Figure

Epoxy sealed

Ceramic sealed

Soviet style

British style

Insulation medium between contacts

Nitrogen, Hydrogen
Illustrate    ：
1、The contact is not affected by the environment;

2、Electric ionization can be high, not easy to generate arc；

3、Strong insulation performance.

Air
Illustrate    ：

1、Affected by the environment ；

2、Easy to generate arc；

3、Low insulation performance

Load voltage

High (Max 1500Vdc )
Illustrate    ：
Inert gas and magnetic blowout arcing

Low ( Generally 72Vdc )
Illustrate    ：
Magnetic blowouts only, arcing  ineffective

Volume

Small
Illustrate    ：
Due to the protection of inert gas, there is no need for the gap between the contact and the insulation distance

Large
Illustrate    ：
Air as insulating medium; needs to reserve a large contact gap and insulation distance

Reliability

High
Illustrate    ：
The contact is protected by inert gas and is not polluted. Its resistance is small with low temperature-rise ;no arc leaking .

Low
Illustrate    ：
Main contact exposure to air, there is a risk of arc leaking and contact fault.