Data Validation with GPCB

Case Information

Validation Equipment: Oizom Polludrone Pro

Reference: GPCB (Gujarat Pollution Control Board) Pollution Monitoring Station

Location: Kankaria-Maninagar (Ahmedabad)

Parameters: PM2.5, O3, NO2, CO

Duration : 8th August, 2016 to 7th September, 2016 (30 Days)


GPCB have their pollution monitoring station installed at Kankaria, Maninagar for continuous ambient air-quality monitoring. OIZOM took an opportunity to validate data from Polludrone-Pro by data-comparison with GPCB Pollution monitoring station.

For the validation purpose, Oizom installed two Polludrone-Pro equipments beside GPCB monitoring station to compare and check the data from low-cost ambient air-quality monitoring solution with regulatory board acceptable solution. Both the Polludrone equipments were installed beside the station from 8th August to 7th September 2016. PM2.5, CO, O3, NO2 are the air-quality parameters considered for the validation study. The data comparison study is represented on graphs in the case-study document.  Here, GPCB and OIZOM operates on different working principles, sampling rates, suction rate, sampling directions and technologies to monitor various environmental parameters.


Observation of Air-Pollutant


PM2.5 is a pollutant from man-made or natural sources like dust, ash, spray etc. We monitored data from both the solutions in Maninagar, which has been presented below, in terms of hourly averages and six-hour averages. Differences in value may be corrected by the advancement.

O3 By comparing the analysis of Ozone monitoring data from GPCB monitoring station and Polludrone-Pro, the data is following a similar pattern and showing correlations and deviations during different days, which might be an effect of weather conditions during those days

NO2 stands for the Nitrogen Dioxide and generated due to industrial and vehicular emission. The graphical representation shows the similarity in the pattern but there is a positive-negative deviation between both the systems on different day cycles.

CO Carbon monoxide is the most toxic gas commonly present in the ambient air. During the comparison study, it shows that the measurement of CO is perfectly matching for initial 8 days of the study. Afterward, a negative deviation is observed between the data from two systems, which might be an effect of weather conditions during those days.



On the basis of the presented validation study, the graphical comparison of the data collected by both the systems shows a level of correlations and deviations in different parameters at different time-spans. There are several factors responsible for the deviation stated below,

  • The air-suction points for both the systems were at different heights. GPCB Station takes air-suction from a height of 20-25 Feet where Polludrone Pro was installed at 6 Feet from the ground level.
  • Air-quality systems were situated at a 4m distance, which may also be a possible reason for the deviation.
  • Both the systems operate on different working principle. GPCB station has top suction method, where Polludrone has bottom suction method. GPCB station works on complex electrical sensing systems where Polludrone works on various electronic sensing systems.
  • Both the systems have different suction and sampling rates. GPCB station has high volume sampling with high suction flow-rate, where Polludrone has low volume sampling with lower suction flow-rate.
  • Both the systems are from different makes and works on different algorithms to derive air-quality measurements. In addition, both the systems are calibrated in a different way. This might be a possible reason for the deviation in the data.