For testing the absence or purity of gas when purging gas lines. Measurement ranges: - CH4: 0-100 Vol.% methane - O2: 0-25 Vol.% oxygen (optional) Resolution: - CH4: 0.1 Vol.% - O2: 0.1 Vol.% The option can only be ordered in combination with the Sensor Array Option (282102) or Dual IR Sensor Option (282103) and the Pump Option (282100).