Protective glass is used for details, protecting device from dirty, mechanical damages, dust and liquid at temperature from -60^oC to +60^oC.

1. Glass is produced with flat or spherical surface, round, figured, rectangular.
2. Glass can be made on customer’s working drawing.
3. Glass is manufactured with polished and unpolished surface.
4. Glasses are of equal thickness.
5. Coefficient of general transmission for thickness
   from 2,0 to 2,5 мм — 87%
   from 3,0 to 4,0 мм — 85%
   from 5,0 to 6,0 мм — 84%
6. Protective glass is chemically stable.

Colorless glass is used for gas-masks and protective eye glasses, preventing eyes from wind, dust, fragments, chips and splashes of non-aggressive liquids.

1. Glass is round or fashioned. It is made of sheet glass.
2. Light transmission coefficient is not less than:
   0.90-for one layer gas-mask
   0.87-for one layer glass for protective eye glasses with round and fashioned shape.

   Glass is colorless.

   Glass is mechanically strong.

   Glass is moister resistant and heat proof.

Hardened glass is applied for gas-masks and protective eye glasses, preventing eyes from wind, dust, fragments, chips and splashes of non-aggressive liquids.

1. Hardened glass is produced with bent surface. Glass is hardened with ion change methods.
2. Light transmission coefficient has to be not less than 0.87
3. Glass is colorless.
4. Glass is mechanically strong.
5. Sizes (in mm) are coordinated with the customer.

Glass is made for protection of devices.

1. Glass is produced flat and with spherical surfaces.
2. Shape, size, sphere height, edge treatment type can be made on customer’s request.
   

   Size, mm	Tolerance, mm
   diameter	thickness 3mm	thickness from 3 to 5 mm
   up to 100	-0,5	-0,6
   from 100 to 250	-0,8	-0,9

3. Glasses are of equal thickness.
4. General light coefficient has to be for glass not less than:
   thickness to 2 mm — 89%
   thickness 2.0-2.5 mm — 87%
   thickness 5.0-6.0 mm — 84%
5. Glass is mechanically strong and thermal stable.
6. Glass does not change translucent in temperature range from -60^оС to +80^оС.