use of spec sensor in arduino uno i have been trying to use NO2 spec senor in arduino UNO. how to write the code for it to get the output in terms of 'ppm' and how to give connection.with the helo of cross-sensitivity given in datasheet how to detect the interference gases from this sensor itself..the datasheet URL:

https://www.spec-sensors.com/wp-content/uploads/2016/10/3SP_NO2_5F-C-Package-110-508.pdf
In the specification sheet linked to in the post we find this:


  -30+/-10nA/ppm


This is a very small amount of current.  The Arduino ADC is a voltage sensing device and (unless modified) has a range of 0 to the operating voltage of the Arduino.  Usually 3.3V or 5V.

Converting nano Amps to that range of voltage will require additional hardware.  A stock Arduino and code are unlikely to make use of such a sensor.

The conversion of such small amounts of current to voltages measurable by a stock Arduino is not trivial. And most answers do not fit into the short format of stack exchange.  Here is an Engineering Design News article on the subject.