 1 | 1 | 1 | 1 |
DA | 4 | 4 | 4 | 4 | 2 | |
Alkali resistance | ROH | 1 | 1 | 2 | 1 | 1 |
Phosphate resistance | RP | 2 | 2 | 2 | 2 | 2 |
Coloration | λ80/λ5 | 340/265 | 360/280 | 345/275 | 365/295 | 330/275 |
