Please tell me if K-30 sensor can be used as a simple analog sensor by connecting its analog pin to arduino board?
No .Its not that .It is the one in the following link http://www.co2meter.com/products/k-30-co2-sensor-module
Yes. From one of the pdf references on that product:
Only outputs OUT1 and OUT2 can be configured as analog outputs. OUT3 and OUT4 are restricted to digital outputs by sensor hardware. Note that the available output range of OUT1 is 0..10V while OUT2 is 0..5V.
Sounds like OUT2 can interface directly to an arduino analog input pin.
So it means that 0V of output 1 corresponds to 0 ppm and 4V (according to datasheet) to 2000ppm rt? And is output voltage is directly proportional to the ppm values(since it is given its linear output).Datasheet attached.
DS30-01 - K30.pdf (614 KB)