Ultra-low Noise AD Conversion Design for Measurement of Air Pollutants

The current paper discusses the design of the pollution and communication system which is capable to measure the H2S levels in very low concentrations in ppb range. The system also reads the temperature and humidity values from the analog output values and send the measured values to the remote server via GSM/GPRS connection, which are stored in MySQL table for further analysis and visualization. The ultra-low noise design of the AD conversion is proposed. To achieve better sensitivity all parts of the design such as AD converter, voltage reference and power supply IC are specially selected towards the better noise characteristics.