An Otago Regional Council (ORC) air quality monitor installed at the school looked like an alien or satellite, some pupils said.
Others compared it to a weather monitor, lamp-post or fridge.
The state-of-the art monitor was at another site in Ventry St and was moved when that site was sold, ORC environmental scientist Deborah Mills said.
The monitor was recently re-commissioned on Ministry of Education land across from the Alexandra Primary School buildings, to coincide with the beginning of ORC winter air quality monitoring in Otago.
Alexandra air quality had been monitored intermittently from 1998 to 2005 and hourly from 2005, Ms Mills said.
''With such a long period of data, ORC has developed a good understanding of air quality in the older residential areas of town [Alexandra] and has seen an improvement in air quality over the last 10 years,'' she said.
The new monitor location would reflect pollution levels in a more open, commercial/residential area and provide more information about Alexandra's air quality as a whole, Ms Mills said.
''PM10 are suspended particles in the air that are smaller than 10 micrometres in diameter.''
A micrometre is a thousandth of a millimetre.
In Alexandra and the other Otago towns the ORC monitored, the main source of PM10 was from domestic heating appliances, Ms Mills said.
''These particle concentrations peak during winter mornings and evenings - times of the day when it is coldest, and when there is little to no wind.''
Daily PM10 concentrations in Alexandra regularly exceeded guidelines in the National Environmental Standard for air quality and rules in the Otago Air Plan from May until August, but were relatively low during the rest of the year, Ms Mills said.
The ORC monitors air quality in Alexandra, Arrowtown, Mosgiel and Dunedin year-round, and in Milton, Balclutha, Clyde and Cromwell during winter.
Alexandra Primary School deputy principal Tiffany Kemp said pupils were excited about having the equipment across from their school, and would ''learn from the experts'' and take air quality information and messages back home to their families, she said.
