Consists of a probe station, onto which samples can be mounted. The size of the samples is typically some centimeters in diameter. The samples can be connected electrically for sensor measurements with micromanipulators that are part of the probe station. 

A large variety of gases can be tested. The gas bottles are kept in a special gas closet and the entire sensor set-up is electrically protected by a Faraday cage. It is mounted into a fume-hood. Highly sensitive source meters (Keithley, Agilent) for electrical measurements are available.