ZAB25
中性暗色玻璃
photography
general-optics
2mm
光谱透过率曲线
曲线依据原厂样本手工描点还原，仅供选型参考，最终以实测报告为准。
技术要求
| 厚度 | 2mm |
| 平均透过率(标准) | 25% |
| 公差范围 | 18.0~32.0% |
| Qz | ≤6.0% |
国内外牌号对照
五机部
AB6
苏联(原)
HC8
SCHOTT
NG5
HOYA
ND-25
物理特性
| 折射率 Nd | 1.502 |
| 线膨胀系数 α | 65×10⁻⁷/°C |
| 转变温度 Tg | 469°C |
| 软化温度 Ts | 582°C |
| 密度 S | 2.41 |
| 耐酸性 DA | 5 |
| 耐水性 DW | 3 |
色度值 (x, y, Y)
| A | x=0.442 y=0.408 Y=25.7 |
| D65 | x=0.308 y=0.327 Y=25.4 |
气泡 C-B
条纹 4
应力 3
Source catalogue's 中性暗色玻璃特性 (Neutral Density Glass Characteristic) table header appears verbatim on both the neutral-grey page (96-97) and this neutral-density page (98-99) — likely a copy-paste artifact in the original PDF. Family grouping (neutral-grey vs. neutral-density) follows the catalogue's table of contents and the ZAB code progression rather than the repeated table header. Re-digitized against the clean sequential-page scan; curve reads genuinely ~0% from 200-290nm (UV cutoff) rising to ~44% at the 2500nm right edge, lowest of the ZAB25/30/50/65/70 family as expected from its 25% average-transmittance rating.