I am calibrating my sensors in the range of 600 ppb - 1 ppm. In my calibration, process is a bit complex. We vary gas concentration and first analyze it on NOx analyzer/FTIR and then based on observed concentration values, sensors are calibrated.
I just wanted to add that the load resistor for the tests that AmroQuandour mentioned may be taken from the graph and the air resistance value in the gases technical guide. \
How can I derive RL from looking at the calibration graph provided in the sensor guide?
My sensors were initially giving values 0.0000000 in such a low concentration but worked when I increased RL to 3 from 1.
I also wanted to add that one of our node is not working perfectly. I will check it again with the second stage of calibration, and if it doesn't work well I will inform you.