The calibration was completed at the Kirtipur campus of Tribhuvan University near Kathmandu by an expert from International Ozone Services Inc. with support from the Vienna Convention Trust Fund through WMO. The instrument was installed in early 2001 and operated for two years, but had then been out of service until the expert visit in September 2006. The instrument required a new main power supply and reprogramming of its new electronics.

The calibration was completed at the Indonesian National Institute of Aeronautics and Space facilities in Bandung by an expert from International Ozone Services Inc. with support from the Vienna Convention Trust Fund through WMO. The instrument was installed in early 1995 and last visited in 2001, but had been out of service for the past four–five years. The instrument required a new power supply, microboard and ultraviolet filter in front of the photomultiplier tube to return it to service. The Indonesian National Institute of Aeronautics and Space supported the work.

Nine Dobson spectrophotometers from Algeria, Botswana, Egypt, Kenya, Nigeria, Seychelles and South Africa were sent to Dahab, Egypt, for intercomparison under the leadership of the Egyptian Meteorological Agency. External experts from the United States National Oceanic and Atmospheric Administration, the German Weather Service and the Czech Hydrometeorological Institute participated. Eight of the nine instruments were calibrated and made capable of measuring total ozone with better than 1 per cent accuracy, while one instrument was sent to Germany for repair and calibration before being returned to service.