A TEI instrument was installed at Arrival Heights to monitor boundary layer concentration of surface ozone levels with an ultraviolet absorption measurement. Ambient air is pumped through a cell and the intensity of ultraviolet light shining through this cell from a mercury lamp is measured. Periodically the airflow is diverted to a chemical filter that removes ozone from the air and the lamp's intensity measured as a control to ensure data consistency. The instrument has its own data logging system that records ozone concentrations.
The data are processed directly by instrument and recorded as ozone concentrations measurements. The data is available online via the ftp site and held intenally by NIWA and NOAA. Please contact the investigator for further information.