Draft email to hydrophobic coating vendors...

We are assessing feasibility of hydrophobic and self-cleaning coatings for a new product which will contain approx. 50 scientific instruments for outdoor environmental analysis.

Coating will be applied to the exterior of an optically transparent glass or plastic dome which houses a hyperspectral camera sensitive to wavelengths of 165 to 1100 nm. Any transmittance reduction or optical artefacts caused by coating should be minimal across the operational temperature range of -40 to +85 ℃.

Coating should protect the dome from:

• Weather extremes (frost, ice, rain, hail, snow, high wind)
• Salt-water exposure
• Dust, plant sap/resin, oil residues, pesticides

Product is designed to provide maintenance-free operation for long periods of time (minimum 1 year, ideally 5+ years). The product lifespan is 10+ years; coating maintenance or re-application, if required, would be performed on-site by the end-user. Long-lasting coatings are preferred, even at the expense of lower performance.