A very low attenuation fiber-optical sensor switch (LAFOSS)

For multiple sensor oxygen measurements in the gas phase of experimental columns filled with pyrite bearing sediments an automated switch was constructed which allows to connect one MICROX 1 optical oxygen measurement system to 12 optodes. Since our switch simulates the manual connection of the optode ST connector to the ST–ST coupler at the instrument front panel the attenuation of the signals introduced by the sensor switch is as low as 0.2 dB compared to the single sensor system. First measurements using this low attenuation fiber-optical sensor switch (LAFOSS) for the determination of oxygen diffusion in the vadose zone of sediments are presented.