Associate professor of civil engineering S M Shiva Nagendra said these sensors, embedded in a device, can be set up anywhere for they require very little space. Seven sensors in the instrument will monitor temperature, humidity, carbon monoxide, carbon dioxide, nitrogen dioxide, ozone and particulate matter.

The present monitoring systems do not provide spatial variability. The data collected is limited to a particular site or location. Moreover, often such stations are situated in green locales where pollution levels are low. When the low-cost sensors are installed across the city, the data they record can be synchronised with information from existing systems, Nagendra said.

The present monitoring stations were set up for Rs 1.25 crore and have a monthly maintenance of Rs 5 lakh. The system IIT-M is planning to introduce will not only be cheap but also be zero-maintenance. Nagendra said the system will be eco-friendly and will use solar power for energy.

The team has fixed the low-cost sensors, procured from private firms, in several MTC buses and tested them. A prototype was kept at the late Abdul Kalam's memorial when it was inaugurated by Prime Minister Narendra Modi.

However, the project has certain limitations. The durability of the sensors under different environmental conditions, standardising calibration procedures and accuracy of data need to be sorted out, said Nagendra adding that once procured, calibration of the sensors will require one month.

Nagendra said these monitors can be part of the Smart City programme and can keep residents informed about pollution levels across the city. Data from the devices will be directed to a mobile app that will enable residents to easily access information about pollution levels with their cellphones, Nagendra said.