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Zinc Sulphide FLIR (Zinc Sulfide) (ZnS)

Zinc Sulphide FLIR (ZnS) Data Sheet     ♦ Zinc Sulphide FLIR (ZnS) Guide to Cutting

Zinc Sulphide FLIR (ZnS) MSDS

ZnS FLIR is used for IR windows and lenses in the thermal band (8 to 14 μm) as a tough front optic in thermal imaging systems, particularly those subjected to harsh environments. ZnS FLIR grade is harder than ZnS multispectral grade

Transmission Range : 1.0 to 13 μm
Refractive Index : 2.192 at 10.6 μm
Reflection Loss : 24.6% at 10.6 μm (2 surfaces)
Absorption Coefficient : 0.02 cm-1 at 3.8 μm
Reststrahlen Peak : 30.5 μm
dn/dT : +43 x 10-6/°C at 3.39 μm
dn/dμ = 0 : n/a
Density : 4.08 g/cc
Melting Point : 1827°C (See notes below)
Thermal Conductivity : 16.7 W m-1 K-1 at 296K
Thermal Expansion : 6.6 x 10-6 /°C at 273K
Hardness : Knoop 240 with 50g indenter
Specific Heat Capacity : 469 J Kg-1 K-1
Dielectric Constant : n/a
Youngs Modulus (E) : 74.5 GPa
Shear Modulus (G) : n/a
Bulk Modulus (K) : n/a
Elastic Coefficients : Noy Available
Apparent Elastic Limit : 103.4 MPa (15,000 psi)
Poisson Ratio : 0.29
Solubility : 65 x 10-6 g/100g water
Molecular Weight : 97.43
Class/Structure : Polycrystalline cubic, ZnS, F43m

To download this data or our MSDS safety data sheet as a pdf, please click on the links at the top of the page.  To expand the transmission graphs, please click on the image.

Click to access current Zinc Sulphide FLIR Windows
Click to access current Zinc Sulphide Lenses

µm   Noµm   Noµm   No
0.42    2.516 0.46    2.458 0.50    2.419
0.54    2.391 0.58    2.371 0.62    2.355
0.66    2.342 0.70    2.332 0.74    2.323
0.78    2.316 0.82    2.31 0.86    2.305
0.90    2.301 0.94    2.297 0.98    2.294
1.00    2.292 1.40    2.275 1.80    2.267
2.20    2.263 2.60    2.26 3.00    2.257
3.40    2.255 3.80    2.253 4.20    2.251
4.60    2.248 5.00    2.246 5.40    2.244
5.80    2.241 6.20    2.238 6.60    2.235
7.00    2.232 7.40    2.228 7.80    2.225
8.20    2.221 8.60    2.217 9.00    2.212
9.40    2.208 9.80    2.203 10.2    2.198
10.6    2.192 11.0    2.186 11.4    2.18
11.8    2.173 12.2    2.167 12.6    2.159
13.0    2.152 13.4    2.143 13.8    2.135
14.2    2.126 14.6    2.116 15.0    2.106
15.4    2.095 15.8    2.084 16.2    2.072
16.6    2.059 17.0    2.045 17.4    2.03
17.8    2.015 18.2    1.998

Zinc Sulphide is produced by synthesis from Zinc vapour and H2S gas, forming as sheets on Graphite susceptors. Zinc Sulphide is microcrystalline in structure, the grain size being controlled to produce maximum strength. Forward Looking Infra-Red (FLIR) grade, which is pale yellow and translucent in the visible, is used as deposited without further treatment. It is stronger than multispectral grade. Single crystal ZnS is available, but is not common.

ZnS oxidises significantly at 300°C, exhibits plastic deformation at about 500°C and dissociates about 700°C. For safety, Zinc Sulphide windows should not be used above 250°C in normal atmosphere.