PBM28W by Ohara

Obsolete Unknown Environmentally Dangerous

PBM28W by Ohara is an obsolete optical glass. It transmits from 0.34 to 0.90 µm with an nd of 1.68893 and a Vd of 31.082901. It has medium thermal expansion (CTE of 8.6×10⁻⁶/K), good chemical resistance, and dangerous environmental properties.

Refractive Index vs Wavelength
Refractive Index Calculator
Valid range: 0.3–2.4 µm
dn/dλ vs Wavelength
dn/dλ Calculator
Valid range: 0.3–2.4 µm
Abbe Number Calculator
Transmission vs Wavelength
Transmission Calculator
Valid wavelength range: 0.340–0.900 µm
Optical Properties
Refractive Index (nd) 1.68893
Abbe Number (Vd) 31.082901
Dispersion Formula Schott
Wavelength Range 0.3 — 2.4 µm
$$n(\lambda) = \sqrt{2.75779 - 0.00873318\,\lambda^2 + 0.0303797\,\lambda^{-2} + 0.0011503\,\lambda^{-4} - 1.91678 \times 10^{-5}\,\lambda^{-6} + 7.47454 \times 10^{-6}\,\lambda^{-8}}$$
Thermal Properties
TCE -30/70°C (10-6/K) 8.6
TCE 100/300°C (10-6/K) 9.4
Thermal Conductivity (W/mK) —
Heat Capacity (J/gK) —
$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[8.284 \times 10^{-6} + 2(0)\,\Delta T + 3(0)\,\Delta T^2 + \frac{0 + 2(0)\,\Delta T}{\lambda - 0}\right] \Delta T = T - T_0, \quad T_0 = 25\,°\text{C}$$
Physical Properties
Density (g/cm³) 4.22
Relative Cost —
Mechanical Properties
Young's Modulus (GPa) —
Poisson's Ratio —
Knoop Hardness (kgf/mm²) —
Chemical Resistance
Climatic Resistance —
Stain Resistance —
Acid Resistance 2
Alkali Resistance —
Phosphate Resistance 2
Similar Glasses (Other Manufacturers)
Glass Manufacturer nd Vd Compare
D-ZF10 CDGM 1.68893 31.077677
K-SFLD8 Sumita 1.68893 31.1
FD8 Hoya 1.688931 31.158857
MP-FD80 Hoya 1.68893 31.16
M-FD80 Hoya 1.68893 31.16
E-FD8 Hoya 1.68893 31.16
MC-FD80 Hoya 1.68893 31.16
H-ZF10 CDGM 1.68893 31.16057
SF8 Schott 1.688932 31.176063
ZF10 CDGM 1.688934 31.184753
Similar Glasses (Ohara)
Glass Manufacturer nd Vd Compare
PBM28 Ohara 1.68893 31.082901
S-TIM28 Ohara 1.688931 31.07545
L-TIM28 Ohara 1.689479 31.023399
L-TIM28P Ohara 1.694529 30.655992
S-TIM35 Ohara 1.698947 30.127865
PBM35 Ohara 1.698947 30.121211
S-TIM25 Ohara 1.6727 32.099206
PBM25 Ohara 1.6727 32.101636
S-TIH20 Ohara 1.70585 30.244176
PBM39 Ohara 1.666799 33.046816
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