Spark Gaps; Overvoltage Arresters Using Spark Gaps; Sparking Plugs; Corona Devices; Generating Ions To Be Introduced Into Non-enclosed Gases
G01N
Investigating Or Analysing Materials By Determining Their Chemical Or Physical Properties
H01L
Semiconductor Devices; Electric Solid State Devices Not Otherwise Provided For
C04B
Lime, Magnesia; Slag; Cements; Compositions Thereof, E.g. Mortars, Concrete Or Like Building Materials; Artificial Stone ; Ceramics ; Refractories; Treatment Of Natural Stone
F01N
Gas-flow Silencers Or Exhaust Apparatus For Machines Or Engines In General; Gas-flow Silencers Or Exhaust Apparatus For Internal Combustion Engines
