General operating conditions

0

Not protected

1

Protected against access to dangerous parts with the back of the hand.
Protected against solid foreign objects of 50 mm Ø

2

Protected against access to dangerous parts with a finger.
Protected against solid foreign objects of 12.5 mm Ø

3

Protected against access to dangerous parts with a tool.
Protected against solid foreign objects of 2.5 mm Ø

4

Protected against access to dangerous parts with a wire.
Protected against solid foreign objects of 1 mm Ø

5

Protection against access to dangerous parts with a wire.
Dust-protected. Ingress of dust is not prevented completely, although the quantity of dust able to penetrate is limited to such an extent that the proper function of the device and safety are not impaired

6

Protection against access to dangerous parts with a wire.
Dust-tight. No ingress of dust

0

Not protected

1

Protection against vertically falling water drops

2

Protection against vertically falling water drops when enclosure tilted up to 15°

3

Protection against spraying water. Water sprayed at an angle of up to 60° on either side of the vertical shall have no harmful effects

4

Protection against splashing water. Water splashed against the enclosure from any direction shall have no harmful effects

5

Protection against water jets.

6

Protection against powerful water jets.

7

Protected against the effects of temporary immersion in water.
Ingress of water in quantities causing harmful effects shall not be possible when the enclosure is immersed in water at a depth of 1 m for 30 minutes

Water vapor

unstable at temperatures > 100 °C

Sodium hydroxide solution
(ph value > 12)

stable at room temperature
unstable > 40 °C

Acetic acid

unstable

Argon (technically pure)

stable